Willenstenhelia terpsichore, 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 : 85

Willenstenhelia terpsichore sp. nov.

Synonymy. Stenhelia (Delavalia) minuta A. Scott – Marinov & Apostolov 1981: p. 66, pl. I, figs. 1–9.

Type locality. Slovenia, Adriatic Sea , Piran, muddy bottom, 15 m depth, approximate coordinates 45.5387°N 13.539°E.

Type material. Hollotype female as illustrated by Marinov & Apostolov (1981) in figs. 1, 2, 3, 7, 9, dissected on a slide; female paratype as illustrated by Marinov & Apostolov (1981) in fig. 4, dissected on a slide; male allotype as illustrated by Marinov & Apostolov (1981) in figs. 5, 6, 8, dissected on a slide; all collected on 7 August 1971, originally deposited at the the Institut de Pêche, Varna, Bulgaria, but since then lost (Dr. Apostol Apostolov pers. comm.); not examined.

Etymology. The species is named after Terpsichore (Ancient Greek: Τερψιχόρη), one of nine Muses from Greek mythology, who was a patron of dance. The species name is a noun in apposition (in the nominative case).

Description. Female as described by Marinov & Apostolov (1981) from Slovenia, and illustrated in thier figures 1, 2, 3, 4, 7 and 9 as Stenhelia (Delavalia) minuta A. Scott, 1902 . Male as described by by Marinov & Apostolov (1981) from Slovenia, and illustrated in thier figures 5, 6 and 8 as Stenhelia (Delavalia) minuta A. Scott, 1902 .

Remarks. Marinov & Apostolov (1981) were aware that their two female specimens from Slovenia differed from those of Willenstenhelia minuta (A. Scott, 1902) comb. nov. in the relative length of the caudal rami (with the length/width index of four). However, they considered that to be a case of intraspecific variability, assuming that their specimens occupy an intermediate position between the typical W. minuta from the Indian Ocean and Suez Canal (with the l/w index of three) and those reported by Por (1964) from the Mediterranean Coast of Israel (with the l/w index of five). As a further evidence of the extreme variability of this supposedly widely distributed species they mentioned and illustrated armature of the female second leg endopod, with or without an inner seta on the third segment. As males were not recorded in the Indian Ocean, Suez or Israeli populations, their characters naturally could not be compared.

In our view, and in light of the newly discovered diversity of the Korean sympatric stenheliins, these morphological differences cannot be attributed to intraspecific variability. Thus we name this Adriatic population reported by Marinov & Apostolov (1981) as Willenstenhelia tepsichore sp. nov. Although the caudal rami length of this species has an intermediate value, its geographic position is not intermediate, which means that we are not dealing with a cline. As mentioned above, it would seem that its closest relatives are Willenstenhelia minuta and Willenstenhelia urania sp. nov., but all three species are known from a very limited set of morphological characters and they would need to be redescribed in detail if we are to assess their phylogenetic relationships. In addition to the differences in the length/width ratio of the caudal rami, there are also some differences in the shape of the female fifth leg, as well as in the proportions of different armature elements on this appendage, at least as far as can be judged from their published drawings. Affinities and differences between Willenstenhelia tepsichore and Willenstenhelia thalia sp. nov. are discussed in the affinities section of the latter species, and they both differ from the Mozambique Willenstenhelia unisetosa ( Wells, 1967) comb. nov. by much longer caudal rami.