Crosniera dayrati, Ngoc-Ho, 2005

Ngoc-Ho, Nguyen, 2005, Thalassinidea (Crustacea, Decapoda) from French Polynesia, Zoosystema 27 (1), pp. 47-83 : 63

Crosniera dayrati n. sp.

( Figs 8 ; 9 )

TYPE MATERIAL. — Holotype: Marquesas Islands, Nuku Hiva, MUSORSTOM 9, Alis, stn 1306, 283- 448 m, 10.IX.1997, P. Bouchet, B. Dayrat, B. Richer de Forges coll.,, cl. 5 mm, tl. 15.5 mm ( MNHN Th 1418).

ETYMOLOGY. — The species is named for Benoît Dayrat, one of the collectors.

DISTRIBUTION. — Only known from the type locality. DIAGNOSIS. — Carapace with short acute triangular rostrum, slightly overreaching eyes, linea thalassinica extending posteriorly to level of cervical groove, latter present in median part. Telson longer than broad, tapering posteriorly.

Eyestalk short, not flattened, cornea terminal; A1 peduncle shorter than that of A2, A2 acicle very small; Mx2 scaphognathite with posterior seta; Mxp3 pediform, ischium with stiff setae on lower border and weak spinous mesial crest, merus with two lower spines.

P1 subequal, similar, unarmed except for fingers; merus with convex lower border; fixed finger of major P1 bearing large anteriorly directed tooth near midlength, fixed finger of minor P1 with small round teeth on proximal third.

Female Plp1 of two articles. Plp2-5 slender, with digiti-

Thalassinidea (Crustacea, Decapoda ) from French Polynesia elongate, with rounded posterior border; endopod presumably longer than telson with small spine on median carina.

DESCRIPTION

Carapace ( Fig. 8B ) with short acute triangular rostrum, slightly overreaching eyes; linea thalassinica extending posteriorly to level of cervical groove, latter present in median part; no anterolateral setal rows; posterodorsal margin excavate, continuous with posterolateral margin, latter with slight thickening.

Abdominal somite 1 ( Fig. 8A ) shorter than second, without anterolateral lobes, pleuron rounded ventrally; abdominal somite 2 weakly overlapping somite 1, pleuron with lower border nearly straight; abdominal somites 3-6 with convex lower border, somites 3-5 with fine lateral setae not arranged in rows. Telson ( Fig. 9H ), broken in holotype, presumably longer than broad, tapering posteriorly.

Eyestalk ( Fig. 8B ) short, not flattened, cornea terminal. A1 with article 1 overreaching eyestalk, article 2 shorter than article 3. A2 acicle very small, article 4 nearly three times as long as article 5. Mx2 ( Fig. 9A ) scaphognathite tapering posteriorly, with posterior seta (broken in figured appendage). Mxp1, 2 ( Fig. 9B, C ) as figured. Mxp3 ( Fig. 9D, E ) pediform with exopod slightly longer than ischium, latter with convex lower border carrying stiff setae and weak spinous mesial crest; merus with small lower spine near midlength and larger one distally; carpus, propodus, dactylus unarmed.

Figures

FIG. 8. — Crosniera dayrati n. sp., Marquesas, holotype, (MNHN Th 1418); A, lateral view; B, anterior part of carapace; C, D, minor

FIG. 9.— Crosniera dayrati n. sp.,Marquesas,holotype, (MNHN Th 1418); A, maxilla (posterior seta broken);B, C, maxilliped 1 and 2; D, E, maxilliped 3 and ischium in mesial view;F, pleopod 2;G, pleopod 3; H, telson (distal part missing) and uropods.Scale bars:1 mm.