Kochimysis, Panampunnayil & Biju, 2007

Panampunnayil, S. U. & Biju, A., 2007, A new genus and species of Heteromysini (Crustacea- Mysidacea) from the backwater of Kochi (Kerala, India), Journal of Natural History 41 (29 - 32), pp. 1955-1963 : 1956-1957

Genus Kochimysis gen. nov.

Diagnosis

General form small and slender. Carapace broadly triangular in front. Eyes normal. Male lobe of antennule reduced to small setiferous lobe; antennal scale oval with rounded apex, setose all round, distal articulation absent. Second segment of mandibular palp broad; lacinia mobilis and molar processes well developed. Labrum rounded in front without any spines. Maxilla with segments of endopod subequal in length, second segment oval. Second thoracic limb with carpus and propodus segments in female simple, in male with notches on outer margin; third thoracic endopod not stouter; remaining endopods with carpus and propodus fused and divided into number of subsegments; pleopods rudimentary in both sexes; telson entire, apex with two pairs of spines, outer pair longer than inner. Uropods without spines. Females with marsupium formed of two pairs of lamellae.

Type species. Kochimysis pillaii .

Etymology

The genus is named after the locality, Kochi.

Remarks

According to the emended diagnosis of the tribe Heteromysini by Bowman and Orsi (1992), the diagnostic characters of the tribe are as follows: the male lobe of antennules usually reduced, antennal scale setose all round, carpus and propodus of thoracic limbs 4–8 fused and divided into subsegments, all pleopods rudimentary in both sexes, telson with or without apical cleft, and third thoracic endopod sometimes enlarged and robust. The new genus Kochimysis clearly belongs to the tribe Heteromysini based on these characters. The tribe at present contains 10 genera. In all the genera except Deltamysis Bowman and Orsi 1992 , some species of Pseudomysidetes Tattersall, 1936 , and Heteromysoides Bacescu, 1968 , the telson has an apical cleft. The new genus shows similarities to Deltamysis in the form and armature of the telson. However, the two genera are distinguished as follows: (1) in the new genus a small rounded setiferous male lobe is present on the third segment of the antennule, whereas in Deltamysis the lobe is not developed and the brush of setae are inserted directly on the ventral surface; (2) in the new genus the antennal scale does not have a distal articulation, whereas in Deltamysis the antennal scale has a transverse suture; (3) in the new genus both the mandibles have a lacinia mobilis and the second segment of the mandibular palp is broad. In Deltamysis the right mandible has no lacinia mobilis and the second segment of the mandibular palp is narrow; (4) in the new genus the endopodite segments of the maxilla are subequal in length and the distal segment is ovate. In Deltamysis the proximal segment is less than one-quarter of the distal segment and the latter is elongate and quadrangular.