Distribution and evidence of co-infection of the two microsporidian parasites and in complex in Northern and Central Italy.

complex is an endangered freshwater crayfish species in Europe and the assessment of the health status of its wild populations is essential for conservation purposes. The two microsporidia and have been reported to cause in complex a chronic parasitic infection, known as ‘porcelain disease’, which reduces population fitness and leads the host to death. Due to the similar macroscopic signs produced, molecular biology analyses are required to unambiguously distinguish between these microsporidia.

Diet and trophic niche of the invasive signal crayfish in the first invaded Italian stream ecosystem.

The occurrence of the signal crayfish Pacifastacus leniusculus in the Valla Stream was the first established population of this invasive species recorded in an Italian stream ecosystem. We evaluated the seasonality of diet and trophic niche of invasive signal crayfish in order to estimate the ecological role and effects on native communities of the stream ecosystem. We studied the differences in food source use between sexes, life stages and seasons using carbon and nitrogen stable isotope analyses.

Color variation in signal crayfish .

External coloration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the color expression, the mechanisms of color perception, and the general mechanisms controlling color evolution and function. Among all, camouflages from predators and conspicuousness are of particular interest because pose animal to choose between opposite adjustment in coloration. The external coloration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer, and the trade-off between camouflage and communication had led to a variety of responses, involving signal partitioning, spectral sensibility, changing coloration, or signaling behavior.

Ultrastructural and molecular characterization of Vairimorpha austropotamobii sp. nov. (Microsporidia: Burenellidae) and Thelohania contejeani (Microsporidia: Thelohaniidae), two parasites of the white-clawed crayfish, Austropotamobius pallipes complex (Decapoda: Astacidae).

The microsporidiosis of the endangered white-clawed crayfish Austropotamobius pallipes complex has generally been attributed to only one species, Thelohania contejeani, the agent of porcelain disease. Species identification was mostly assessed by macroscopic examination or microscopic evaluation of muscle samples rather than by molecular or ultrastructural analyses. A survey conducted on A.

Female freshwater crayfish adjust egg and clutch size in relation to multiple male traits.

Females may invest more in reproduction if they acquire mates of high phenotypic quality, because offspring sired by preferred partners may be fitter than offspring sired by non-preferred ones. In this study, we tested the differential maternal allocation hypothesis in the freshwater crayfish, Austropotamobius italicus, by means of a pairing experiment aimed at evaluating the effects of specific male traits (body size, chelae size and chelae asymmetry) on female primary reproductive effort. Our results showed that females laid larger but fewer eggs for relatively small-sized, large-clawed males, and smaller but more numerous eggs for relatively large-sized, small-clawed males.