The Mysidae (Crustacea: Peracarida: Mysida) in fresh and oligohaline waters of the Mediterranean. Taxonomy, biogeography, and bioinvasion Author Wittmann, Karl J. Author Ariani, Antonio P. Author Daneliya, Mikhail text Zootaxa 2016 4142 1 1 70 journal article 10.11646/zootaxa.4142.1.1 089dcc08-ba9c-4563-a6dc-d08cf2d83365 1175-5326 261102 FA423164-276C-44B0-A417-8E97AC3DF0AA Diamysis mesohalobia Ariani & Wittmann, 2000 Figs 14 , 15 Diagnosis (sensu lato: covering the three currently known subspecies). Appendix masculina 80–120% the length of terminal segment of antennular peduncle ( Fig. 14 B). Eyes normal; eyestalks with fenestra paracornealis weakly developed ( Fig. 15 K) or absent ( Fig. 15 A), in any case mostly not or poorly visible. Distal segment of maxillary palpus with 4–27 distinct denticles. Presence of fringes on male carapace varies between subspecies; no such fringes in females. Basal segment of thoracic exopods with outer corner spiniform or less frequently ending in an acute edge, occasionally rounded in the first and/or in some of the median and/or posterior exopods. All pereiopods with normal carpopropodus and slender, styliform claw ( Figs 14 E, 15B, M). Carpopropodus of thoracic endopods 3–8 with 3 (2; 4), 3–2 (4), 3–2, 2–3, 2–3 and 3–2 segments, respectively. Carpopropodus of endopod 3, if 3- segmented, with basal segment not longer than remaining segments combined ( Fig. 15 M). Thoracic endopod 3 and often also endopod 8 with at least one among the four paradactylar setae distally pectinate in (most) females, smooth or pectinate in males. Male pleopod 4 biramous with 2-segmented sympod and with small, 2-segmented endopod ( Figs 14 H, 15N); its exopod 2–(3)-segmented, with large modified seta at tip. This exopod with basal segment bearing a smaller smooth seta ( Figs 14 H, 15D), in certain populations occasionally with an additional barbed seta ( Fig. 15 N). Endopod of uropod with one strong spine below statocyst, statolith composed of vaterite. Telson subquadrangular ( Fig. 15 S) to subtriangular ( Fig. 15 J); maximum width is 1.4–3.0 times that at apex; its apical cleft with 8–39 laminae; cleft is 5–26% telson length. Taxonomy. Interbreeding experiments by Ariani & Wittmann (2000) indicated mutual crossability between morphologically different Mediterranean populations of D. mesohalobia . The three main morphotypes distinguished were, therefore, described at subspecific level as D. mesohalobia mesohalobia Ariani & Wittmann, 2000 , D. mesohalobia gracilipes Ariani & Wittmann, 2000 , and D. mesohalobia heterandra Ariani & Wittmann, 2000 ; each of these subspecies are treated in separate subchapters below. Occurrence ( Fig. 16 ). Marine, brackish and fresh (near)-coastal waters of the E-Mediterranean and Marmora Seas.