Wellstenhelia euterpe, 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 : 47-52

publication ID	https://doi.org/ 10.11646/zootaxa.3783.1.1
publication LSID	lsid:zoobank.org:pub:E6155BDC-AEAE-475D-BC83-61B3B863344C
DOI	https://doi.org/10.5281/zenodo.4910574
persistent identifier	https://treatment.plazi.org/id/6878D460-FF80-FFE0-64D0-FACA031DF8F1
treatment provided by	Felipe
scientific name	Wellstenhelia euterpe
status	sp. nov.

Treatment

Wellstenhelia euterpe sp. nov.

( Figs. 30–33 View FIGURE 30 View FIGURE 31 View FIGURE 32 View FIGURE 33 )

Type locality. South Korea, South Sea , Gwangyang Bay, sampling station 2, muddy sediments, 34.881861°N 127.635083°E ( Fig. 1 View FIGURE 1 ) GoogleMaps .

Specimens examined. Female holotype dissected on one slide (collection number NIBRIV0000232689), female paratype mounted on SEM stub (collection number NIBRIV0000232690), type locality, 39 July 2012, leg. K. Kim.

Etymology. The species is named after Euterpe (Ancient Greek: Eύτέρπη), one of nine Muses from Greek mythology, who was a patron of lyric poetry and song. The species name is a noun in apposition (in the nominative case).

Description. Female (based on holotype and one paratype). Body length 460 µm and 373 µm respectively. Integument thick and surface smooth, without minute pits. Body segmentation, colour, nauplius eye, and hyaline fringes as in Wellstenhelia calliope sp. nov. Most somite ornamentation also similar to Wellstenhelia calliope , and presumed homologous pore and sensilla numbered with same Arabic numerals (see Figs. 30A, B View FIGURE 30 , 31A, B, C, D, E View FIGURE 31 , 32A View FIGURE 32 ) to allow easier comparison. Habitus ( Figs. 30A, B View FIGURE 30 , 33A View FIGURE 33 ) more robust, with prosome/urosome length ratio 1.3, body length/width ratio about three, cephalothorax twice as wide as genital double-somite.

Rostrum ( Fig. 30A, C View FIGURE 30 ) similar in shape and ornamentation to Wellstenhelia calliope but dorsal pore no. 2 position much more anterior (arrowed in Fig. 30C View FIGURE 30 ) and rostrum larger in comparison to cephalothorax.

Cephalothorax ( Figs. 30A, B View FIGURE 30 , 31A, B View FIGURE 31 , 33B View FIGURE 33 ) about 0.85 times as long as wide; comprising 28% of total body length. Surface of cephalothoracic shield with 34 paired or unpaired sensilla and pores, most of which probably homologous to those in Wellstenhelia calliope (indicated with Arabic numerals in illustrations), but 12 pores and sensilla missing (nos. 4, 6, 7, 10, 14, 16, 19, 21, 33, 34, 35, 37, 39); absolute and relative positions of some pores and sensilla differ and posterior dorsal sensilla no. 40 paired; six unique pores and sensilla indicated with geometric shapes in Fig. 31A, B View FIGURE 31 .

Pleuron of second pedigerous somite ( Figs. 31C View FIGURE 31 , 33C View FIGURE 33 ) ornamented as in Wellstenhelia calliope , except lateral pair of sensilla no. 48 and anterior pair of pores no. 43 missing.

Pleuron of third pedigerous somite ( Figs. 31D View FIGURE 31 , 33C View FIGURE 33 ) ornamented as in Wellstenhelia calliope , except anterior pair of pores no. 51 more widely spaced.

Pleuron of fourth pedigerous somite ( Figs. 31E View FIGURE 31 , 33C View FIGURE 33 ) ornamented as in Wellstenhelia calliope , except anterior lateral pair of pores no. 57 missing.

First urosomite ( Fig. 30A, B View FIGURE 30 ) as in Wellstenhelia calliope , except pores nos. 63 & 67 missing.

Genital double-somite ( Figs. 30A, B View FIGURE 30 , 32A View FIGURE 32 , 33D View FIGURE 33 ) as in Wellstenhelia calliope , except much more slender, with dorsal pair of sensilla no. 69 more widely spaced, anterior pore no. 68 missing, and shorter ventral row of spinules (arrowed in Fig. 32A View FIGURE 32 ).

Last three urosomites ( Figs. 30A, B View FIGURE 30 , 32A View FIGURE 32 ) as in Wellstenhelia calliope , except for shorter ventral row of spinules (arrowed in Fig. 32A View FIGURE 32 ) and more closely spaced sensilla pair no. 77 on first of them, as well as somewhat stronger spinules in anal sinus.

