a new species of freshwater snapping shrimp, alpheus cyanoteles

A NEW SPECIES OF FRESHWATER SNAPPING SHRIMP, 

ALPHEUS CYANOTELES (DECAPODA: CARIDEA: ALPHEIDAE) 

FROM PENINSULAR MALAYSIA AND A REDESCRIPTION OF 

ALPHEUS PALUDICOLA KEMP, 1915 

ABSTRACT. - A new species of freshwater snapping shrimp, Alpheus cyanoteles 

(Decapoda: Caridea: Alpheidae) is described from Peninsular Malaysia. A comparison is 

made with its nearest congener, Alpheus paludicola Kemp, 1915. A lectotype is designated 

for Alpheus paludicola and an illustrated redescription is also provided. 

In the course of sampling freshwater streams of the Kota Tinggi district of Johor, 

Peninsular Malaysia in June to July 1995, a good series of a medium-sized snapping shrimp 

of the genus Alpheus was obtained. The waters of this drainage are permanent fresh waters, 

making this species the only true freshwater member of the genus Alpheus. This species 

clearly belongs to the A. edwardsi group as defined by Banner & Banner (1966) (modified 

from De Man, 1911) and closely resembles Alpheus paludicola Kemp, 1915. Johnson (1965, 

1966) referred to snapping shrimp from the same above area as A. paludicola (mispelled as 

Alpheus paludosus). Tweedie (1938) also reported an alpheid shrimp from the same area 

which was not identified. Upon comparing with type material of A. paludicola loaned from 

the Natural History Museum, London, the present specimens showed a number of consistently 

different characters from A. paludicola s. str. 

In this paper, the shrimp, Alpheus cyanoteles, new species, is described and figured. A 

lectotype is designated for A. paludicola to facilitate comparative work and a redescription 

with illustrations based on the lectotype and paralectotype is also provided. Brief comparisons 

are also made with two other closely related species of the A. edwardsi group from mangroves 

in Southeast Asia, namely Alpheus euphrosyne De Man, 1897, and Alpheus microrhynchus 

De Man, 1898, with variations in the latter species noted for comparative purposes. An 

identification key to the above species is provided. 

Darren C. J. Yeo, Peter K. L. Ng - Department of Zoology, National University of Singapore, Kent 

Ridge, Singapore 119260, Republic of Singapore.

The following abbreviations are used: tl (total length), cl (carapace length), chI (chela 

length), chb (chela breadth), mfl (movable finger length), mfb (movable finger breadth), ffl 

(fixed finger length), ffb (fixed finger breadth), isl (intermediate segment length), psI (proximal 

segment length), dl (dactylus length of third pereiopod), pI (propodus length of third 

pereiopod), ml (merus length of third pereiopod), ail (appendix intema length) and amI 

(appendix masculina length). The total length is measured from the tip of the rostrum to the 

distal margin of the telson. Carapace length is measured from the anterior margin of the 

orbital hood to the dorsal posterior margin of the carapace in lateral view. Antennular peduncle 

segment lengths are measured through the midline of the dorsally visible portions. 

Measurements of the chelae dsed in the descriptions are shown in Fig. I. Measurements of 

total length or carapac~ length of large specimens were made using dial callipers. 

Measurements of small parts were made from scales obtained directly with the aid of an 

objective micrometer set. All measurements ~e in millimetres. Types are deposited in the 

Natural History Museum, [formerly the British Museum of Natural History] (BMNH), 

London; Nationaal Naturhistorisch Museum [formerly the Rijksmuseum van Natuurlijke 

Historie] (RMNH), Leiden; and the Zoological Reference Collection (ZRC), Department of 

Zoology, National University of Singapore. 

Fig. 1. a. Schematic drawing of modified/large chela of Alpheus species with the measurements used 

in the present study. 1: movable finger length; 2: movable finger breadth; 3: fixed finger breadth; 4: 

chela length; 5: fixed finger length; 6: palm length; 7: chela breadth; 8: merus (the ischium is fused 

to the merus in the first pereiopod of Alpheus species and the whole article is referred to as "merus"). 

b. Schematic drawing of non-modified chela of first pereiopod of Alpheus species and the measurements 

used. 1: chela length; 2: palm length; 3: fixed fingerlength; 4: chela breadth; 5: movablefinger length.

Alpheus paludicola Kemp, 1915 

(Figs. 2, 3) 

Material examined. "Lectotype - 1 male (BMNH 1919.11.1.1), Outer Channel, Lake Chilka, 

Orissa, India, colI.I,S.Kemp, 1914. 

Para1ectotype - 1 male (BMNH 1919.11.1.2), same data as lectotype. 

Description of Lectotype. - Subcylindrical body form, body slightly laterally compressed. 

Rostrum (figs. 2a, c) without setae, very short, barely exceeding anterior margin of orbital 

hood, reaching over about 0.1 of dorsally visible portion of proximal segment of antennular 

peduncle, broadly triangular in dorsal view, dorsal carina obsolete, ventral carina very weakly 

developed, unarmed, lateral carina confluent with anterior margin of orbital hoods. 

Carapace (fig. 2a) glabrous, smooth; orbital hood margin (fig. 2c) totally concealing 

eyes dorsally and laterally, anterior margin slightly convex dorsally, orbitorostral grooves 

almost absent, inferior orbital angle feebly produced, rounded, pterygostomial angle slightly 

produced, blunt; cardiac notch distinct. 

Abdomen (fig. 2b) glabrous, smooth; sixth segment about 1.1 times length of fifth, 1.2 

times longer than deep, compressed, posterior lateral angle acute, posteroventral angle 

rounded; pleura of first three segments bluntly triangular, fourth broadly rounded, fifth 

subrectangular, posteroventral angle rounded. Telson (fig. 3b) about 1.3 times length of 

sixth segment, 1.5 times longer than anterior width, lateral margins subparallel proximally, 

slightly convergent distally, with two pairs of dorsal spines about 0.08 of telson length, 

anterior pair at 0.5 of telson length, posterior pair at 0.7 of telson length; posterior margin 

about 0.6 of anterior width, strongly convex, with numerous long plumose setae, with 

numerous small spines dorsally, with lateral spines missing. 

Antennule (fig. 2c) with peduncle robust, about 0.4 of carapace length, not exceeding 

scaphocerite and carpocerite; proximal segment about 1.8 times longer than width, distal 

margin entire and setose; stylocerite oval, not exceeding anterior margin of proximal segment; 

intermediate segment subcylindrical, subequal to proximal segment, about 1.1 times proximal 

segment length, 2.5 times longer than wide, distal margin entire and sparsely setose; distal 

segment about 0.1 of proximal segment length, non-setose; upper flagellum biramous, 

proximal 27 segments fused, with about 10 groups of aesthetascs, longer ramus slender, tip 

missing; lower flagellum slender, slightly exceeding upper flagellum, tip missing. 

Antenna (fig. 2c) with basicerite stout, with feebly developed, blunt ventrolateral tooth, 

carpocerite subcylindrical, distinctly exceeding antennular peduncle and scaphocerite, about 

8.3 times longer than wide, flagellum with tip missing, about 1.3 times carapace length, 

proximal segments not thickened; scaphocerite reaching anterior margin of distal segment 

of antennular peduncle, 1.8 times longer than wide, suboval, lateral margin slightly concave, 

with acute distolateral tooth not exceeding anterior margin of lamella.

Eyes (figs. 2a, c) entirely concealed by anterior and lateral margins of orbital hood, cornea 

about 0.07 times of carapace length. 

Mandible (fig. 3f) with corpus robust; palp 2-segmented, distal segment suboval, 

compressed, about 1.5 times longer than broad, with several short plumose setae on distal 

margin, proximal segment subconical, about 1.9 times longer than anterior width, anterior 

width 2.9 times greater than posterior width, with three plumose setae at anterior medial 

angle; molar process subcylindrical, obliquely truncate distally, exterior surface densely 

microspinulate distally with scoop-shaped process fringed with small tooth-like spines; incisor 

process robust, with 6 acute distal teeth, with several rows of smaller teeth posteriorly. 

