Epifauna on freshwater crayfish (Crustacea: Decapoda) in Croatia

Istraživanje epifaune slatkovodnih rakova kao bazibionata provedeno je tijekom proljetnoljetnog razdoblja 2014. i 2015. godine. Fauna je prikupljena s pet slatkovodnih vrsta rakova (Decapoda): tri autohtone vrste (Astacus astacus, Austropotamobius pallipes, Austropotamobius torrentium) i dvije alohtone vrste (Pacifastacus leniusculus, Procambarus fallax f. virginalis). Ciljevi ovog rada bili su: (i) analizirati sve skupine epifaune na slatkovodnim rakovima reda Decapoda, (ii) usporediti epifaunu rakova s faunom okolnog sedimenta i perifitona, (iii) usporediti epifaunu pojedinih vrsta rakova, posebno autohtonih i alohtonih. Zabilježeno je 44 različitih svojti epifaune od čega je brojnošču prevladavala skupina Ciliophora s vrstom Vorticella campanula i rodom Epistylis. Skupina Rotifera zabilježena je kao najraznolikija, a najbrojnije vrste bile su Lepadella parasitica i Dicranophorus hauerianus. Predstavnici branhiobdela potvrđeni su kao epibionti rakova te je po prvi put na području Hrvatske zabilježena sjevernoamerička vrsta Xirogiton victoriensis. Od ostalih skupina zabilježene su: Catenulida, Gastrotricha, Nematoda, Bivalvia, Hirudinea, Tardigrada, Crustacea, Hydrachnidia i Chironomidae. Rezultati NMDS i klaster analize pokazali su razdvajanje epifaune pojedinih vrsta rakova; epifauna alohtonih i autohtonih vrsta rakova je odvojena, a isto tako postoji razdvajanje epifaune između autohtonih vrsta rakova. Rezultati statističke analize ukazuju da postoji značajna razlika između epifaune rakova i faune sedimenta i obraštaja. S obzirom na rezultate, može se zaključiti da je epifauna rakova specifična te se razlikuje između pojednih bazibionata.The research of epifauna on freshwater crayfish as basibionts was conducted during springsummer 2014. and 2015. Epizoic community was examined from five different crayfish: three autochtonous species Astacus astacus, Austropotamobius pallipes, A. torrentium and two introduced, invasive species Pacifastacus leniusculus and Procambarus fallax f. viriginalis. The aims of this research were: (i) to analyze epizoic community living on freshwater crayfish, (ii) to compare epifauna living on crayfish with surrounding fauna living on sediment and periphyton, (iii) to compare epifauna between crayfish species, especially between autochthonous and allochthonous species. The results of statistical analysis indicated a significant difference between epifauna and fauna of sediment and periphyton. 44 different taxa of epifauna was recorded. The most abundant group was Ciliophora with most common species Vorticella campanula and Epistylis sp. The most diverse group was Rotifera with most common species Lepadella parasitica and Dicranophorus hauerianus. Branchiobdellidanas were confiremd as common crayfish epibionts and for the first time nort american species Xirogiton victoriensis has been recored in Croatia. Catenulida, Gastrotricha, Nematoda, Bivalvia, Hirudinea, Tardigrada, Crustacea, Hydrachnidia and Chironomidae were also recorded living on freshwater crayfish. Results of NMDS and Cluster analyses showed the eparation of epifauna from autochotnous and allochthonous crayfish and also the separation of epifauna between autochthonous species. Results of statistical analyses showed significant difference between epifauna and fauna of sediment and periphyton. It can be concluded that the whole epizoic community composition established on a particular crayfish is species-specific and can be different between basibiont species