The experiment was conducted to investigate the effects of artemia enriched with lipid emulsions containing highly unsaturated fatty acids on growth and survival of juvenile freshwater crayfish Astacus leptodactylus. Juvenile crayfish were fed artemia enriched with commercial emulsions (red pepper and olio ω3) and un-enriched artemia (control). The highest eicosapentaenoic acid (EPA) level was ...

The aim of this research was to study the occurrence of Vibrio spp., Aeromonas hydrophila, Escherichia coli and Campylobacter spp. in crayfish from Azerbaijan Province using culture method and PCR assay. A total of 55 isolates were collected from 97 studied samples. Vibrio spp., A. hydrophila, E. coli and Campylobacter spp. were detected in 26 samples (26.8%), 12 samples (12.3%), 15 samples (15...

Using pairings of male crayfish Procambarus clarkii with a 3-7% difference in size, we confirmed that physically larger crayfish were more likely to win encounters (winning probability of over 80%). Despite a physical disadvantage, small winners of the first pairings were more likely to win their subsequent conflicts with larger naive animals (winning probability was about 70%). By contrast, th...

Biologists and policy makers continue to seek environmental correlates of mercury bioavailability in aquatic ecosystems. In this study, we assessed the effects of drainage basin, habitat type, size class, and sex on mercury concentrations in the northern crayfish, Orconectes virilis (Hagen). Drainage basin, habitat type, and size class had significant effects on mercury concentration in crayfis...

We tested the hypothesis that polarization sensitivity enhances the detection of moving, transparent objects by examining the escape response of the red swamp crayfish (Procambarus clarkii Girard) from a visual threat. A transparent, birefringent target trans-illuminated by either partially linear polarized or unpolarized light was advanced toward individual crayfish. The optical axis of the ta...

Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the "tens rule" which states that only a minority of species introduced to new regions become established, and only a minority of those beco...

Discrepancies exist among spectral measurements of sensitivity of crayfish photoreceptors, their absorption in situ, and the number and absorption spectra of crayfish photopigments that are extracted by digitonin solutions. We have determined the photosensitivity spectrum ofcrayfish rhodopsin in isolated rhabdoms using long wavelength fluorescence emission from crayfish metarhodopsin as an intr...

BACKGROUND Invasive predators may change the structure of invaded communities through predation and competition with native species. In Europe, the invasive signal crayfish Pacifastacus leniusculus is excluding the native white clawed crayfish Austropotamobius pallipes. METHODOLOGY AND PRINCIPAL FINDINGS This study compared the predatory functional responses and prey choice of native and inva...

To evaluate the accumulation of aluminium, cadmium, chromium, copper, lead, mercury, nickel, and zinc in crayfish and fish organ tissues, specimens from three drinking water reservoirs (Boskovice, Landštejn, and Nová Říše) and one contaminated site (Darkovské moře) in the Czech Republic were examined. Crayfish hepatopancreas was confirmed to be the primary accumulating site for the majority of ...