Maxillula (fig. 3g) with bilobed palp (badly damaged), distal lobe larger than proximal lobe; 

upper lacinia normal, with lower distal margin bearing 2 rows of about 8 short simple spines 

and with spiniform sette proximally; lower lacinia slender (badly damaged), with 3 to 4 

stout spines distally, with numerous spiniform setae distally. Maxilla (fig. 3h) with short, 

stout palp, with single distal plumose seta, basal endite broad, with some indication of division 

into 2 lobes, with numerous short setulose setae medially, coxal endite narrower than basal 

endite, sparsely setose; scaphognathite with anterior lobe about 1.4 times longer than broad 

(posterior lobe missing). First maxilliped (fig. 3i) with slender, unsegmented palp, about 

0.5 times exopod length, with 4 plumose setae distally, several shorter setulose setae medially; 

basal endite simple, setose along medial margin; exopod tapering distally, curving medially, 

with several plumose setae distally, caridean lobe narrow, extending midway up exopod, 

with numerous marginal plumose setae, epipod large, simple. Second maxilliped (fig. 3j) 

with normal endopod, dactylar segment narrow with numerous spines and spiniform setae 

medially; propodal segment bluntly produced distally with numerous spines and spiniform 

setae distally; exopod curved medially, with plumose setae distally; epipod large, 

subrectangular. Third maxilliped (fig. 3k) with robust endopod reaching anterior end of 

carpocerite; ischiomerus fused to basis, combined segment about 4.1 times longer than broad, 

subcylindrical, sparsely setose laterally and medially; penultimate segment about 3.1 times 

longer than broad, subcylindrical, 0.4 times of combined segment length, sparsely setose 

laterally and medially; distal segment tapering distally, about 6.7 times longer than proximal 

width, 0.7 of combined segment length, medial aspect with about 20 transverse rows of 

serrulate spines, of increasing size distally, laterally sparsely setose; exopod slightly exceeding 

combined segment of endopod, with numerous plumose setae distally, with several serrulate 

setae laterally; coxa sparsely setose, with rounded distolateral plate. 

Large chela (figs. 2d, e) robust, about 2.4 times longer than broad, laterally compressed, 

carried with inner face dorsal and outer face ventral, fingers open obliquely. Palm 1.5 times 

longer than broad, sculptured on both outer and inner face; transverse groove of superior 

margin with anterior edge straight dorsally, with posterior edge rounded dorsally, posterior 

edge obtuse to floor of groove, groove continuous with quadrangular shaped depression on 

upper edge of outer face and with triangular shaped depression on upper edge of inner face; 

inferior margin with strong, rounded shoulder ventrally at base of fixed finger opposite 

dactylar articulation, distal depressed area continuing on lower edge of outer face as triangular 

groove to about 0.2 of breadth of palm, continuing on lower edge of inner face as deeper 

triangular groove to about 0.5 of breadth of palm, transverse ridge at base of fixed finger 

posteriorly delimiting the triangular groove on lower edge of inner face continues posteriorly 

almost parallel to inferior margin and terminating with it but separated from it by inferointernal 

groove extending almost entire length of palm; inner face with central transverse 

ridge terminated proximally by curved groove running to carpal articulation, with distal 

large shallow depression delimited posteriorly by this transverse ridge and anteriorly by

other transverse ridge at base of fixed finger. Dactylus compact, about 1.1 times longer than 

broad, 0.3 of chela length, laterally compressed, slightly overlapping distal end of fixed 

finger, molar process moderately well-developed, outer margin sparsely setose. Fixed finger 

compact, broad, with inner margin of both inner and outer face strongly angled distal to 

socket for housing dactylus tooth, about 0.4 of chela length, 3.4 times longer than breadth 

at angle (outer face) distal to socket, outer margin sparsely setose. Carpus small, rounded, 

cup-shaped, about 0.3 of merus length. Merus unarmed, robust, 2.7 times longer than broad, 

0.3 of chela length, slightly expanding distally. 

Small chela (fig. 2f) about 5.2 times longer than broad. Palm subcylindrical, 2.6 times 

longer than broad, sculpturing much less pronounced than large chela, superior margin with 

weak, shallow trl!Psver~e groove posterior to base of dactylus insertion, inferior margin 

with very faint trJnsverse ridge, outer and inner face with faint longitudinal groove running 

next to superior margin. Dactylus 'balaeniceps-shaped', broadened with widest point midway, 

narrowing to curved, acute tip distally, lateral margins fringed with spiniform setae which 

meet over superior surface proximal to.tip, about 0.5 of chela length. Fixed finger with 

laterally fringing spiniform setae in proximal half, slightly crossing tip of dactylus, 0.5 of 

chela length. Carpus subconical, about 0.3 of merus length. Merus unarmed, more slender 

than in large cheliped, about 3.4 times longer than broad, 0.4 of chela length. 

Second pereiopods (fig. 2g) slender; chela (fig. 2h) small, about 3.3 times longer than 

broad; palm 1.3 times longer than broad; dactylus with cutting edge entire, 0.6 of chela 

length; fixed finger with cutting edge entire, 0.6 of chela length; carpus 5-segmented, about 

3.2 times chela length, articles in approximate ratio of 10:6:2.5:2.5:4 (rounded offto nearest 

integer to facilitate comparison giving a ratio of 10:6:3:3:4); merus 0.6 of carpus length, 6.3 

times longer than broad, unarmed; ischium 1.1 times as long as merus, 6.7 times longer than 

broad. 

Third pereiopods (figs. 2i, j) relatively robust; dactylus simple, subspatulate, 0.5 times 

propodus length, 5.5 times longer than proximal width; propodus about 2.0 times longer 

than dactylus, 8.0 times as long as broad, with a pair of distoventral spines, with 2 ventral 

spines in proximal half, sparsely setose; carpus about 0.7 of propodus length, 4 times longer 

than distal width, unarmed; merus about 1.2 times propodus, 5.6 times as long as broad, 

unarmed; ischium about 0.4 of merus, 2.5 times longer than distal width, with single movable 

spine ventrolaterally; basis normal, coxa robust. Fourth pereiopods similar in proportions 

to third pereiopods. Fifth pereiopods (fig. 3a) similar in proportions to third and fourth 

pereiopods, more slender; propodus with about 10 ventrolateral transverse rows of serrulate 

setae, increasing in number and size distally. 

Pleopods normal; endopod of first pleopod (fig. 3d) slender, 5 times longer than wide, 

curved, with long plumose setae distally, medially and laterally; endopod of second pleopod 

(fig. 3e) 7 times longer than broad, with appendices at 0.3 of endopod; appendix masculina 

subcylindrical, 7.5 times longer than wide, with 4 long terminal spines; appendix intema 

long and slender, with distal cincinnuli, inserted just posterior to appendix masculina, about 

12.5 times as long as broad, 1.7 times appendix masculina length. 

Uropod (fig. 3b) protopod with acute distolaterallobe, rami exceeding posterior margin 

of telson; exopod 1.3 times longer than wide, lateral margin convex, with ventral submarginal 

setal fringe, distolateral angle subrectangular, with single stout movable spine medially, 

diaeresis straight, entire, distal lobe broadly rounded, with long plumose marginal setae,

with short spiniform marginal setae; endopod about 0.8 times exopod length, 1.4 times as 

long as broad. 

Paralectotype. - The paralectotype (carapace length 5.2 mm; total length about 14 mm) 

is smaller than the lectotype (carapace length 5.5 mm; total length about 18 mm). Slight 

variation between the two specimens examined is observed in the rostrum, eye, carapace, 

antennules, antennae, large chelae, ambulatory pereiopods, uropods and telson. The 

paralectotype has a slightly longer rostrum (about 0.2 of proximal segment of antennular 

peduncle versus 0.1 in the lectotype). The cornea of the paralectotype (0.06 of carapace 

length) is smaller than that

Remarks. - Alpheus paludicola was first described by Kemp (1915) from specimens 

from Lake Chilka, Orissa, India No holotype was designated. In the course of examining 

A. paludicola syntypes from BMNH, it was found that Kemp's description was inadequate 

for modem standards in certain respects. Thus the need for this illustrated and more detailed 

redescription, and the designation of a lectotype. 

The present specimens agree with the description given by Kemp (1915) in most aspects. 

There are, however, some differences which are discussed below. Kemp's (1915: 303) 

description states that the terminal spine of the stylocerite "does not reach the end of the 

segment" (proximal antennular peduncle segment). However, the stylocerite does reach the 

level of the anteribr margin of the proximal segment of the antennular peduncle in the present 

specimens. The merus of the large chelipeds of the present specimens (small males) is 

about 2.7 times longer than broad, while the original description gave the proportions as 2 

times in large males, 2.4 times in younger males and 2.7 times in adult females. The "very 

fine granulation" in the large chela noted by Kemp (1915: 304, pI 13: figs. 12, 13) is not 

visible. The sculpturing on the palm ofthe small chela described by Kemp (1915: 304, fig. 

33b) is hardly obvious and almost indistinguishable. Unlike the original description in which 

thepropodus of the third pereiopod is said to "bear long setae but no spines", the present 

specimens do have small spines on the propodus varying in number from 1 to 3. Finally, the 

uropods distinctly exceed the distal margin of the telson, contrary to Kemp's description 

which states that "the telson reaches as far as the uropods". 

