Two new deep-sea species of Argestidae and Ameiridae (Copepoda: Harpacticoida) from the Eastern Mexican Pacific and Gulf of California, with proposal of a new genus of the family Argestidae

摘要

A handful of benthic harpacticoid species are known from the Gulf of California. Here I describe Argestes analongises sp. n. (Argestidae), and Argestigens celibis sp. n. (Ameiridae) from the deep sea of the Tropical Eastern Pacific and Gulf of California. Argestes analongises sp. n. fits in the subfamily Argestinae (Argestidae) and was attributed to the genus Argestes by the presence of small spinules covering the body surface of, at least, the urosome, and by the presence of an extremely elongated distal seta on the sixth segment of the female antennule. This new species seems to be allied to A. angolaensis by the situation of all the caudal setae, and by the ventral position of caudal seta III. They differ in the relative length of the female caudal rami, size, shape and relative position of the sensilla-bearing tubercles associated to the anal somite, armature of the mandibular basis, shape of the exopodal and endopodal segments of swimming legs, and relative length of the setae on the female P5 endopodal lobe and position of the innermost seta of the exopod of the female fifth leg. Argestigens celibis sp. n. was attributed to the family Ameiridae based on the non-argestid maxilla, on the presence of a more or less well-developed endopodal lobe of the male fifth leg and three inner setae on the third endopodal segment of the third leg, and on the presence of the typically modified ameirid-like inner spine on the basis of the male first leg. The new species was attributed to Argestigens based on the non-prehensile endopod of first leg and presence of long inner spinules on the basis of second to fourth legs. Additionally, a new genus, Georgus gen. n., is proposed for Bodinia peterrumi, and some comments are given on the monophyly of that genus.