Caudal rami ( Figs. 30A, B View FIGURE 30 , 32A, B View FIGURE 32 , 33E View FIGURE 33 ) short and stout, much shorter than in Wellstenhelia calliope (arrowed in Figs. 30A, B View FIGURE 30 , 32A, B View FIGURE 32 ), about as long as anal somite, cylindrical, 1.7 times as long as wide (ventral view), parallel, with space between them about one ramus width; most ornamentation and all armature as in Wellstenhelia calliope , except both ventral pores (nos. 82, 83) missing.

Antennula ( Figs. 31F View FIGURE 31 , 33F View FIGURE 33 ) ornamentation and armature as in Wellstenhelia calliope , except first segment with more spinules in distal row and sixth segment proportionately shorter (arrowed in Fig. 31F View FIGURE 31 ).

Antenna ( Fig. 30D, E View FIGURE 30 ), labrum, and paragnaths as in Wellstenhelia calliope .

Mandibula ( Fig. 30F View FIGURE 30 ) as in Wellstenhelia calliope , except with larger spinules on basis (arrowed in Fig. 30F View FIGURE 30 ) and additional row of spinules on coxa (arrowed in Fig. 30F View FIGURE 30 ).

Maxillula, maxilla ( Fig. 30G View FIGURE 30 ), and maxilliped ( Fig. 30H View FIGURE 30 ) as in Wellstenhelia calliope , except maxilliped with row of long and slender spinules on coxa (arrowed in Fig. 30H View FIGURE 30 ).

Swimming legs ( Fig. 32C, D, E, F, G View FIGURE 32 ) segmentation, most ornamentation, most armature, and proportions of various armature elements as in Wellstenhelia calliope , except all legs without anterior pore on first endopodal segment, first leg without inner spinules on coxa (arrowed in Fig. 32C View FIGURE 32 ), second leg with proximal row of spinules on coxa slightly longer (arrowed in Fig. 32E View FIGURE 32 ) and with additional inner seta on third endopodal segment (arrowed in Fig. 32F View FIGURE 32 ), and fourth leg with distal inner seta on third endopodal segment less spiniform (arrowed in Fig. 32G View FIGURE 32 ).

Fifth leg ( Figs. 30B View FIGURE 30 , 31G View FIGURE 31 , 32A View FIGURE 32 , 33D View FIGURE 33 ) segmentation, general shape, and most armature and ornamentation as in Wellstenhelia calliope , except innermost endopodal seta missing (arrowed in Figs. 30B View FIGURE 30 , 31G View FIGURE 31 , 32A View FIGURE 32 ), two additional rows of anterior spinules of basis (arrowed in Fig. 31G View FIGURE 31 ), and endopodal lobe without spiniform process at base on exopod (arrowed in Fig. 31G View FIGURE 31 ). Length ratio of endopodal setae, starting from inner side, 1: 1.2: 0.85. Length ratio of exopodal setae, starting from inner side, 1: 0.5: 0.3: 0.85: 0.8: 0.5.

Sixth leg as in Wellstenhelia calliope .

Male. Unknown.

Variability. Only two females were studied and no variable morphological feature was observed.

Morphological affinities. Wellstenhelia euterpe sp. nov. differs from all congeners by the armature of the female fifth leg endopod, which bears only three setae ( Fig. 31G View FIGURE 31 ). The complete reduction of the innermost element is considered here a clear autapomorphy. Other unique features of this species include two inner setae on the third endopodal segment of the second swimming leg ( Fig. 32F View FIGURE 32 ) and slender distal inner seta on the third endopodal segment of the fourth swimming leg ( Fig. 32G View FIGURE 32 ), but these are plesiomorphic character states in a larger group of stenheliins. Compared to other congeners, Wellstenhelia euterpe has the smallest body, shortest caudal rami ( Fig. 32A, B View FIGURE 32 ), shortest sixth antennular segment ( Fig. 31F View FIGURE 31 ), and smoothest and thickest cuticulum. It also has a unique position of the dorsal rostral pore ( Fig. 30C View FIGURE 30 ), which is much more anterior than in other congeners, but the state of this character is unknown in Wellstenhelia bocqueti ( Soyer, 1971) comb. nov., Wellstenhelia hanstromi ( Lang, 1948) comb. nov., and Wellstenhelia melpomene sp. nov. (see Lang 1948; Soyer 1971; Kornev & Chertoprud 2008). Other unique features include position and/or presence of several pores and sensilla on somites ( Figs. 30A, B View FIGURE 30 , 31A, B, C, D, E View FIGURE 31 ), size of spinules on the mandibula ( Fig. 30F View FIGURE 30 ) and maxilliped ( Fig. 30H View FIGURE 30 ), and presence of two rows of large spinules on the basal part of the female fifth leg baseoendopod ( Fig. 31G View FIGURE 31 ). Quite clearly this species has no close relatives among recent congeners. Unfortunately, the males are still unknown.