The diagnostic characters of A. paludicola however, remain unchanged following this 

redescription and those used by Kemp (1915) are still applicable for distinguishing it from 

its close relatives. Alpheus paludicola belongs to the A. edwardsi group (sensu De Man, 

1911; Banner & Banner, 1966), its closest relatives being Alpheus euphrosyne De Man, 

1897, and A. microrhynchus De Man, 1898. Alpheus paludicola can be distinguished from 

both A. euphrosyne and A. microrhynchus by the following combination of characters: i) 

rostrum much shorter, reaching not more than 0.2 of proximal segment of the antennular 

peduncle versus rostrum relatively longer in relation to proximal segment of the antennular 

peduncle (0.4 to 0.5 in A. euphrosyne; 0.2 to 0.5 in A. microrhynchus); ii) rostrum broadly 

triangular in dorsal view versus rostrum more slender and acutely tapering in dorsal view; 

iii) more robust large chela (ratio of chllchb 2.4) with relatively more robust fingers (ratio 

ofmf1lmfb 1.1 to 1.3, ffl/ffb 2.6 to 3.4) versus more slender large chela (ratio of chllchb 2.4 

to 2.5 in A. euphrosyne; 2.5 to 2.7 in A. microrhynchus) with relatively more slender fingers 

(ratio ofmf1lmfb 1.6 to 1.8, ffl/ffb 3.8 to 4.5 in A. euphrosyne; mfl/mfb 1.5 to 1.7, fWffb 3.3 

to 3.8 in A. microrhynchus) (figs. 8a, d). It should be noted, however, that the two features 

of the rostrum mentioned above are less reliable when used for differentiating A. paludicola 

from A. microrhynchus as the latter species has a highly variable rostrum length (from 0.2 

to 0.5 times the length of the proximal segment of the antennular peduncle) and shape (broadly 

triangular to slender) (figs. 8b, c), with some variants having rostra almost identical to the 

former species. Alpheus paludicola can be further differentiated from A. euphrosyne by the 

presence on the inner face of the palm of the large chela of a transverse ridge midway along 

the length of the palm and a large shallow depressed area distal to it, bound anteriorly by a 

shorter transverse groove at the base of fixed finger (versus absence of these characters) as 

well as by its much larger eggs of about 1.4 mm in diameter (Kemp, 1915) (versus 0.5 mm 

in diameter). The ratio of carpal articles of the second pereiopod in A. paludicola (10:6:2:2:4) 

differs only slightly from that of A. euphrosyne (10:6:2:2:3) (see Banner & Banner, 1966)

Yeo & Ng: Redescription of Alpheus paludicola and a new Alpheus species 

abde abde 

Fig. 2. Alpheus paludicola Kemp, 1915. Lectotype male (cl 5.5 mm, tl about 18 mm) (BMNH 

1919.11.1.1), Lake Chilka, Orissa, India. a: lateral view of carapace; b: abdomen; c: dorsal view of 

anterior carapace; d: outer face face of of large chela of of left first pereiopod; e: inner face of large chela of left 

first pereiopod; f: balaeniceps-type small small chela chela of of right right first pereiopod; g: right second pereiopod; h: 

chela of right second pereiopod; i: i: right right third third pereiopod; j: propodus and dactylus of right third 

pereiopod. Pinnae of plumose setae setae of of scaphocerite not drawn in. Scales = 2.0 mm in a, b, d, e; 2.0 

mm in f; 1.0 mm in c, g; 0.5 mm in in h; 2.0 mm in i; 1.0 mm in j. 

44 

a 

f 

cg 

h

... , 

...."~: . 

Fig. 3. Alpheus paludicola Kemp, 1915. a, b, d - k, Lectotype male (cl 5.5 mm, tl about 18 mm) 

(BMNH 1919.11.1.1), Lake Chilka, Orissa, India. c, Paralectotype male (cl5.2 mm; tl about 14 mm) 

(BMNH 1919.11.1.2), same locality. a: right fifth pereiopod; b: uropod and telson; c: telson; d: endopod 

of right first pleopod; e: appendix masculina and appendix intema on endopod of right second pleopod; 

f: right mandible; g: right maxillule; h: left maxilla; i: right first maxilliped; j: right second maxilliped; 

k: right third maxilliped. Pinnae of plumose setae of telson and uropod, plumose setae of second 

pleopod and short spiniform marginal setae of uropod not drawn in. Scales = 1.0 mm in k; 0.5 mm 

in d, e; 2.0 mm in a - c, 0.3 mm in g; 1.0 mm in f, h - j.

and should be used only as a supporting diagnostic feature. Alpheus paludicola can be 

further distinguished from A. microrhynchus by the presence of a superior margin notch and 

a very feeble inferior margin notch in the small chela (versus absence of notches in margins 

of small chela). In addition, the length of the second carpal article in relation to the first in 

A. paludicola is almost double that in A. microrhynchus, as reflected in the ratio of carpal 

articles of the second pereiopod of 10:6:2:2:4 in the former species versus 10:3: I: 1:2 in the 

latter species (see Banner & Banner, 1966). Alpheus microrhynchus is also a larger species 

than A. paludicola. The largest specimen of A. microrhynchus examined was a female (ZRC 

1979.441) of total length 81.6 mm versus the lectotype of A. paludicola (BMNH 1919.11.1.1) 

total length 18 mm and the maximum size of 22 mm reported by Kemp (1915: 305). Kemp 

(1915) had also used the presence of a transverse ridge on the inner face of the palm of the 

large chela and conical shape' of the third pereiopod dactylus to differentiate A. paludicola 

from A. microrhynchut However, examination of several specimens of the latter species 

from the ZRC showed the ridge to be present (fig. 8a) and the dactylus to be subconical to 

subspatulate. In all other aspects, these specimens matched the description of A. 

microrhynchus given by Banner & Banner (1966) and De Man (1898). 

Alpheus paludicola has been reported from Tale Sap in southern Thailand (Kemp, in 

Annandale, 1918) and from lohor, Peninsular Malaysia as A. paludosus (Johnson, 1965, 

1966). However, the specimens from the former locality may not be A. paludicola s. str. and 

their true identity is debatable while those from the latter area belong to a new species (see 

Remarks under Alpheus cyanoteles, new species). 

Alpheus cyanoteles, new species 

(Figs. 4 - 7) 

Alpheus paludosus (sic) - Johnson, 1965: 9; 1966: 430; Powell, 1979: 117; Lovett, 1981: 67 (not 

Alpheus paludicola Kemp, 1915). 

Alpheus paludicola - Banner & Banner, 1966: 135. 

Material examined. - Ho10type - 1 male (ZRC 1996.1), Sungei Tementang, Kota Tinggi, Johore, 

1°52'0.81"N 103°55'49.2"E, colI. P.K.L.Ng et aI., 5 Jun.1995. 

Paratypes - 8 males, 7 females (ZRC 1996.2), same data as holotype.- 3 males, 3 females (ZRC 

1996.3), same locality data as holotype, coIl. D.C.J.Yeo et aI., 31 Ju1.l995.- 3 males, 5 females (ZRC 

1996.4), Sungei Selangi, Kota Tinggi, Johore, 1°51' 46.5"N 104°00'31.0"E, colI. P.K.L.Ng et aI., 5 

Jun.1995.- 1 female (ZRC 1996.58), same data as holotype.- 3 males, 4 females (BMNH), Sungei 

Selangi, Kota Tinggi, Johore, 1051'46.5"N 104°00'31.0"E, coIl. D.C.J.Yeo et aI., 31 Ju1.l995.- I 

female (ZRC 1979.4415), Sungei Semalok, big stream at 93/4 mile Kota Tinggi-Mawai Road, Johore, 

colI. D.S.Johnson, 5 May.1960.- 1 female (ZRC 1992.8382), Johore, Mawai-Sedili Road, colI. 

P.K.L.Ng, 14 Aug. 1991.- 2 males (ZRC 1992.8383-8384), Johore, stream along Mawai-Tanjung Sedili 

Road, freshwater above tidal influence, colI. P.K.L.Ng, 14 Aug.1991.- I male (ZRC 1992.8385), 

Malaysia, Johore, Sedili area, no data on collector and date .- 2 males 2 females (RMNH), Malaysia, 

Johore, Kota Tinggi, Sungei Tementang, coIl. A.Y.H.Lim, H.H.Tan & S.H.Tan, 24 Feb. 1995.- 2 males 

(RMNH), Sungei Tementang, Kota Tinggi, Johore, P.K.L.Ng et aI., 7 Sep.1995. 

Others - 2 females (ZRC 1996.5), Sungei Selangi, Kota Tinggi, Johore, coIl. P.K.L.Ng et aI., 

1994.- I male, 1 female (ZRC 1996.46), no data. 

Description of paratype. - Subcylindrical body form. 

Rostrum (figs. 5a, b) without setae, short, distinctly exceeding anterior margin of orbital

hood, about 0.3 of dorsally visible portion of proximal segment of antennular peduncle, 

acutely tapered in dorsal view, dorsal carina obsolete, ventral carina very weakly developed, 

unarmed, lateral carina obsolete. 

Carapace (fig. 5b) glabrous, smooth; orbital hood margin totally concealing eyes dorsally 

and laterally, anterior margin slightly convex dorsally, orbitorostral grooves slight, inferior 

orbital angle indistinct, pterygostomial angle not produced, rounded; cardiac notch distinct. 

