Itostenhelia, Karanovic & Kim, 2014

Karanovic, Tomislav & Kim, Kichoon, 2014, New insights into polyphyly of the harpacticoid genus Delavalia (Crustacea, Copepoda) through morphological and molecular study of an unprecedented diversity of sympatric species in a small South Korean bay, Zootaxa 3783 (1), pp. 1-96 : 53

Genus Itostenhelia gen. nov.

Type species. Itostenhelia polyhymnia sp. nov.

Other species. Stenhelia (Delavalia) golikovi Chislenko, 1978 .

Etymology. The new genus name is dedicated to late Dr. Itô Tatsunori, for his contribution to the taxonomy of harpacticoids in general, and stenheliin miraciids in particular. His last name is prefixed to the existing genus name Stenhelia .

Diagnosis. Habitus relatively slender in dorsal view, podoplean boundary between prosome and urosome conspicuous. Integument of all somites well sclerotized, prosomites generally smooth and urosomites covered with dense pattern of minute triangular spinules, no cuticular windows or pits. Hyaline fringe of all somites broad and smooth. Rostrum with dorsal transverse suture, bifid tip, pair of dorsal sensilla near tip, and bunch of strong anterior spinules; no dorsal pores. Genital double-somite completely fused along ventral surface but with deep suture indicating original segmentation between genital and third urosomites dorso-laterally, dividing doublesomite into shorter anterior and longer posterior parts; anterior part inflated, perfectly rounded laterally (in dorsal view), without sutures or folds; genital apertures placed ventro-laterally. Preanal somite without surface ornamentation, except for minute spinules. Anal somite cleft medially at posterior half, with wide and almost trilobate anal operculum, with pair of large dorsal sensilla on anal operculum, and posterior row of strong spinules on anal somite, without ventral spinules along medial cleft. Caudal rami cylindrical, from 3.5 to four times as long as wide, with several strong inner spinules in anterior third, and with seven setae (three lateral, one dorsal and three apical), all in posterior sixth of ramus length. Female antennula seven-segmented, but traces of ancestral division present on sixth segment, with distal posterior corner of first segment produced into short process, eighth segment with three lateral and two apical setae; no apical aesthetasc on ultimate segment. Male antennula strongly geniculate and nine-segmented, with additional large aesthetasc on third segment. Antenna composed of short coxa, strong allobasis with few cuticular sutures indicating ancestral segmentation, one-segmented endopod, and three-segmented exopod; endopod with two lateral spines flanking one slender seta. Mandibula without central seta on cutting edge, with six slender setae on small one-segmented endopod, and with two lateral and five apical setae on elongated and curved exopod; three apical exopodal setae strong and spiniform, one of them extremely long. Maxillula composed of praecoxa, coxa, basis, one-segmented endopod, and one-segmented exopod; endopod and exopod not confluent basally, with two and four setae respectively. Maxilla composed of large syncoxa, small basis and even smaller one-segmented endopod; three coxal endites armature formula (starting from dorsal side) 2.3.3; basis with two lateral slender setae and two apical geniculate spines; endopod with four slender setae. Maxilliped not prehensile, four-segmented, with armature formula 0.3.2.2. All swimming legs of similar size and long in comparison to body length, with sharp and long spiniform processes on intercoxal sclerites, spiniform process on inner distal corner of basis of second to fourth leg; all exopods three-segmented, endopod of first leg twosegmented, endopods of second to fourth legs three-segmented, except endopod of second leg in male, which with fused second and third segments and reduced and characteristically modified armature (apical armature consisting of outer spine with distal comb of spinules and two large spinules at midlength, and lateral spiniform seta significantly longer than spine); armature formula of exopods/endopods in female as follows: first leg, 0.1.022/ 1.211; second leg, 1.1.223/1.2.121; third leg, 1.1.322/1.1.321; fourth leg, 1.1.322/1.1.221; inner seta on first endopodal segments of second and third legs slender; distal inner setae on third exopodal and endopodal segments minute at least in third leg; sexual dimorphism only in second leg. Female fifth legs joined with small triangular intercoxal sclerite, with row of posterior spinules on baseoendopod at base of exopod; endopodal lobe with four setae, two inner ones significantly shorter than outer ones; exopod ovoid, more than twice as long as wide, with row of very long spinules along both inner and outer margins (outer ones especially long), with five setae; innermost exopodal seta longest and strongest, second and third exopodal seta from inner side short and slender, outermost seta hardly longer than neighbouring outer spinules. Male fifth leg with fused endopodal lobes forming slightly convex plate, with four spines (two belonging to each leg, very dissimilar in size, inner at least twice as long as outer), long posterior row of spinules between endopodal armature and exopod; exopod ovoid, with several outer spinules, with three inner setae (all short, slender, and smooth) and two apical spines, inner one fused basally to segment, outermost one strongest and longest. Female sixth leg minute, covering genital aperture, with single pinnate seta at outer distal corner, joined with opposite leg via deep ventral suture into single wide and short flap.