A world-wide review of species of the deepwater crangonid genus Parapontophilus Christoffersen, 1988 (Crustacea, Decapoda, Caridea), with descriptions of ten new species Author Komai, Tomoyuki Natural History Museum and Institute, Chiba, 955 - 2 Aoba-cho, Chuo-ku, Chiba 260 - 8682 (Japan) komai @ chiba-muse. or. jp text Zoosystema 2008 30 2 261 332 journal article 10.5281/zenodo.5393746 1638-9387 5393746 64CFDA2E-D606-4B3D-9A5B-E2FDF9B6974E Parapontophilus juxta n. sp. ( Figs 26 ; 27 ) TYPE MATERIAL . — Holotype : Western Indian Ocean Marion Dufresne , cruise MD 32 , stn DS 178, off Réunion Island , 21°03.6’S , 55°09.8’E , 412-460 m , 8.IX.1982 , ovig. ♀ 3.8 mm (MNHN-Na 16074a). Paratypes : western Indian Ocean. Marion Dufresne , cruise MD 32, stn DS 142, off Réunion Island , 20°50.3’S , 55°36.2’E , 480-675 m , 4.IX.1982 , 1 ♂ 3.6 mm , 10 ♀♀ 3.4-4.1 mm (MNHN-Na 16073). — Same data as holotype , 2♂♂ 3.0, 3.1 mm , 4 ♀♀ 2.5-3.6 mm (MNHN- Na 16074b). ETYMOLOGY. — The Latin juxta (= close) reflects the close similarity of this new species to other species of the Parapontophilus modumanuensis group. DISTRIBUTION. — Off Réunion Island , western Indian Ocean ( Fig. 36 ), 412- 675 m . DESCRIPTION Rostrum ( Fig. 26 A-C) narrow triangular in dorsal view, about 0.17-0.20 of carapace length, directed forward, straight, slightly falling short of distal margins of corneas, but overreaching tips of antennal teeth; lateral margins armed with 2 pairs of small teeth, anterior pair arising at about midlength of rostrum. Carapace ( Fig. 26A, B, D ) 1.40-1.50 times longer than wide; anterior epigastric tooth small, but conspicuous; posterior epigastric tooth moderately small, followed by weak middorsal ridge reaching beyond midlength of carapace; cardiac tooth absent; postorbital tooth very small; epibranchial tooth absent; epibranchial ridge obsolete or absent; branchiostegal tooth relatively small, falling short of dorsodistal margin of antennal basicerite. FIG. 26. — Parapontophilus juxta n. sp. , ovig. ♀ 3.8 mm, holotype, off Réunion Island, western Indian Ocean (MD 32, stn DS 178) (MNHN-Na 16704a): A , carapace and cephalic appendages,dorsal view; B , anterior part of carapace and eyes,dorsal view; C , rostrum dorsal view; D , anterior part of carapace, ophthalmic appendage and basal part of antennae, lateral view; E , third to sixth pleonal somites, lateral view; F , fourth to sixth pleonal somites, dorsal view; G , left antennal scale, dorsal view. Scale bars: A, B, D-F, 1 mm; C, G, 0.5 mm. Third pleonal somite ( Fig. 26E ) with moderately convex tergum and with moderately produced posterodorsal margin. Fifth somite ( Fig. 26E, F ) rounded dorsally. Sixth somite ( Fig. 26E, F ) 2.90-3.00 times longer than wide, 2.30-2.50 times longer than deep, about 2.30 times longer than fifth somite; dorsal surface rounded. FIG. 27. — Parapontophilus juxta n. sp. , ovig. ♀ 3.8 mm, holotype, off Réunion Island, western Indian Ocean (MD 32, stn DS 178) (MNHN-Na 16704a): A , left first pereopod, lateral view; B , same, subchela, ventral view; C , left second pereopod, lateral view; D , left fourth pereopod, lateral view. Scale bar: 1 mm. Eye ( Fig. 26A, B ) subpyriform; cornea pigment- ed with light yellowish brown; corneal surface distinctly faceted with moderately small lenses; maximal diameter of cornea 0.15-0.17 of carapace length; eye-stalk slightly constricted; ventromesial face without papilla-like projection. Antennular peduncle ( Fig. 26A ) reaching midlength of antennal scale. Antennal scale ( Fig. 26A, G ) 0.60-0.65 of carapace length and 2.90-3.20 times longer than wide; lateral margin nearly straight, lamella somewhat produced, distinctly overreaching distolateral tooth. Palm of first pereopod ( Fig. 27A, B ) 3.00-3.80 times longer than wide; pollex moderately small, width of palm including tip of pollex about 1.30 of width proximal to base of pollex; cutting edge moderately oblique; merus with relatively strong dorsodistal tooth. Second pereopod ( Fig. 27C ) relatively long for genus, overreaching midlength of merus of first pereopod. Fourth pereopod ( Fig. 27D ) overreaching distal margin of antennal scale by half to full length of dactylus; dactylus elongate, subspatulate, 0.85-0.95 of propodal length; carpus 0.55-0.65 of propodal length. Fifth pereopod similar to fourth, slightly falling short of distal margin of antennal scale. Appendix masculina of male second pleopod 0.85-0.90 length of appendix interna. Coloration in life Unknown. Size Males CL 3.0- 3.6 mm ; females CL 2.5-4.1 mm , ovigerous female CL 3.8 mm . REMARKS Parapontophilus juxta n. sp. appears closest to P. caledonicus n. sp. , as noted in the account of the latter species. It is also similar to P. demani and P.sibogae n. sp. , but it can be distinguished from the latter two species by the shorter branchiostegal tooth not reaching the dorsodistal margin of the antennal basicerite and the more elongate sixth pleonal somite (2.30-2.40 times as long as the fifth somite in P.juxta n. sp. versus 1.70-1.90 in P. demani and 2.20 in P.sibogae n. sp. ). Furthermore, the lateral rostral and the epigastric teeth are smaller in P. juxta n. sp. than in P. demani (cf. Figs 26C and 22D for the rostral teeth, Figs 26D and 22E for the anterior epigastric tooth). This new species, as well as P. psyllus n. sp. , is one of the smallest species in the genus.