Abdomen (fig. 5c) glabrous, smooth; sixth segment about 1.1 times length of fifth, 1.2 times 

longer than deep, compressed, posterior lateral angle acute, posteroventral angle blunt; pleura 

of first four segments broadly rounded, fifth subrectangular, posteroventral angle rounded. 

Telson (figs. 5j) about 1.2 times length of sixth segment, 1.3 times longer than anterior 

width, lateral mar,gins subparallel proximally, slightly convergent distally, with two pairs of 

dorsal spines abdUt 0.08 of telson length, anterior pair at 0.5 of telson length, posterior pair 

at 0.8 of telson length; posterior margin broad, about 0.7 of anterior width, with small, 

subequal, spines laterally, 4 on left side, 2 on right side, about 0.3 of dorsal spines length, 

broadly convex, with numerous long plumose setae, with numerous small spines dorsally. 

Antennule (fig. 5a) with peduncle robust, about 0.3 of carapace length, not exceeding 

scaphocerite and carpocerite; proximal segment about 1.2 times longer than width, distal 

margin entire and sparsely setose; stylocerite oval-shaped, with terminal distal spine not 

exceeding anterior margin of proximal segment; intermediate segment subcylindrical, 

distinctly longer than proximal segment, about 1.4 times proximal segment length, 1.9 times 

longer than wide, distal margin entire and sparsely setose; distal segment about 0.6 of proximal 

segment length, distal margin entire and sparsely setose; upper flagellum biramous, proximal 

28 segments fused, shorter ramus with 1 free segment, with about 16 groups of aesthetascs, 

longer ramus slender, tip missing; lower flagellum slender, about 1.1 times carapace length. 

Antenna (fig. 5a) with basicerite robust, with acute ventrolateral tooth, not reaching midway 

of proximal segment of antennular peduncle, carpocerite subcylindrical, distinctly exceeding 

antennular peduncle and scaphocerite, about 5.5 times longer than wide, flagellum, about 

2.4 times carapace length, proximal segments not thickened; scaphocerite not exceeding 

anterior margin of distal segment of antennular peduncle, 1.9 times longer than wide, suboval, 

lateral margin straight, with acute distolateral tooth not exceeding anterior margin of lamella. 

Eyes (figs. 5a, b) entirely concealed by anterior and lateral margins of orbital hood, cornea 

about 0.04 times of carapace length. 

Mandible (fig. 7a) with corpus robust; palp 2-segmented, distal segment suboval, 

compressed, about 1.5 times longer than broad, with several short plumose setae on distal 

margin, proximal segment subcylindrical; molar process subcylindrical, truncate distally, 

exterior surface densely microspinulate distally with scoop-shaped process with fringe of 

small tooth-like spines; incisor process robust, with 10 acute distal teeth. Maxillula (fig. 7b) 

with bilobed palp, distal lobe larger than proximal lobe, proximal lobe with long, slender, 

simple seta distally; upper lacinia normal, with lower distal margin bearing about 2 rows of 

10 to 12 stout, simple spines and with numerous submarginal spiniform setae; lower lacinia 

slender, curved, with about 4 stout spines distally, with numerous spiniform setae distally. 

Maxilla (fig. 7c) with short, stout palp, with single distal plumose seta, basal endite broad, 

weakly bilobed, with numerous short, stout, setulose setae medially, coxal endite weakly 

developed, sparsely setose; scaphognathite normal, about 5.6 times as long as broad, with 

posterior lobe about 3.9 times longer than broad, with anterior lobe about 1.4 times longer 

than broad. First maxilliped (fig. 7d) with slender, 2-segmented palp, about 0.5 times exopod 

length, distal segment subcylindrical, tapering distally, about 4 times longer than broad, 0.4 

of proximal segment length, with single plumose seta distally, proximal segment slender,

curved about 8.6 times longer than broad, with shorter setulose setae medially; basal endite 

simple, setose along medial margin; exopod well developed, with numerous plumose setae 

distally, caridean lobe narrow, extending midway up exopod, with numerous marginal 

plumose setae, epipod large, simple. Second maxilliped (fig. 7e) with normal endopod, 

dactylar segment narrow, with 3 large spines distomedially, with numerous small spines and 

spiniform setae medially; propodal segment bluntly produced distally with numerous spines 

and spiniform setae distally; exopod curved, with plumose setae distally; epipod large, 

subrectangular. Third maxilliped (fig. 7f) with robust endopod not exceeding anterior end 

of carpocerite; ischiomerus fused to basis, combined segment, subcylindrical, about 4.3 times 

longer than broad, sparsely setose laterally and medially; penultimate segment about 4.4 

times longer than broad, subcylindrical, 0.4 of combined segment length, sparsely setose 

laterally and medially; distal··segment tapering distally, about 8.9 times longer than broad, 

0.7 of combined segmt!ht length, medial aspect with numerous rows of serrulate spines, of 

increasing size distally, laterally sparsely setose; exopod exceeding combined segment of 

endopod, with numerous plumose setae distally, with several serrulate setae distally; coxa 

sparsely setose, with rounded distolateral plate. 

Large chela (figs. 5d, e) robust, about 2.6 times longer than broad, laterally compressed, 

carried with inner face dorsal and outer face ventral, fingers open obliquely. Palm 1.3 times 

longer than broad, sculptured on both outer and inner face; transverse groove of superior 

margin linking quadrangular shaped depressed area on upper edge of outer face and with 

triangular shaped depressed area on upper edge of inner face, with anterior edge of groove 

straight dorsally, with posterior edge rounded dorsally, posterior edge obtuse to floor of 

groove; inferior margin with strong, rounded shoulder ventrally near base of fixed finger 

opposite dactylar articulation, with depressed area distally, continuing on lower edge of outer 

face as triangular groove to about 0.2 of breadth of palm, continuing on lower edge of inner 

face as deeper triangular groove to about 0.5 of breadth of palm, transverse ridge at base of 

fixed finger posterior to and delimiting inner face lower edge triangular groove continues 

posteriorly almost parallel to inferior margin terminating with it but separated from it by 

infero-intemal groove extending almost entire length of palm; inner face with central 

transverse ridge bound proximally by curved groove running to carpal articulation, with 

distal large shallow depression delimited posteriorly by this transverse ridge and anteriorly 

by other transverse ridge at base of fixed finger. Dactylus with tip broken, elongated, about 

1.9 times longer than broad, 0.4 of chela length, laterally compressed, slightly overlapping 

distal end of fixed finger, molar process well-developed, outer margin sparsely setose. Fixed 

finger elongated, broad, with inner margin of both inner and outer face slightly produced in 

blunt angle distal to socket for housing dactylus tooth, about 0.5 of chela length, 4.1 times 

as longer than breadth at angle (outer face) distal to socket for housing dactylus tooth, outer 

margin sparsely setose. Carpus small, rounded, cup-shaped, about 0.2 of merus length. Merus 

unarmed, robust, 2.7 times longer than broad, 0.3 of chela length, slightly expanding distally. 

Small chela (fig. 5f) about 5 times longer than broad. Palm subcylindrical, 2.6 times longer 

than broad, sculpturing much less pronounced than large chela, superior margin with shallow 

transverse groove posterior to base of dactylus insertion, inferior margin with very weak 

transverse ridge, outer and inner face with longitudinal groove running next to superior margin. 

Dactylus 'balaeniceps-shaped', broadened with widest point midway, narrowing to curved, 

acute tip distally, lateral margins fringed with spiniform setae which meet over superior 

surface proximal to tip, about 0.4 of chela length. Fixed finger with sparse laterally fringing 

spiniform setae, slightly crossing tip of dactylus, 0.5 of chela length. Carpus subconical, 

about 0.3 of merus length. Merus unarmed, more slender than in large cheliped, about 3.6 

times longer than broad, 0.4 of chela length.

Second pereiopods (fig. 5h) slender; chela (fig. 5i) small, about 3.2 times longer than 

broad; palm 1.2 times as long as broad; dactylus with cutting edge entire, 0.6 of chela length; 

fixed finger with cutting edge entire, 0.6 of chela length; carpus 5-segmented, about 4.3 

times chela length, articles in approximate ratio of 10:3.5:1.5:1.5:2.5; merus slender, 9.2 

times longer than broad, 0.7 of carpus length, unarmed; ischium slender, 8 times longer than 

broad, 0.9 times as long as merus; basis normal; coxa robust. 

