Morphometrical characteristics of noble crayfish (Astacus astacus (Linneaus, 1758)) in the North Croatia

Rakovi su poznati kao važna sastavnica biološke raznolikosti u rijekama, jezerima i močvarama s važnom ekološkom ulogom u funkcioniranju vodenih ekosustava te važnom ulogom u hranidbenim mrežama. Podred Astacidea dijeli se na tri porodice koje se međusobno razlikuju po morfološkim, biološkim i ekološkim značajkama. Na području Europe obitava pet autohtonih vrsta rakova iz porodice Astacidae. Danas su slatkovodne autohtone vrste rakova iznimno ugrožene regulacijom vodenih tokova, velikom količinom otpadnih tvari u vodenim ekosustavima, unesenim invazivnim vrstama te bolestima poput račje kuge koja je unesena s invazivnim američkim vrstama rakova. Prema provedenim istraživanjima u Hrvatskoj su zabilježene četiri autohtone vrste iz dva roda; Austropotamobius pallipes, Austropotamobius torrentium, Astacus astacus i Astacus leptodactylus. Cilj ovog istraživanja je bio istražiti morfometrijske značajke vrste A. astacus te utvrditi razlikuju li se geografski udaljene populacije sjeverne Hrvatske u mjerenim morfometrijskim parametrima. U slučaju utvrđivanja značajnih razlika između populacija, cilj je bio izdvojiti one koje najviše doprinose diskriminaciji jedinki. Dobiveni podaci će poslužiti kao baza za daljnja istraživanja ove vrste u Hrvatskoj.Crayfish are known as an important component of biodiversity in rivers, lakes and wetlands with an important ecological roles in food webs and in the functioning of aquatic ecosystems. The Astacidea are subdivided into three families that differ in morphological, biological and ecological features. In Europe, five indigenous species of crayfish from the Astacidae family are described. Today, freshwater autochthonous crayfish species are endangered due to watercourse regulations, large amounts of wastes in aquatic ecosystems, imported invasive crayfish species, and diseases such as crayfish plague which was introduced to Europe with invasive American crayfish species. According to research conducted in Croatia, four indigenous species from two genera have been recorded; Austropotamobius pallipes, Austropotamobius torrentium, Astacus astacus and Astacus leptodactylus. The aim of this study was to investigate the morphometric characteristics of the A. astacus and to determine whether the geographically distant Northern Croatian populations differ in measured morphometric parameters. In the case of significant differences in measured morphometric parameters among populations, the aim was to identify those that contribute the most to the discrimination of individuals. The results obtained through this research will serve as a basis for further research of this vulnerable crayfish species in Croatia