Aetobatus narinari (Euphrasen, 1790)

Brackish, Marine, Fishery

Exhibit ovoviparity (aplacental viviparity), with embryos feeding initially on yolk, then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus, fat or protein through specialised structures . Bears up to 4 young . Width at birth 17-35 cm . According to Uchida et al (1990) "quot;the male chases the female in mid water, then nibbles on her dorsal surface. The female stops swimming to begin copulation. The male bites the female on a pectoral fin and bends one clasper forward, then attempts an abdomen to abdomen copulation with either clasper, usually mid-water"quot; . Copulation lasted for 20 seconds to 1 minute .

Amphidromous. Refers to fishes that regularly migrate between freshwater and the sea (in both directions), but not for the purpose of breeding, as in anadromous and catadromous species. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.

Commonly found in shallow inshore waters such as bays and coral reefs but may cross oceanic basins . Benthopelagic, found near land at 1-60 m . Sometimes enters estuaries . Swims close to the surface, occasionally leaping out of the water, or close to the bottom . Frequently forming large schools during the non-breeding season . Feeds mainly on bivalves but also eats shrimps, crabs, octopus and worms, whelks, and small fishes . A carnivore .

Thaumatocotyle Infestation 3. Parasitic infestations (protozoa, worms, etc.) ;

Habitat reef-associated; amphidromous ; brackish; marine; depth range 1 - 80 m , usually 1 - ? m

Near Threatened (NT) IUCN 2006

fisheries: minor commercial; gamefish: yes; price category: medium; price reliability: very questionable: based on ex-vessel price for species in this family