Parapontophilus juxta, Komai, 2008

Komai, Tomoyuki, 2008, A world-wide review of species of the deepwater crangonid genus Parapontophilus Christoffersen, 1988 (Crustacea, Decapoda, Caridea), with descriptions of ten new species, Zoosystema 30 (2), pp. 261-332 : 316-319

publication ID	https://doi.org/ 10.5281/zenodo.5393746
publication LSID	lsid:zoobank.org:pub:64CFDA2E-D606-4B3D-9A5B-E2FDF9B6974E
persistent identifier	https://treatment.plazi.org/id/03AEC142-570F-FF86-4B77-FC2127738F58
treatment provided by	Marcus
scientific name	Parapontophilus juxta
status	sp. nov.

Treatment

Parapontophilus juxta n. sp.

( Figs 26 View FIG ; 27 View FIG )

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). GoogleMaps

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 View FIG ), 412- 675 m.

DESCRIPTION

Rostrum ( Fig. 26 View FIG 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 View FIG ) 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.

Third pleonal somite ( Fig. 26E View FIG ) with moderately convex tergum and with moderately produced posterodorsal margin. Fifth somite ( Fig. 26E, F View FIG ) rounded dorsally. Sixth somite ( Fig. 26E, F View FIG ) 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.

Eye ( Fig. 26A, B View FIG ) 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 View FIG ) reaching midlength of antennal scale. Antennal scale ( Fig. 26A, G View FIG ) 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 View FIG ) 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 View FIG ) relatively long for genus, overreaching midlength of merus of first pereopod. Fourth pereopod ( Fig. 27D View FIG ) 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 View FIG and 22D View FIG for the rostral teeth, Figs 26D View FIG and 22E View FIG for the anterior epigastric tooth). This new species, as well as P. psyllus n. sp., is one of the smallest species in the genus.