Third pereiopods (figs. 6a, b) relatively robust; dactylus simple, subspatulate, 0.3 times 

propodus length, 3 times longer than proximal width; propodus about 2.9 times longer than 

dactylus, 7.2 times as long as broad, with a pair of distoventral spines, with 8 ventral spines, 

sparsely setose; carpus about 0.7 of propodus length, 4.6 times longer than distal width, 

unarmed; merus !lbout 'iA times propodus, 6.6 times as long as broad, unarmed; ischium 

about 004 of merKs, 204 times longer than distal width; basis normal, coxa robust. Fourth 

pereiopods (figs. 6c, d) similar to third pereiopods; dactylus simple, subspatulate, 0.3 times 

propodus length, 3.7 times longer than proximal width; propodus about 3.7 times longer 

than dactylus, 8.2 times longer than broad, with a pair of distoventral spines, with 8 ventral 

spines, sparsely setose; carpus about 0.7 of propodus length, 4.7 times longer than distal 

width, unarmed; merus about 1.2 times propodus, 6 times as long as broad, unarmed; ischium 

about 004 of merus, 3 times longer than distal width; basis normal, coxa robust. Fifth 

pereiopods (figs. 6e, f) similar to third and fourth pereiopods but more slender; dactylus 

simple, sub spatulate, 004 times propodus length, 5 times longer than proximal width; propodus 

about 2.7 times longer than dactylus, 10 times as long as broad, with a pair of distoventral 

spines, with 3 ventromedial spines, with 1 distal ventromedial spine, with several ventrolateral 

transverse rows of serrulate setae, increasing in size and number distally; carpus about 0.9 

of propodus length, 6.8 times longer than distal width, unarmed; merus about subequal to 

propodus length, 5.7 times as long as broad, unarmed; ischium about 0.6 ofmerus, 4.4 times 

longer than distal width; basis normal, coxa robust. 

Pleopods normal; endopod of first pleopod (fig. 6g) slender, 7 times longer than wide, 

curved, with long plumose setae distally and medially and laterally; endopod of second 

pleopod (fig. 6h) 5.7 times longer than broad, with appendices at about 0.3 of endopod; 

appendix masculina subcylindrical, 8.8 times longer than wide, with 5 long spines distally; 

appendix intema subequal in length to appendix masculina, with distal cincinnuli, inserted 

just posterior to appendix masculina, about 8.8 times as long as broad. 

Uropod (fig. 5j) protopod with acute distolaterallobe, rami exceeding posterior margin 

of telson; exopod 1.3 times longer than wide, lateral margin convex, with submarginal setal 

fringe ventrally, diaeresis straight, entire, with stout movable lateral spine, flanked by small 

acute fixed tooth medially, with small acute tooth laterally; distal lobe broadly rounded, 

with numerous long plumose marginal setae, with short spiniform marginal setae; endopod 

about 0.9 times exopod length, 104times as long as broad. 

Variation. - The holotype (ZRC 1996.1) (carapace length 13.7 mm; total length about 

35.7 mm) (fig. 4) is larger than the described paratype (ZRC 1996.2) (carapace length 1104 

mm, total length about 31.1 mm). Deviations from the paratype description observed in the 

holotype are primarily in the antennular peduncle and the large chela. The antennular peduncle 

of the holotype slightly exceeds the carpocerite and scaphocerite (while not exceeding in the 

paratype). In addition, the antennular peduncle segments also show slight differences: i) the

proximal segment is more robust in the holotype than in the paratype (1.1 times as long as 

broad versus 1.2 times); ii) intermediate segment is relatively longer (ratio of isUpsl 1.7 

versus 1.4); iii) the intermediate segment is more slender (2.2 times as long as broad versus 

1.9 times). The large chela of the holotype (2.5 times as long as broad) is slightly less 

slender than that of the paratype (2.6 times as long as broad). The fingers of the large chela 

of the holotype are correspondingly slightly more robust (ratio of mfUmfb 1.4 versus 1.9 ; 

ratio of fWffb 3.9 versus 4.1). 

Within the series of specimens examined, variation in the following parts was also noted: 

Rostrum. - The rostral length relative to the proximal segment of the antennular peduncle 

varies from about 0.3 to 0.5. ~-.. 

Carapace.- The antbrior margin of the orbital hood rarely conceals the eye partially in the 

lateral view and from the dorsal view, varies from convex to slightly convex, rarely straight. 

The inferior orbital angle ranges from being very weak:, not produced to being indistinct and 

obsolete. 

Abdomen.- The telson length in proportion to the 6th segment and its own anterior width 

ranges from 1.1 to 1.3 and 1 to 1.5 respectively. The dorsal spine length in relation to telson 

length varies from 0.06 to 0.1. The posterior telson width varies in relation to the anterior 

width (0.6 to 0.8 times). The paratype described is unusual in having 4 lateral spines on the 

left side of the posterior margin of the telson (fig. 5j). All other specimens have 2 pairs of 

unequal lateral spines on the posterior margin (fig. 5k). The smaller lateral pair being subequal 

(0.1 to 0.8 of dorsal spine) and the longer medial pair being subequal (0.2 to 0.5 of dorsal 

spine). 

Antennules.- The intermediate segment of the antennular peduncle is distinctly longer 

than the proximal to varying degrees (1.3 to 2 times) while the distal segment also varies 

with respect to the proximal segment (0.6 to 1 times). 

Antennae.- The ventrolateral tooth of the basicerite is usually acute and stout, reaching 

or nearly reaching about half of the proximal segment of the antennular peduncle. It rarely 

exists as a slight acute projection. The carpocerite ranges from slightly shorter than the 

antennular peduncle to being about subequal to or slightly exceeding it. The scaphocerite 

length is also variable in relation to the antennular peduncle (from slightly shorter than to 

just exceeding). In the scaphocerite, the lateral tooth varies from not exceeding the anterior 

margin of the lamella to distinctly exceeding. 

First pereiopods.- The slenderness of the large chela varies from 2.5 to 3 times as long 

as broad. The relation of the dactylus length to the chela length varies little (0.4 to 0.5 

times). The dactylus also varies in breadth (1.4 to 2 times as long as wide). There is also 

little variation in the fixed finger length in proportion to the chela length (0.4 - 0.5 times). 

The fixed finger also varies in broadness (3.4 to 4.1 times as long as wide). In the small 

chela, the length with respect to breadth ranges between 4.9 to 6.4 times. There is sexual 

dimorphism exhibited with the dactylus of males being 'balaeniceps-shaped' while that of 

females being normal (fig. 5g). The subequal fingers of the small chela vary from 0.4 to 0.5 

times of the chela length. In general, the more slender chelae and fingers for both large and 

small chelae are found in females and small males, however this is not always the case. The

sculpturing on the palm of the large chela varies in intensity from individual to individual 

but the pattern remaining the same. In the small chela, sculpturing on the palm ranges from 

being absent to faint. 

Second pereiopods.- The merus length in relation to the carpus length varies from 0.6 to 

0.8 times. The ratio of carpus articles in relation to the first carpus article also shows some 

variation giving an average ratio of about 10:4:1.7: 1.7:2.8 (expressed to nearest integer for 

clarity and easy comparison gives a ratio of 10:4:2:2:3). 

Third pereiopods.- The range of relative proportions used are as follows: dactylus (0.3 

to 0.4 times of propodus), propodus (2.6 to 3.1 times longer than dactylus), carpus (0.7 to 

0.8 times of propodus);' ., merus (1.3 to 1.5 times longer than propodus), ischium (0.4 to 0.6 

times of merus). 'The number of ventral spines of the propodus ranges from 6 to 8. 

Second pleopods.- The position ofthe appendix interna (and appendix masculina in males) 

varies from being inserted at 0.2 to 0.3 of the endopod. In males, the length of the appendix 

interna with respect to the appendix masculina ranges from 1 to 1.3 times. 

Uropods.- Proportions vary in the exopod (1.2 to 1.4 times as long as broad) and endopod 

(1.1 to 1.6 times as long as broad). The length of the endopod with respect to the exopod 

ranges between 0.8 to 0.9 times. 

Etymology. - Cyanote/es, latinized from the Greek words kyanos meaning dark blue and 

te/os meaning end, referring to the bluish colouration of the telson and uropods. Used as a 

collective noun in apposition. 

Fig. 4. Alpheus cyanoteles, new species. Holotype male (ZRC 1996.1) (dl3.7 mm; tl about 35.7 mm). 

Scale = 1.0 mm.

~ 

bcdefh 

Fig. 5. Alpheus cyanoteles, new species. a - f, h, i, Paratype male (clll.4 mm, tl about 31.1 mm) 

(ZRC 1996.2), Sungei Tementang, Kota Tinggi, Johore, Peninsular Malaysia. g, Paratype female (cl 

15.1 mm, tl about 46.2 mm) (ZRC 1996.58), same locality. k, Paratype male (cl6.6 mm, tl about 18.8 

mm) (RMNH), same locality. a: dorsal view of anterior carapace; b: lateral view of carapace; c: 

abdomen; d: outer face of large chela of right first pereiopod; e: inner face of large chela of right first 

pereiopod; f: balaeniceps-type small chela of left first pereiopod; g: small chela of left first pereiopod; 

h: right second pereiopod; i: chela of right second pereiopod; j uropod and telson; k: posterior margin 

of telson. Pinnae of plumose setae, short spines oftelson posterior margin and short spiniform marginal 

setae of uropod not drawn in. Scales = 2.0 mm in a, j; 5.0 mm in b - f, h; 0.5 mm in k; 5.0 mm in g; 

0.5 mm in i.

