Comparative Investigations On the Systematics and Taxonomy of European Maja Species (Decapoda, Brachyura, Majidae)

Abstract

The systematic validity of the differentiation between the two European spider crabs Maja crispata Risso, 1827 and Maja squinado (Herbst, 1788) is clarified. The intra- and interspecific variability of morphological characters is examined in juvenile and adult specimens and the results are discussed. Due to ontogenetic changes there is neither a single, constant morphological character nor a constant character combination which allows a complete separation of all postlarval stages of the two species. The best diagnostic characters are the median dorsal carapace spine row combined with a spine located at the basal antennal joint. Multivariate analyses of morphometric characters offered for the first time appropiate quantitative methods for a complete separation of adults and an almost complete separation of juveniles of the two species which have not been available previously.