Elenacalanus sverdrupi ( Johnson, 1958 ) Johnson, 1958

Bradford-Grieve, Janet M., Blanco-Bercial, Leocadio & Boxshall, Geoffrey A., 2017, Revision of Family Megacalanidae (Copepoda: Calanoida), Zootaxa 4229 (1), pp. 1-183 : 151-153

Elenacalanus sverdrupi ( Johnson, 1958) new combination

( Figs 94 , 107 )

Bathycalanus sverdrupi Johnson, 1958 , pp 257–265, figs 1–14 Bathycalanus sverdrupi: Grice & Hulsemann 1967 , p. 13.

Type locality. 12.550o N, 164.817o E.

Material examined. Holotype examined USNM 101078. Additional records from Smithsonian Institution, USNM numbers: 259717, 272745–46.

Morphological description. As for genus with following specific level features.

Female. Total length 16.8–17.0 mm. Anterior margin of head in lateral view projecting forwards and in dorsal view rostral branches partially visible. In lateral view posterior corners of pedigerous somite 5 rounded. Genital double-somite swollen, symmetrical in dorsal view, much wider than long.

Antennule not extending to caudal rami. Antennule not mounted on holotype slide so not checked.

Antenna exopod ancestral segment IV bearing short seta extending to segment VIII.

Mandible basis with 3 setae ( Johnson 1958).

Maxillule ( Fig. 107 A, B) praecoxal arthrite with 14 setae including 3 setae on posterior surface and 1 moderately long seta on anterior surface; coxal endite without setae, basal endites 1 and 2 with 2 and 1 seta respectively; endopod segments with 1, 1, 4+1 small setae; basal exite without seta, epipodite with 7 long and 2 very short, reduced setae.

Maxilla with terminal setae curled distally in semicircle and extending beyond rostrum, setae on coxal endite 2 particularly well developed, curled in semicircle and of similar length to terminal setae.

Maxilliped syncoxa endite 4 longest seta extending beyond distal border of endopod segment 2; endopod segments 3–6 with 1, 1, 1, 2, respectively, apparently without any outer border setae on endopod segments 5 and 6. [after Johnson 1958 —limb not on slide therefore not checked]

Leg 1 ( Fig. 107 C) exopod segment 3 with 2 outer border spines, proximal spine broken on mounted leg and probably longer than that illustrated by Johnson (1958).

Male. Unknown.

Distribution. Elenacalanus sverdrupi is an upper abyssopelagic species known only from the tropical west Pacific from a tow at 2103 m ( Johnson 1958), the Indian Ocean at 275–2080 m ( Grice & Hulsemann 1967) and the Gulf of Guinea ( Owre & Foyo 1967) ( Fig. 94 , Table 1 ).

Species comparisons. Elenacalanus sverdrupi is very like other members of this genus, nevertheless, it is distinguished by: the short bluntly tapering rostral points directed slightly anteriorly, the very short antennules not extending beyond the caudal rami, the single seta on the maxillule second basal endite, and the unusually long curled setae on maxilla coxal endite 2 ( Table 11 ).

Figures

FIGURE 94. Distribution of Elenacalanus nom. nov. species: filled triangle = Elenacalanus princeps; open trangle = E. eltaninae; open square = E. tageae n. sp.; filled square = E. sverdrupi; open circle = E. inflatus.

FIGURE 107. Elenacalanus sverdrupi (Johnson, 1958) female: A, maxillule, posterior surface; B, maxillule praecoxal arthrite, anterior surface; C, leg 1 anterior surface. Scale bars represent 1.0 mm on figure C; 0.1 mm on figures A, B. Illustrated specimen from type specimen USNM 101078.