Revision of Family Megacalanidae (Copepoda: Calanoida) Author Bradford-Grieve, Janet M. Author Blanco-Bercial, Leocadio Author Boxshall, Geoffrey A. text Zootaxa 2017 4229 1 1 183 journal article 37164 10.5281/zenodo.293480 07873971-1d73-4f3a-b361-179172ec47cf 1175-5326 293480 BCDF8F6F-B8B4-4A9D-A8B8-7EDCEF1100BE Elenacalanus tageae n. sp. ( Figs 94 , 101–106 ) Type locality. 26.441o N 139.037o E. Material examined. Antipode IV, IKMT: Stn 53D, 0–2500 m , 1♀ ( 13.4mm ) holotype, 1CV; Stn 55D, 0–2000 m , 1♂ ( 12.7 mm ) paratype. Type specimens. Deposited in the collection of the Scripps Institution of Oceanography , California : holotype female: PIC- 140409 -0015-HT; paratype male: PIC- 140409 -0016-PT. Morphological description. Following description based on holotype and paratype specimens from Antipode IV , Stns 53D and 55D. As for genus with following specific level features. Female ( Fig. 101 A–C). Total length 13.4 mm . Anterior margin of head in dorsal view with low projection dorsal to base of rostrum. In lateral view, posterior corners of pedigerous somite 5 rounded. Genital double-somite symmetrical in dorsal view, bulbous, about as long as wide, in lateral view bulging both ventrally and dorsally, and is much deeper than following somite. Antennule ( Figs 101 D, 102A–C) extending beyond caudal rami by at least 7 segments (segments XXI–XXVIII broken off). Lengths of segments (µm) as follows. Measurements taken along posterior border of each segment but two (posterior (shortest) and anterior) measurements taken of ancestral segment I. I (211, 603); II– IV (534); V (265); VI (294); VII (341); VIII (365); IX (380); X–XI (750); XII (632); XIII (711); XIV (917); XV (1125); XVI (1216); XVII (1262); XVIII (1309); XIX (1319); XX (1370); XXI (-); XXII (-); XXIII (-); XXIV (-); XXV (-); XXVI (-); XXVII (-); XXVIII (-). Segments I–V each with dorsal surface hair sensillum and adjacent macula cribrosa. Antenna ( Fig. 102 D) exopod ancestral segment IV with very short seta not extending beyond segment V. Maxillule ( Fig. 102 G) praecoxal arthrite with 13 setae including 2 on posterior surface and 1 longer and 1 smaller seta on anterior surface; coxal endite without setae, basal endites 1 and 2 with 2 setae each; endopod segments with 1, 1, 4+1 small anterior surface seta; basal exite with vestigial seta, epipodite with 7 long and 2 very small setae. Maxilliped (Fig. 103A) syncoxal endite 4 longest seta broken off — probably extending as far as distal basal seta as in male; endopod segments 2–6 with 4 subequal, 1, 1, 1 (no outer border seta but 1 macula cribrosa), 4 setae (2 large and 2 small, of which one on outer border), respectively. Leg 1 ( Fig. 101 E) exopod segment 3 proximal outer spine extends beyond base of terminal outer spine. Male ( Fig. 104 A–C). Anterior margin of head similar to that of female. Total length 10.8 mm . Urosomite II length 0.8 times its width in dorsal view; urosomite II is 1.5 times as long as urosomite III. In lateral view, posterior corners of pedigerous somite 5 rounded. Antennules ( Fig. 104 D, E) not entire; left antennule absent; right antennule first 16 ancestral segments remaining, ancestral segments IX–XI fused and XIV–XV fused on right. Antenna ( Fig. 105 A) exopod ancestral segments I–IV without setae. Mandible ( Fig. 105 B) basis with 4 (2 very small) inner setae. Maxillule ( Fig. 105 D, E) setation reduced in number and size relative to female: basal endites 1 and 2 with 2 and 1 reduced seta, respectively; endopod segments with 1 reduced, 1 reduced, 4+1 anterior surface seta; basal exite without seta, epipodite with 7 long setae. Maxilla ( Fig. 106 A, B) with longest setae extending only as far as anterior part of labrum. Maxilliped ( Fig. 106 C) similar to that of female; syncoxal endite 4, longest seta extending to distal basal seta. Legs 1–4 similar to those of female, especially exopod segment 3 of leg 1 which has proximal outer spine extending beyond base of distal outer spine. FIGURE 101. Elenacalanus tageae n. sp. female: A, dorsal view; B, lateral view; C, lateral view of rostrum; D, left antennule; E, posterior view of leg 1. Scale bar represents 1.0 mm on all figures. Illustrated specimen is from Antipode IV, Stn 53A, 0–2000 m. Leg 5 ( Fig. 106 D, E) slightly asymmetrical, left leg slightly longer than right leg; left exopod segment 2 inner distal corner bearing bifurcate specialised seta with 2 short setulose lashes arising from proximal part; inner border of exopod segment 3 naked on right, irregularly shaped and lined with setulues on left. Etymology. This species is named for Professor Tagea Björnberg the discoverer of the closely related species E. eltaninae . Distribution. Elenacalanus tageae is probably a bathypelagic species and has been taken only in the northwest Pacific Ocean 0–2500 m , south of Japan ( Fig. 94 , Table 1 ). Species comparison. The female of E. tageae is very like E. eltaninae differing only the longer proximal outer spine on leg 1 exopod segment 3 (extends beyond base of distal outer spine in E. tageae but short of this spine in E. eltaninae ) ( Table 11 ). The main difference between E. tageae and E. eltaninae is the nature of the male leg 5 left specialised seta on exopod segment 2: in E. tageae it is bifurcate with each short lash approximately equal in length while in E. eltaninae this seta is composed of a large rounded outer lobe and an elongate inner lash.