Untersuchungen zur Lebensweise und Systematik von Leptomysis truncata und zwei verwandten Formen (Crustacea, Mysidacea)

In order to make systematics compatible with the results of field investigations on distribution, behaviour, and biology, revised diagnosis are given for Leptomysis buergii Bácescu, L. mediterránea Sars, and the revalidated L. truncata (Heller). Main diagnostic features are large rostrum and 11-14 setae at the distal joint of antennal scale in L. buergii; variable rostrum and 16-29 setae at distal joint of scale in L. mediterranea; and small rostrum and nods at branches of body chromatophores in L. truncata. The latter species occurs in three morphologically distinct forms: at Adriatic coasts L. truncata truncata (Heller), the only form with a seta at the basal joint of mandibular palp; in the West-Mediterranean, Tyrrhenian and Ionian Sea L. truncata sardica (Sars) with the telson evenly rounded; and in the Aegean and Black Sea L. truncatapontica (Czerniavsky) with the telson unevenly rounded. L. mediterranea is found in two morphogeographic variants: in the Mediterranean L. mediterranea mediterranea (Sars) without seta at the basal joint of mandibular palp; and in the European Atlantic L. mediterránea atlántica n. ssp. with 1-3 setae at this joint.