TWO NEW SPECIES OF DEEP-WATER CAPRELLA (PERACARIDA, AMPHIPODA, CAPRELLIDAE) FROM THE PACIFIC COAST OF MEXICO COLLECTED DURING THE TALUD XIV CRUISE, WITH A CHECKLIST OF SPECIES OF CAPRELLIDAE RECORDED FOR THE EASTERN PACIFIC

摘要

Two new deep-water species of the genus Caprella are described from the central Gulf of California, Pacific coast of Mexico. Caprella calderoni new species is distinguished from the 32 previously recorded species of Caprella from the eastern Pacific by its smooth forehead and pereonites, body not particularly slender, gnathopod 2 inserted at about mid-length of the second pereonite, elongated gills and gnathopod 1, the relative length of antenna 2 articles, length of the flagellum of antenna 1, the lack of an antero-lateral projection on pereonites 2 and 3, and the length-height proportion of pereonite 1. It is close to C. striata Mayer, 1903, recorded from Alaska. Caprella striata, however, features a different number of articles in the antenna 1 flagellum, two latero-posterior spines on pereonites 6, a small dorsal tubercle on pereonites 5 and 6, and a poison spine on the propodus of gnathopod 2 (all lacking in the new species). The buccal appendages also present significant differences. Caprella mercedesae new species, belongs to a group of eastern Pacific species with a sharp spine on the forehead. It is distinguished from all these species by a combination of characters, including the general shape of the body (not robust), the insertion level of gnathopod 2, its general shape, and the relative length of its dactylus, the relative length of antennae 1 and 2, the shape and relative length of the gills, the proportionally shorter or longer pereonites, and the presence of dorsal tubercles on at least pereonites 5-7 (absent in the new species).