Onion powder as feed additive in Procambarus clarkii culture

Spermiogenesis in the Crayfish (procambarus Clarkii)

The sperm of the crayfish, Procambarus clarkii, is relatively simple among decapod sperm and was described in the first paper of this series (28). The present paper details the development of this sperm as followed with the light and electron microscopes. The process is divided into six stages for purposes of description. The main points of interest discussed are the absence of mitochondria or ...

Red Swamp Crayfish (procambarus Clarkii) in River Nile, Egypt

Crayfish (Procambarus clarkii) Effects on Lentic Lake Water Quality

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Dominance hierarchy formation in juvenile crayfish procambarus clarkii

The formation of social dominance hierarchies was studied in groups of five juvenile crayfish, 1.3-1.8 cm in length. Animals were grouped together in a small, featureless aquarium after having lived in isolation for more than a month. The occurrence of each of four behavior patterns ('attack', 'approach', 'retreat' and 'escape') was recorded for each animal, together with the frequency of encou...

Urine as a source of conspecific disturbance signals in the crayfish Procambarus clarkii.

Chemical signals are an important aspect of ecological interactions in crustacean systems. Repellent chemical signals can be classified into three context-specific categories: chemicals released directly from a repellent stimulus (avoidance chemicals), chemicals released from damaged conspecifics (alarm chemicals) and chemicals released from stressed but undamaged conspecifics (stress chemicals...

The crayfish Procambarus clarkii CRY shows daily and circadian variation.

The circadian rhythms of crayfish are entrained by blue light, through putative extra retinal photoreceptors. We investigated the presence and daily variation of CRY, a protein photosensitive to blue light spectra and ubiquitous in animals and plants, in the putative pacemakers of Procambarus clarkii, namely the eyestalk and brain, at different times of the 24 h light:dark cycles. Using differe...