Chronic toxicity bioassay and effect of endosulfan, HCH, copper and zinc on the survival and intermoult duration of larvae of mangrove crab Macrophthalmus erato De Man.

The effects of insecticides (endosulfan, HCH) and heavy metals (copper and zinc) were studied on survival and duration of the moult cycle of larvae and megalopa of a common mangrove crab, Macrophthalmus erato, that inhabits Pitchavaram mangroves, southeast coast of India. In chronic toxicity test, percentage of survival from hatchling to megalopa stage at different concentrations of endosulfan (0.048 to 0.

Effect of feed on larvae of Macrobrachium malcolmsonii (H. Milne Edwards) reared in synthetic brackishwater.

Freshwater prawn, Macrobrachium malcolmsonii, has potential for aquaculture. Larvae of M. malcolmsonii were reared in synthetic brackishwater using commercial salts.

The composition and nature of cuticular proteins in parasitic copepods.

1. The protein components of the cuticle of the two parasitic copepods Pennella elegans and Caligus savala were studied electrophoretically and histochemically. 2.

Occurrence of resilin and its significance in the cuticle of Pennella elegans, a copepod parasite.

The cuticle of the region connecting the anterior and posterior half of the body of parasite shows two peculiarities. The epicuticle is folded and the lamellations in the outer region of the procuticle are wavy. Histochemical tests and investigations with fluorescent compounds showed that there is evidence of stabilization of the cuticle protein by formation of di- and trityrosine links as reported in the wing ligament cuticle of insects and elastic leg-hinge of the crayfish.