Ž . Methyl farnesoate MF , the predominant juvenile hormone-like compound of crustaceans, was found in the hemolymph of female Cherax quadricarinatus crayfish. Administration of MF to C. quadricarinatus females during their winter reproductive arrest period had no effect on reproduction; however, it did have a tendency to accelerate molting. However, since MF caused increased Ž . mortality ;47%...

A quantitative enzyme-linked immunosorbent assay (ELISA) was developed to monitor the onset of secondary vitellogenesis in Cherax quadricarinatus females and in intersex individuals (having both male and female reproductive systems) after removal of the androgenic gland (AG). As a prerequisite for the assay, the 106-kDa polypeptide was separated from newly laid C. quadricarinatus eggs by SDS-PA...

Crayfish farmers reported reduced tolerance of stress in specimens of Cherax quadricarinatus, which were formerly robust crayfish. Furthermore, one farmer reported a large reduction in yield with final harvest only equaling the stocking weight. Upon trapping, one-third of the crayfish regularly died overnight and a further one-third died on the sorting tray during sexing of juveniles (approxima...

Abstract The first molecular evidence for natural, in ovo, vertical transmission of Chequa iflavirus and Athtab bunyavirus from farmed female redclaw crayfish (Cherax quadricarinatus) cultured northern Queensland, Australia is presented. Cherax reovirus was also examined, but that this spread via ovo vertically very limited. Amongst 57 broodstock-derived pools fertilized eggs, 38 (66.7%), 34 (5...

In crustaceans, molting is known to be under the control of neuropeptide hormones synthesized and secreted from the eyestalk ganglia. While the role of molt-inhibiting hormone (MIH) in regulating molting has been described in several species using classical methods, an in vivo specific MIH targeted manipulation has not been described yet. In the present study, an MIH cDNA was isolated and seque...

The pH and salinity balance mechanisms of crayfish are controlled by a set of transport-related genes. We identified a set of the genes from the gill transcriptome from a freshwater crayfish Cherax quadricarinatus using the Illumina NGS-sequencing technology. We identified and characterized carbonic anhydrase (CA) genes and some other key genes involved in systematic acid-base balance and osmot...

Carbonated hydroxyapatite is the mineral found in vertebrate bones and teeth, whereas invertebrates utilize calcium carbonate in their mineralized organs. In particular, stable amorphous calcium carbonate is found in many crustaceans. Here we report on an unusual, crystalline enamel-like apatite layer found in the mandibles of the arthropod Cherax quadricarinatus (freshwater crayfish). Despite ...