Michelopagurus tangaloa, Lemaitre, 2015

Lemaitre, Rafael, 2015, A new species of the hermit crab genus Michelopagurus McLaughlin, 1997 (Crustacea: Decapoda: Paguridae) from Moorea, French Polynesia, Zoosystema 37 (2), pp. 363-370 : 364-367

Michelopagurus tangaloa n. sp.

( Figs 1-4 )

TYPE MATERIAL. — Holotype: Moorea , French Polynesia, ♂ 2.7 mm, sta DW3461, 17°27’S, 149°49’W, 844-877 m, 19.X.2009 ( MNHN IU-2013-5647 ex UF23537 ).

Paratypes: Moorea , French Polynesia, sta DW3459, 17°28’S, 149°48’W, 485-560 m, 19.X.2009: 1 ♂ 2.5 mm, in scaphopod shell ( UF23534 ) ; sta DW3460, 17°28’S, 149°50’W, 660-680 m, 19.X.2009: 1 ♀ 3.1 mm ( USNM 1253315 ex UF 23526 ) ; sta DW3462, 17°27’S, 149°50’W, 1000-1145 m, 19.X.2009: 1 ov ♀ 2.1 mm, in scaphopod shell ( UF23504 ) .

ETYMOLOGY. — The specific name is given using one of the names of the Polynesian creator-god or god of the sea, who made himself a wife by carving her from stone, and after throwing the spare fragments of stone into the primordial ocean, these became the islands of the Pacific.

DISTRIBUTION. — So far known only from the South Pacific, in Moorea, Society Islands, in French Polynesia; depth: 485-1145 m.

DESCRIPTION

Shield ( Fig. 1A )

About as broad as long; anterolateral margins sloping; posterior margin truncate; dorsal surface smooth and glabrous, or with scattered short tufts of setae, weakly calcified medially. Rostrum acutely triangular, reaching slightly beyond tip of lateral projections, with small terminal spine. Lateral projections triangular, terminating sharply or bluntly. Posterior carapace with lateral lobes slender, fused to shield.

Ocular peduncles

Short and stout, less than half (including corneas) length of shield, dorsal surface with scattered short tufts of setae; corneas not dilated, as wide as distal width of ocular peduncle. Ocular acicles triangular, terminating bluntly and with strong submarginal spine; separated basally by about 0.8 basal width of 1 acicle.

Antennular peduncles

Overreaching ocular peduncles (including corneas) by full length of ultimate peduncular segment. Ultimate segment with tufts of short setae dorsodistally and scattered setae elsewhere. Penultimate segment glabrous. Basal segment with acute spine on dorsolateral margin. Flagellum long, about as long as combined length of ultimate and penultimate peduncular segments; ventral flagellum usually with seven articles.

Antennal peduncle ( Fig. 1B )

Overreaching ocular peduncles (including corneas) by full length of fifth peduncular segment. Fifth and fourth segments with scattered short setae. Third segment with strong spine at ventrodistal margin. Second segment with dorsolateral distal angle produced, terminating in strong bifid spine minutely serrated dorsally; dorsomesial distal angle with small sharp spine. First segment with small spine on laterodistal margin and one on ventrodistal margin. Antennal acicle long, weakly curved outward and reaching to distal half of fifth peduncular

Figures

FIG. 1. — Michelopagurus tangaloa n. sp., holotype ♂ 2.7 mm,Moorea,French Polynesia (MNHN IU-2013-5647 ex UF23537):A, shield and cephalic appendages, dorsal view; B, left antennal peduncle, lateral view; C, basis and ischium with crista dentata of left third maxilliped, inner view; D, sternite XII (of third pereopods), ventral view; E, sternite XIV and coxae of fifth pereopods with sexual tubes, ventral view; F, telson, dorsal view. Scale bars: A, 1 mm; B-F, 0.5 mm.

FIG. 2. — Michelopagurus tangaloa n. sp., holotype ♂ 2.7 mm, Moorea, French Polynesia (MNHN IU–2013–5647 ex UF23537), chelipeds: A, right, dorsal view; B, left, dorsal view; C, D, carpus and chela of same in lateral (C) and mesial (D) views. Scale bar: 1 mm.

FIG. 3. — Michelopagurus tangaloa n. sp., holotype ♂ 2.7 mm, Moorea, French Polynesia (MNHN IU–2013–5647 ex UF23537): A, right second pereopod, lateral view; B, dactyl of same, mesial view; C, right third pereopod, lateral view; D, dactyl of same, mesial view; E, propodus and dactyl of left fourth pereopod, lateral view. Scale bars: A-D, 1 mm; E, 0.5 mm.

FIG. 4. — Michelopagurus tangaloa n. sp., 1 ♀ 3.1 mm, Moorea, French Polynesia (USNM 1253315 ex UF 23526),freshly collected specimen removed from housing, dorsal view.