Changes in hemolymph glucose, hepatopancreas glycogen, total carbohydrates, phosphorylase and amino transferases of sumithion-stressed freshwater rice-field crab (Oziotelphusa senex senex)

Adult crabs were exposed to 3 concentrations of sumithion with a control group over a 20-day period. Hemolymph glucose levels were monitored in each group over the course of the experiment. The group demonstrating the most acute and sustained hyperglycemia (2 ppm sumithion) was then analyzed, as also the controls for changes in hepatopancreas glycogen, total carbohydrates, phosphorylase and aminotransferases. Significant (P less than 0.001) depressions in hepatopancreas glycogen and total carbohydrates and elevations of phosphorylase and transaminases were observed in sumithion-stressed crabs when compared with controls. These changes are discussed with respect to gluconeogenesis and possible influences of hyperglycemic hormone, which is released into hemolymph of stressed crab.

Effect of sumithion on ovarian growth of a fresh water rice field crab (Oziotelphusa senex senex Fabricius)

Sumithion exposure resulted in a decrease in the ovarian growth of the intact female crab, Oziotelphusa senex senex Fabricius apparently by the release of the gonad-inhibiting hormone (GIH).

In vivo acute physiological stress induced by BHC on hemolymph biochemistry of Oziotelphusa senex senex, the Indian rice field crab

Indian rice field crabs, exposed to a lethal concentration (LC50/24 h = 39 mg/l) of benzene hexachloride (BHC) to study acute toxic effects, showed changes in hemolymph glucose and protein. The effect of BHC resulted in hyperglycemia and hyperproteinemia.

Roles of 5-hydroxytryptamine and dopamine as neurotransmitters eliciting release of erythrophorotropic hormones in the fiddler crab, UCA pugilator

This article reviews the endocrinological, pharmacological and biochemical evidence ascribing neurotransmitter roles for 5-hydroxytryptamine (5-HT, serotonin) in eliciting the release of red pigment-dispersing hormone (RPDH) and for dopamine (DA) in stimulating the release of red pigment-concentrating hormone (RPCH) in the fiddler crab, Uca pugilator. 5-HT produces red pigment dispersion in intact crabs, but only indirectly. Likewise, DA evokes red pigment concentration in vivo but it has no effect on red chromatophores (erythrophores) in isolated legs. The data obtained with 5-HT and DA agonists and antagonists on red pigment translocation in vivo and in vitro, are consistent with their neurotransmitter candidacies in evoking the release of these erythrophorotropic hormones.

Hyperglycemia in the fresh water field crab (Oziotelphusa senex senex) produced by a pesticide (BHC)

Hyperglycemia, Oziotelphusa senex senex, Hyperglycemic Hormone, Hexachlorocyclohexane (BHC) Benzene hexachloride (1,2,3,4,5,6-hexachlorocyclohe-xane) (BHC) produced a significant increase in the hemolymph sugar level of intact crabs. Oziotelphusa senex senex, apparantly by triggering release of the hypergly­ cemic hormone (HGH).

[Effects of injections of ecdysterone on the molt and regeneration in the crab Carcinus maenas (L.)]

Two successives injections of 10 microng/g of ecdysterone induce precocious ecdysis in 66% of Crabs. This induction of precocious ecdysis is always accompanied by an inhibiting effect on regeneration: tiny abnormal regenerates or none are obtained. A majority of recipients of ecdysterone underwent successful ecdysis. Experimental results are discussed; a morphological and cytological study of ecdysterone effects on regeneration is announced.

Neurohemal organ extracts effect the ventilation oscillator in crustaceans

Extracts of the pericardial organs of crabs injected into intact animals cause an increase in the frequency of scaphognathite beating. The active factor is not dopamine of 5-hydroxytryptamine, which are present in pericardial organs; it is probably a peptide. The factor may represent a hormonal mechanism of coordinating heart rate and ventilation.

Limulus chromatophorotropin: action on isolated Uca legs and in various crustaceans

Limulus CNS chromatophorotropin causes melanin dispersion in isolated legs of Uca. Theophylline potentiation of extract activity suggests that the material may act through the adenylate cyclase-cAMP system. The extracts are also active on the chromatophores of 7 decapod species from 6 families.