~~;;; 

.' b 

Fig. 6. Alpheus cyanoteles, new species. Paratype male (cIlIA mm, tl about 31.1 mm) (ZRC 1996.2), 

Sungei Tementang, Kota Tinggi, Johore, Peninsular Malaysia. a: right third pereiopod; b: propodus 

and dactylus of right third pereiopod; c: right fourth pereiopod; d: propodus and dactylus of right 

fourth pereiopod; e. right fifth pereiopod; f: propodus and dactylus of right fifth pereiopod; g: endopod 

of right first pleopod; h: appendix masculina and appendix intema on endopod of right second pleopod. 

Plumose setae of second pleopod not drawn in. Scales = 5.0 mm in a, c, e; 2.0 mm in b, d, f; 1.0 mm 

in g; 2.0 mm in h.

Yeo & Ng: Redescription of Alpheus paludicola and a new Alpheus species 

Fig. 7. Alpheus cyanoteles, new species. Paratype male (cll1.4 mm, tl about 31.1 mm) (ZRC 1996.2), 

Sungei Tementang, Kota Tinggi, Iohore, Johore, Peninsular Malaysia. a: left mandible; b: right maxillule; maxillule; c: c: 

right maxilla; d: right first maxilliped; e: right second maxilliped; f: right third maxilliped. Scales = 

2.0 mm in a, b; 1.0 mm in c - e; 2.0 mm in f. 

54 

ab 

f 

cde

Colour. - The carapace and most of the abdomen oflive specimens is a dark transluscent 

grey. Dorsally, there are transverse bands of dark blue on the posterior edge of the carapace 

and each abdominal segment. The telson is dark blue in the posterior half. The uropod is 

generally blue to dark blue, especially in the distal lobes of the endopod and exopod. The 

antennules and antennae are light translucent grey with a light bluish tinge. The fingers of 

the large chela, except for pinkish fingertips, are dark bluish gradually becoming a lighter 

greyish blue posteriorly in the palm. The small chela is grey with light bluish fingers and 

the remaining pereiopods and pleopods are light greyish and transluscent. Aquarium kept 

specimens retain their natural colouration (pers. observ.). 

Ecology. - Alpheus cyanoteles is a true freshwater shrimp, found in freshwater streams, 

above tidal influeJilce, in the Kota Tinggi drainage of Johor, Peninsular Malaysia (see fig. 9). 

These forest streJrns are well-shaded and have a sand and clay substrate with clear, flowing 

water of variable depth (40 - 100 cm). The pH and conductivity of the water is about 4.7 

(Sungei Tementang) to 5.8 (Sungei Selangi) and not more than 24 microsiemens respectively. 

Syntopic organisms include the shrimps Caridina sp., Macrobrachium malayanum, 

Macrobrachium platycheles (see Ou & Yeo, 1995), Macrobrachium trompi and 

Potamalpheops sp. (pers. observ.); fishes include: Cyclocheilichthys apogon, Osteocheilus 

hasselti, O. microcephalus, Rasbora bankanensis, R. cephalotaenia, R. elegans, R. 

heteromorpha, R. trilineata, Puntius binotatus (Cyprinidae), Homaloptera tweediei, 

Nemacheilus selangoricus, (Balitoridae), Lepidocephalichthys tomaculum, Pangio kuhlii 

(Cobitidae), Hemibagrus hoeveni, Leiocassis fuscus, L. stenomus, Mystus singaringam 

(Bagridae), Krytopterus macrocephalus, Silurichthys sp., Wallago leerii (Siluridae), Parakysis 

verrucosus (Akysidae), Glyptothorax cf. major (Sisoridae), Hemirhamphodon pogonognathus 

(Hemiramphidae), Phenacostethus smithi (Phallostethidae), Doryichthys martensi 

(Syngnathidae), Monopterus albus (Synbranchidae), Nandus nebulosus (Nandidae), 

Pristolepis grooti (Pristolepididae), Brachygobius xanthomelas, Pseudogobiopsis siamensis 

(Gobiidae), Luciocephalus pulcher (Luciocephalidae), Betta pugnax, B. tomi, Trichopsis 

vittata (Belontiidae), Channa gachua, C. lucius (Channidae); and the freshwater crab, 

Parathelphusa maculata. (H.H.Tan, pers. comm.; pers. observ.). Most specimens of A. 

cyanoteles were obtained from below vertical muddy banks with overhangs held in place 

by vegetation and root systems. It is likely that these shrimp have a preference for building 

their burrows along the stream bottom, at or near the base of the submerged part of such 

sheltered banks as many specimens were collected by scooping a tray net deep down to the 

bottom and then upwards against the vertical bank. 

The eggs of A. cyanoteles are relatively few and large (about 1.5 mm in diameter). Some 

larvae were obtained from ovigerous female specimens kept in aquaria and these were of the 

highly abbreviated type (see Chong & Khoo, 1987). 

Referring toA. cyanoteles as A. paludicola, Johnson (1965,1966) regarded A. paludicola 

primarily as a prawn inhabiting lower salinity brackish waters. In his review of brackish 

water prawns of Malaya, Johnson (1965) referred to A. paludicola as a characteristic species 

of oligohaline waters, together with other prawns like Caridina gracilirostris, C. propinqua, 

C. tonkinensis and C. thambipillaii. Johnson (1966) again made reference to A. paludicola 

in a discussion on factors influencing distribution of freshwater prawns in Malaya, citing it 

as an example of a species characteristic of oligohaline waters being able to survive in true 

freshwaters or "soft, acid waters near the sea". Thus it would appear that the habitat occupied 

by A. cyanoteles ranges from freshwater to oligohaline brackish water. In the present study, 

only freshwater habitats in Kota Tinggi, Johore [Peninsular Malaysia] were sampled and no

detailed surveys further downstream (i.e closer to the sea) were conducted. As such no 

specimens from brackish waters were obtained for examination. Furthermore, there has 

been rapid development of the area since Johnson (1965, 1966) collected specimens of this 

species in the 1960s or earlier, making it almost impossible to be sure if recent collections 

in the same area are from the original sites sampled by Johnson. However, from the present 

large sample size including ovigerous females obtained from fresh waters, it is clear that A. 

cyanoteles is an established freshwater inhabitant and not merely a brackish water prawn 

able to tolerate low salinities. That it can tolerate brackish waters is also interesting but 

secondary to the present contention that it can survive wholly in freshwater. Banner & 

Banner (1966) mentioned A. paludicola and Powell (1979) and Lovett (1981) mentioned 

"A. paludosus" (sic) in discussions on freshwater alpheids based on Johnson (1965, 1966) . 

.. 

Remarks. - Alpheui' cyanoteles belongs to the A. edwardsi group (sensu De Man, 1911; 

Banner & Banner, 1966) and is related to Alpheus paludicola Kemp, 1915, Alpheus 

euphrosyne De Man, 1897 and Alpheus microrhynchus De Man, 1898. Its closest congener 

is A. paludicola. with which it has been mistaken for in the past. A. cyanoteles can be 

distinguished from A. paludicola mainly by characters in the rostrum (figs. 2c, 5a), antennule 

(figs. 2c, 5a), antenna (figs. 2a, c, 5a, b), large chela (figs. 2d, e, 5d, e), second pereiopod 

(figs. 2g, 5h), third pereiopod (figs. 2i,j, 6a, b), fifth pereiopod (figs. 3a, 6e), second pleopod 

(figs. 3e, 6h), exopod of uropod (figs. 3b, 5j), telsoJl (figs. 3b, c, 5j) and first maxilliped 

(figs. 3i, 7d) (See table 1 for comparison). In addition, some other consistent but less reliable 

differences are noted between the two species. Firstly, A. cyanoteles is a larger species than 

A. paludicola. The largest specimen examined from the former species was an ovigerous 

female of total length 46.2 mm from Sungei Tementang (ZRC 1996.58), compared to the 

lectotype of A. paludicola (BM 1919.11.1.1) totallength 18 mm. Kemp (1915: 305) reported 

that " ...large specimens ...reach a length of about 22 mm", which are still smaller than large 

specimens of A. cyanoteles. With regards to the carapace, the anterior margin of the orbital 

hood tends to be convex dorsally in A. cyanoteles versus straight in A. paludicola. The 

inferior orbital and pterygostomial angles of the anterior margin of the carapace are indistinct 

or very weak, rounded and never produced in A. cyanoteles while in A. paludicola, these 

angles are almost always feebly produced. In terms oflive colouration, the telson and uropods 

in A. paludicola are dusky (Kemp, 1915) while in A. cyanoteles, they are blue to dark blue. 

The habitat of A. cyanoteles differs from that of A. paludicola. The streams in Kota Tinggi 

from which A. cyanoteles specimens were collected from are true freshwater forest streams 

while Lake Chilka, being a coastal lake with direct connection to the sea, has polyhaline 

waters, spatially and seasonally varying in salinity from almost that of freshwater to that of 

the adjacent Bay of Bengal. Alpheus cyanoteles and A. paludicola are also not sympatric, 

with the latter being reported only from the type locality, Lake Chilka, Orissa, India (Kemp, 

1915) and from Tale Sap, southern Thailand (Kemp, 1918). 

