Oxidus gracilis - Greenhouse Millipede (C. L. Koch, 1847)

Diplopoda: Chilognatha: Helminthomorpha: Eugnatha: Merocheta: Polydesmida: Paradoxosomatidea: Paradoxosomatidae: Paradoxosomatinae: Sulciferini

VERSÃO EM PORTUGUÊS NO PROJECT NOAH: http://www.projectnoah.org/spottings/25488322
PICTURE OF THE IMMATURE IN JUNGLEDRAGON:

5th of April, 2018 at 11:43:34am.

Oxidus gracilis is a member of the class Diplopoda, subclass Chilognatha, infraclass Helminthomorpha, subterclass Eugnatha, superorder Merocheta, order Polydesmida, suborder Paradoxosomatidea, family Paradoxosomatidae, subfamily Paradoxosomatinae and tribe Sulciferini.

Oxidus gracilis is native to Japan but have been introduced globally. They can achieve lengths of 18-23mm. The dorsal section of each segment has a transverse groove with cream-colored legs. The segments are brown, but the borders are of a cream color. The adults dig tunnels in the soil, forming several chambers where they will lay their eggs after being impregnated. Females possess one more pair of legs compared to the males. Sexual maturity is achieved after 5-6 months in females, breeding season lasts all year and they lay egg batches of 40 to 300 sticky, white or brown eggs underground. The first instars of Oxidus gracilis are white in coloring, and proceed to grow more segments and legs and become darker as they age. Adults are thought to have a lifespan of one year. Analyses have identified six different noxious compounds they secrete in different quantities depending on their environment. These compounds include phenol and a cyanide derivative, and presumably are effective for defense from predation, and also for resisting colonization by bacteria and fungi in the soil.

Oxidus gracilis cannot bite through skin, so they are very passive and can't attack humans or animals. They feed on a wide amount of food sources, such as faeces, decaying vegetable matter, roots, fruits (decaying or fresh), rich soil, perhaps seeds and occasionally live plants when no other food is available. The adults and the immatures NEED a humid environment to live in as they are very prone to dehydration and dessication. Without constant water, they will shrivel and die very fast. Nocturnal, Oxidus gracilis often stay underground during the day or hidden below rocks, leaf litters or decaying wood. These hiding sources not only protect them from predators, but also conserve the needed humidity to keep them alive. During rain, they will come out of the ground to breath. They only have three defensive mechanisms against predation:

1 - Curling up. Due to their lack of speed and their inability to bite or sting, millipedes' primary defence mechanism is to curl into a tight coil – protecting their delicate legs inside an armoured exoskeleton.
2 - Releasing a foul odor.
3 - Hiding.

REPRODUCTIVE SYSTEM AND ANATOMY (Source - https://en.wikipedia.org/wiki/Millipede)

Millipedes breath through two pairs of spiracles located ventrally on each segment near the base of the legs. Each opens into an internal pouch, connecting to a system of tracheae. The heart runs the entire length of the body with an aorta stretching into the head. The excretory organs are two pairs of Malpighian tubules located near the mid-part of the gut. The digestive tract is a simple tube with two pairs of salivary glands to help digest food. The genital openings (gonopores) of both sexes are located on the underside of the third body segment (near the second pair of legs) and may be accompanied in the male by one or two penes, which deposit the spermatophores onto the gonopods. In the females, the genital pores open into paired small sacs called cyphopods or vulvae, which are covered by small hood-like lids and are used to store the sperm after copulation. Millipede sperm lack flagella, a unique trait among Myriapods.

REPRODUCTIVE SYSTEM AND ANATOMY ENDS HERE

Millipedes are preyed on by a wide range of animals, including various reptiles, amphibians, birds, mammals and insects, effectively establishing themselves in the food chain. Oxidus gracilis' importance in nature can be also be observed as natural decomposers, being detritivores.

Other sources:

https://en.wikipedia.org/wiki/Greenhouse_millipede

http://eol.org/pages/129182/details