engleski

Morphological diversity of the stone crayfish (Austropotamobius torrentium) in Croatia

The stone crayfish (Austropotamobius torrentium) is one of four native European crayfish species inhabiting Croatian freshwater ecosystems. It is distributed at higher altitudes, in smaller waterbodies of both the Black Sea and Adriatic Sea basins. In the last few decades, noticeable declines of stone crayfish populations have been recorded across its distribution range in Europe. Losses are mainly caused by anthropogenic pressure onto stone crayfish habitats, presence and spread of non-native invasive crayfish species, and climate changes. Therefore, stone crayfish is considered a threatened species, protected by national and international legislation. Effective protection of existing populations requires development of conservation and management plans based on the sound knowledge of species, including information on genetics and morphology. Recent molecular-phylogenetic studies of A. torrentium discovered the existence of at least seven divergent monophyletic phylogroups within the species, with the highest genetic variability recorded in the Dinaric region in Croatia. Also, previous preliminary analyses of morphometric features of a few stone crayfish populations indicated their significant differences. This study aimed to test if some morphological characteristics separate among phylogroups. For this purpose 245 stone crayfish, belonging to 5 phylogroups, were analysed through traditional and, for the first time, geometric morphometric analyses. Traditional multivariate discriminant analyses included 24 morphometric features per crayfish, while geometric morphometrics comprised analyses of 22 landmarks on the dorsal side of cephalothorax. Both methods revealed congruent results, and significant differences among phylogroups in analysed morphometric features were obtained. Applications of acquired results in the future A. torrentium conservation programs are discussed.

traditional MDA, geometric morfometry

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