The specimens of Alpheus paludicola reported from Tale Sap in southern Thailand, a 

coastal lake similar to Lake Chilka in the type locality, Orissa, by Kemp (Kemp in Annandale, 

1918:273) were described by him as follows: "The only difference I am able to detect between 

specimens collected by Dr. Annandale in Lower Siam and those originally described from 

Chilka Lake in Orissa is that the rostrum is very slender and rather longer, extending 

considerably beyond the end of the orbital hoods. In the form of the chelae and in all other 

particulars there is precise agreement. The eggs are 1.3 or 1.4 mm in diameter. 

According to Dr. Annandale's notes the specimens differed somewhat in colour from 

those observed in the Chilka Lake, the transverse bands of pigment on the abdomen are

missing. They were transluscent, without definite markings, but tinged, owing to the presence 

of scattered chromatophores, with reddish brown. The eyes were black and the palm and 

fingers of both chelae were deeply tinged with blue, especially on the dorsal surface. The 

eggs were pale green. 

The specimens were obtained in the Tale Sap, in the channel connecting the upper and 

lower lakes at a depth of 3 1 / 2 to 8 metres. They were found in a shallow layer of dense mud 

overlying a coarse sandy bottom and occurred in company with Upogebia heterocheir. The 

specific gravity of the water in the channel was variable according to the state of the tide, 

but probably does not rise much above 1.004." No data for size of specimens or number of 

specimens were provid~d. 

Determining the true identity of these specimens from the above description alone is a 

problem as there are several pieces of apparently conflicting information. In the form of the 

rostrum being "very slender and rather longer, extending considerably beyond the end ofthe 

orbital hoods" (Kemp, 1918: 273), the specimens do not match A. paludicola. The use of 

the terms "very slender" and "extending considerably" by Kemp are probably in comparison 

with the very short rostrum of A. paludicola s. str. specimens from Lake Chilka and are 

probably comparable to the rostra of A. cyanoteles or A. microrhynchus. The large-sized 

eggs (1.3 to 1.4 mm in diameter) are characteristic of A. paludicola and A. cyanoteles. The 

habitat of Tale Sap (where the specimens were collected) is slightly brackish, unlike that of 

the freshwater streams of Kota Tinggi where A. cyanoteles has been collected. The brackish 

habitat does agree with that of Lake Chilka from which A. paludicola has been obtained. 

This is further supported by the presence of Upogebia heterocheir, a brackish to marine 

water inhabitant (Kemp, 1915). In live colouration, the description given does not match 

either A. paludicola or A. cyanoteles but agrees well with the live colouration of A. 

microrhynchus which is also found from brackish waters (pers. observ.). The actual specimens 

(deposited in the Indian Museum) could not be obtained for examination in this present 

study. Based on the available information, four possible hypotheses on the identity of the 

Tale Sap specimens are put forward: these specimens could represent an extreme variant of 

A. paludicola or an extreme variant of A. cyanoteles or mistakenly identified A. microrhynchus 

or a new species. Unfortunately, the egg size of A. microrhynchus is not known. If it were, 

it might be useful in this case as a diagnostic character to either discount or include A. 

microrhynchus as a possible identity for the specimens. It is important however, that these 

original specimens be obtained and examined to determine their true identity. Until this is 

done, the specimens should tentatively be assigned to A. paludicola Kemp, 1915, and the 

distribution of the species should include Tale Sap in southern Thailand (see fig. 9). 

Johnson (1965, 1966) referred to a snapping shrimp from brackish to freshwaters from 

Malaya, specifically " ...in the Sedili basin of South Johore ..." (Johnson, 1965: 9) as A. 

paludicola (mis-spelled A. paludosus). One of Johnson's specimens from the above area 

labelled as A. paludosus (ZRC 1979.4415) was examined and has been confirmed to be a 

specimen of A. cyanoteles. In addition, the area mentioned above is also the type locality 

of A. cyanoteles. Therefore, Johnson (1965, 1966) was actually referring to A. cyanoteles. 

Alpheus cyanoteles can be differentiated fromA. euphrosyne and A. microrhynchus by: 

i) absence of a movable spine on the ischium of the third pereiopods (versus presence of 

spine); ii) different proportions in carpus of second pereiopod, 10:4:2:2:3 in A. cyanoteles 

versus 10:6:2:2:3 in A. euphrosyne (see Banner & Banner, 1966) and 10:3:1:1:2 in A. 

microrhynchus (see Banner & Banner, 1966). Other differences between A. cyanoteles and

A. euphrosyne include the presence of a distinctive transverse ridge running midway through 

the inner face of the palm of the large chela in A. cyanoteles (versus absence of such a 

ridge), the absence of a distal tooth on the inferior margin of merus of the large cheliped of 

the former (usually present in the latter) and the fact that the eggs of the former (1.5 mm in 

diameter) are much larger than those of the latter (0.5 mm in diameter). Alpheus cyanoteles 

can be further distinguished from A. microrhynchus by its generally smaller size. The largest 

A. cyanoteles specimen examined being an ovigerous female (ZRC 1996.58) of total length 

46.2 mm while the largest A. microrhynchus specimen examined was a female (ZRC 

1979.441) of total length 81.6 mm. In terms of habitat, A. cyanoteles differs from the two 

in that it is found (including ovigerous females) in true freshwater habitat while A. euphrosyne 

and A. microrhynchus inhagit brackish to oligohaline waters of estuarine and mangrove 

habitats. There are alfo differences in live colouration. The dark blue banding pattern of 

the abdomen together with the dark blue uropods and telson would clearly separate live 

specimens of A. cyanoteles from A. euphrosyne and A. microrhynchus. 

Fig. 8. Alpheus microrhynchus De Man, 1898. a, b, (ZRC 1979.441) (el28.1 mm, tl81.6 mm), Jurong 

prawn pond, Singapore. c, (ZRC 1992.8064) (el 11.9 mm, tl 33.8 mm), Sungei Buloh swamps, 

Singapore. Alpheus euphrosyne De Man, 1897. d, (ZRC 1979.438) (el 10.2 mm, tl 32.1 mm), Port 

Sweetenham (Port Klang), Selangor, Malaysia. a: inner face of right ftrst pereiopod; b: dorsal view 

of orbital hood and rostrum; c: dorsal view of orbital hood and rostrum; d: inner face of right ftrst 

pereiopod. Scales = 5.0 mm in a; 3.0 mm in b; 1.0 mm in c; 2.0 mm in d.

Distribution. - Alpheus cyanoteles has so far been recorded only from its type locality 

in the Kota Tinggi area, lohor, Peninsular Malaysia (see fig. 9). 

Fig. 9. Map showing distribution of Alpheus paludicola and A. cyanoteles .• : A. cyanoteles; 0: (?) 

A. paludicola; .: A. paludicola. 

Caridean freshwater shrimps are known almost exclusively from the families 

Palaemonidae and Atyidae. There are however, a small number of freshwater shrimps from 

the family Alpheidae in the genera Potamalpheops and Alpheus. Potamalpheops haugi 

(Coutiere, 1906) is found in the Niger Delta area and Gabon in West Africa, restricted to 

whitewater rivers above the tidal limit (Powell, 1979). Potamalpheops monodi (Sollaud, 

1932) is a tidal freshwater prawn found in a wide range of salinities, ranging from mesohaline 

to oligohaline to almost pure freshwater, in Cameroons, Senegal, Sierra Leone, and the Niger 

Delta in West Africa (Powell, 1979, 1976). Potamalpheops stygicola (Hobbs, 1973) is a 

troglobitic prawn found in freshwater caves in Oaxaca, Mexico (Hobbs, 1973, 1983). A 

fourth freshwater Potamalpheops shrimp is a new species found in freshwater forest streams 

in Singapore, Peninsular Malaysia and Indonesia [Pulau Bintan, Riau Archipelago] above 

the tidal limit (pers. observ.). Alpheus cyanoteles is only the fifth freshwater alpheid as well 

as the only true freshwater member of the genus Alpheus to be reported. Recent collections 

from acid water forest streams in Kota Tinggi, lohor [Peninsular Malaysia] over a period of 

12 months included several ovigerous females, thus providing an excellent sample size. This 

shows that the species, having established breeding populations in soft, acidic, true freshwater 

streams well above the tidal limits, can thrive in a wholly freshwater habitat. Very indicative 

of the nature of its habitat are the syntopic fish and decapod crustacean fauna collected (see 

Ecology section under Alpheus cyanoteles, new species) as well as the presence of the aquatic 

plants Cryptocoryne sp. and Blyxa sp. (pers. observ.). Alpheus cyanoteles is almost certainly 

able to complete its life cycle wholly in such freshwaters. This conclusion is based on the 

large series of A. cyanoteles specimens collected, which includes numerous ovigerous females 

and juveniles from the freshwater streams of Kota Tinggi, lohore. In addition , the large 

eggs, highly abbreviated larval development and benthic or non-pelagic larval behaviour

(pers. observ.) of the species are typical of many freshwater prawn species, for example, 

Macrobrachium pilimanus (De Man, 1879) (see Chong & Khoo, 1987). It is important 

however to note that A. cyanoteles has been reported to occur in oligohaline brackish waters 

as well (Johnson, 1965, 1966). However, the main point to note here is the fact that freshwater 

populations of this shrimp survive well, reproduce normally and most probably complete 

their development entirely in freshwater. 

