ECOLOGICAL AND MORPHOLOGICAL CHARACTERISTICS OF THE DANUBE CRAYFISH PONTASTACUS LEPTODACTYLUS (ESCHSCHOLTZ, 1823) FROM THE MATURA RIVER (BOSNIA AND HERZEGOVINA)
DOI:
https://doi.org/10.7251/ASB240501037RAbstract
Danube crayfish, one of the native European crayfish species, is on decline in many parts of its range. The Sava River and its tributaries are under increased pressure from invasive crayfish spreading. Providing data on resident native crayfish species is thus of utmost importance for their better conservation and protection. The population of Pontastacus leptodactylus (Eschscholtz, 1823) from a small tributary of the Sava River, The Matura River, has been investigated from May to August 2021. Our research encompassed a sample of 54 adult P. leptodactylus specimens (31 males and 23 females). Crayfish were sampled, measured and released unharmed. A standardized set of 12 morphometric parameters as well as body weight were taken. Positive correlation was found between body length and weight (♂ R2=0.9111; ♀ R2=0.9116), body weight and claws length (♂ R2=0.8923; ♀ R2=0.9596), as well as carapace width and body length (♂ R2=0.9761; ♀ R2=0.8838). Pronounced sexual dimorphism regarding most of the measured parameters was confirmed. Fulton's condition factor and the Crayfish constant both indicate males are in better fitness, which is in line with the results of previous research in Europe. Apart from crayfish data, the main physical and chemical parameters of the habitat and present aquatic macroinvertebrates community were measured as complementary data. Moderate level of organic pollution is present, with N and P (nitrogen and phosphorus) being the main threats, mostly due to intensive agriculture in the area. The macroinvertebrates community consists of 14 identified taxa, with gastropods as the most diverse and abundant group (57%). Crustaceans (Amphipoda and Isopoda) are the subdominant group in terms of relative abundance (30%). The recorded macroinvertebrate community indicates moderate organic pollution, and it is quite typical for similar watercourses in the region.