Within the genus Alpheus, in addition to A. cyanoteles, A. paludicola Kemp, 1915, has 

also been reported from freshwaters (Kemp, 1915). However, it is more a brackish water 

species with high tolerance oflow salinity or even freshwater conditions that prevail seasonally 

in its habitat, that of a coastal lake with direct connection to the sea (Kemp, 1915), than a 

true freshwater prawn. Another brackish water species, A. microrhynchus De Man, 1897 

has been recorded frofu freshwaters in Thailand: "klongs or canals of Bangkok about 15 

miles from the river mouth where they are reported to be plentiful during the rainy season" 

(Banner & Banner, 1966: 135). These probably penetrated upstream during the rainy season 

from among the large numbers in the brackish waters of the river mouth and would seem 

unlikely to have established a breeding population there. It seems unlikely that A. 

microrhynchus can be a true freshwater prawn as it is known from this region primarily as 

a mangrove species inhabiting brackish and mangrove waters (Johnson, 1965, 1969; Tan & 

Ng, 1988; pers. observ.). Several other species of Alpheus besides A. paludicola and A. 

microrhynchus have been reported from estuaries, mangrove swamps or coastal lakes, 

tolerating waters of very low salinity or even seasonal fresh waters. One example is Alpheus 

pontederiae Rochebrune, 1883, from West Africa which has been reported from brackish 

waters (L.B.Holthuis, pers. comm.). From Southeast Asia, Banner & Banner (1966) report 

five alpheid shrimp species (all from the genus Alpheus) in addition to A. microrhynchus, as 

occurring in brackish waters, namely, Alpheus crassimanus, A. euphrosyne, A. malabaricus 

malabaricus, A. malabaricus songkla and A. rapax. However, A. euphrosyne is an obligate 

mangrove species while the rest are estuarine species and all are not known to penetrate 

freshwaters. 

KEY TO ALPHEUS SPECIES FOUND IN FRESHW ATERS AND 

MANGROVES OF SOUTHEAST ASIA 

1. Large chela without distinct transverse ridge running midway through inner face of palm, merus 

of first pereiopods usually with distal tooth on inferior margin ..... A. euphrosyne euphrosyne 

Large chela with distinct transverse ridge running midway through inner face of palm, merus of 

first pereiopods unarmed 2 

2. First article of carpus of second pereiopod proportionately long (carpus article ratio 10:3: 1:I :2); 

large species (tl up to 81.6 mm); found primarily in mangroves A. microrhynchus 

First article of carpus of second pereiopod proportionately shorter (carpus article ratio 10:4:2:2:3 

or 10:6:2:2:3); smaller species (tl not exceeding 46.2 mm); found in freshwater to brackish 

water but not in mangroves 3 

3. Rostrum short (reaching up to 0.2 of proximal segment of antennular peduncle) and broadly 

triangular in shape dorsally; ventrolateral tooth of bas icerite feebly developed and blunt or absent; 

large chela compact (ratio of chVchb 2.4), fingers robust (ratio of mfVmfb 1.1 to 1.3; ffUffb 2.6 

to 3.4); second pereiopod carpus article ratio 10:6:3:3:4; propodus of third pereiopod with 1 to 

3 ventral spines; appendix interna much longer than appendix masculina in males (ratio of aiV 

amI 1.7); movable lateral spine of uropodal exopod not flanked by fixed teeth; telson more 

slender and tapered in appearance (posterior margin width about 0.5 to 0.6 of anterior margin 

width); palp of first maxilliped unsegmented A. paludicola

Rostrum longer (reaching up to 0.3 to 0.5 of proximal segment of antennular peduncle) and slender, 

acutely tapering in shape dorsally; ventrolateral tooth of basicerite well-developed and acute; 

large chela more slender (ratio of chl/chb 2.5 to 3.0), fingers more slender (ratio ofmfllmfb 1.4 

to 2.0; ffl/ffb 3.4 to 4.1); second pereiopod carpus article ratio 10:4:2:2:3; propodus of third 

pereiopod with 6 to 8 ventral spines; appendix intema equal to or slightly longer than appendix 

masculina in males (ratio of ail/ami 1.0 to 1.3); movable lateral spine of uropodal exopod flanked 

medially and laterally by fixed teeth; telson broader and less tapered in appearance (posterior 

margin width about 0.6 to 0.8 of anterior margin width); palp of first maxilliped 2-segmented 

............................................................................................................ A. cyanoteles, new species 

Character 

Rostrum 

r Alpheus paludicola 

Very short (reaching up to 0.2 of 

proximal segment of antennular 

peduncle). 

Broadly triangular in shape dorsally. 

Antennular peduncle Intermediate segment almost equal 

to or slightly longer than proximal 

segment (ratio of isl/psl 1.1). 

Alpheus cyanoteles 

Relatively longer (reaching 0.3 to 0.5 

of proximal segment of antennular 

peduncle). 

Slender and acutely tapering shape 

dorsally. 

Intermediate segment distinctly longer 

than proximal segment (ratio of isl/psl 

1.3 to 2.0). 

If present, ventrolateral tooth is With well developed, acute, stout 

feebly developed and blunt. ventrolateral tooth. 

Scaphocerite with lateral margin Scaphocerite with lateral margin 

slightly concave. straight. 

Chela more compact (ratio of Chela more elongated (ratio of chl/chb 

chl/chb 2.4). 2.5 to 3.0). 

Fingers relatively shorter (ratio of Fingers relatively longer (ratio of mfl/ 

mflIchl 0.3 to 0.4; ffl/chl 0.4). chI 0.4 to 0.5; ffl/chl 0.4 to 0.5). 

Fingers more robust (ratio of Fingers more slender (ratio of mflImfb 

mfl/mfb 1.1 to 1.3; ffl/ffb 2.6 to 3.4). 1.4 to 2.0; ffl/ffb 3.4 to 4.1). 

First article of 5-segmented carpus 

shorter (carpus article ratio 

10:6:3:3:4). 

More slender, with relatively longer 

propodus (ratio of ml/pl 1.2). 

Propodus with 1 to 3 ventral spines. 

Appendix intema much longer than 

appendix masculina in males (ratio 

of ail/ami 1.7). 

Movable lateral spine of exopod not 

flanked by fixed teeth; distolateral 

angle of lateral margin 

subrectangular. 

More slender and tapered in 

appearance, with posterior margin 

width about 0.5 to 0.6 of anterior 

margin width. 

Palp unsegmented. 

First article of 5-segmented carpus 

more elongated (carpus article ratio 

10:4:2:2:3). 

More stout, with relatively shorter 

propodus (ratio of ml/pl 1.3 to 1.5). 

Propodus with 6 to 8 ventral spines. 

Appendix intema equal to or slightly 

longer than appendix masculina in 

males (ratio of ail/amI 1.0 to 1.3). 

Movable lateral spine of exopod 

flanked by short fixed tooth medially 

(projection of diaeresis) and laterally 

(projection of distolateral angle of 

lateral margin). 

Broader and less tapered in appearance, 

with posterior margin width about 0.6 

to 0.8 of anterior margin width.

The authors are grateful to Prof. L. B. Holthuis and Prof. F. A. Chace, Jr., for kindly 

reviewing the manuscript; Dr. A. J. Bruce for his assistance in reviewing the manuscript and 

in obtaining several key references; Mrs. C. M. Yang (ZRC) for access to material in the 

ZRC; and members of the Systematics and Ecology Laboratory, Department of Zoology, 

especially Tan Heok Hui and Tan Swee Hee for their help in countless ways. This study has 

been supported by research grant RP950326 to the second author from the National University 

of Singapore. This is contribution no. 96/11 from the Systematics & Ecology Laboratory, 

Department of Zoology, National University of Singapore. 

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series, 3: 1-168. 

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Nat. Hist., London, 21: 763-774. 

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Oaxaca, Mexico. Bull. Assoc. Mexican Cave Studies, 5: 73-80. 

Hobbs, H. H. Jr., 1983. The African shrimp genus Potamalpheops in Mexico (Decapoda, Alpheidae). 

Crustaceana, 44(2): 221-224. 

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Singapore (1967). STREMS II: 109-113. 

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(Decapoda, Caridea) from West Africa. Crustaceana, 31: 314-316. 

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Singapore, 14: 19t\-202. 

Received 28 Feb 1996 

Accepted 09 Apr 1996

a new species of freshwater snapping shrimp, alpheus cyanoteles

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