Parapontophilus talismani ( Crosnier & Forest, 1973 )

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 : 289-292

Parapontophilus talismani ( Crosnier & Forest, 1973)

( Fig. 9 )

Pontophilus talismani Crosnier & Forest, 1973: 240 (key), 245, fig. 80a-d. — Dardeau & Heard 1983: 5, 27, figs 2e, 14. — de Saint Laurent 1985: 475. — Gore 1985: 270.

Pontophilus gracilis talismani – Chace 1984: 48 (key).

Parapontophilus talismani – d’Udekem d’Acoz 1999: 133.

TYPE MATERIAL. — Holotype: Off Mauritania. Talisman , stn 105, 16°38’N, 18°24’W, 3200 m, 18.VII.1883, ovig. ♀ 10.3 mm (MNHN-Na 1025).

Paratype: same data as holotype, 1 ovig. ♀ 9.7 mm (MNHN-Na 16226). Examined.

OTHER MATERIAL EXAMINED. — Caribbean Sea. USNS Bartlett, Cruise 1301-82, stn 93, Venezuela Basin, 13°32.30’N, 64°40.90’W, 3411-3459 m, 28.XI.1981, 1 ♀ 11.5 mm ( BMNH 1983-1984.59).

Northeastern Atlantic. W of Ireland, INCAL, stn CP 3, 56°38.0’N, 11°06.4’W, 2466 m, 17.VII.1976, 1 ♀ 13.0 mm (MNHN-Na 4320).

Bay of Biscay, BIOGAS 3, stn 2, CV 26, 47°33.9’N, 9°05.3’W, 2822 m, VIII.1973, 2 ♂♂ 9.4, 9.6 mm, 2 ovig. ♀♀ 9.0, 9.8 mm (MNHN-Na 4325).

BIOGAS 6, stn 2, CP 11, 47°30’N, 9°07.4’W, 3056 m, X.1974, 1 ♀ 11.1 mm (MNHN-Na 4328); 1 ♀ 10.3 mm (MNHN-Na 4329).— Stn 2, CP 12, 47°32.5’N, 9°11.6’W, 2925 m, X.1974, 1 ♀ 11.8 mm (MNHN-Na 4327).

POLYGAS, stn 2, CV 12, 47°32.5’N, 9°06.2’W, 2775 m, X.1972, 3 ovig. ♀♀ 9.0- 10.6 mm (MNHN-Na 4324). — Stn 18, 47°32.2’N, 08°44.9’W, 2138 m, X.1972, 1 ♀ 12.1 mm (MNHN-Na 4326). — EPI I, stn CH 38, 47°33.75’N, 08°42.15’W, 2100 m, 29.III.1984, 1 ♀ 9.0 mm (MNHN-Na 10521).

DISTRIBUTION. — Caribbean Sea and northeastern Atlantic from off Ireland to off Senegal ( Fig. 34 ), 2100-3459 m.

DESCRIPTION

Rostrum ( Fig. 9 A-D) narrow triangular in dorsal view, 0.10-0.15 of carapace length, directed forward and slightly curved ventrally, not reaching distal margins of corneas; dorsal surface shallowly concave in proximal half; lateral margins always armed with 1 pair of lateral teeth proximal to midlength. Carapace ( Fig. 9 A-D) 1.50-1.70 longer than wide, with 1 anterior epigastric tooth being subequal to or slightly smaller than posterior epigastric tooth; posterior epigastric and cardiac teeth moderately small for genus; postorbital tooth very small; postorbital and epibranchial ridges often clearly delimited; branchiostegal tooth nearly reaching dorsodistal margin of antennal basicerite.

Third pleonal somite with moderately convex tergum and moderately produced posterodorsal margin. Fifth somite smooth, rounded dorsally. Sixth somite ( Fig. 9E ) 3.50-3.80 times longer than wide, 3.00-3.20 times longer than deep; dorsal surface flat or with trace of median sulcus.

Eye ( Fig. 9D, F ) generally bean-shaped; cornea opaque or white in preservative, slightly elongate longitudinally; corneal surface not faceted, but white granules possibly representing remnants of lenses visible throughout integument of cornea; maximal diameter of cornea 0.17-0.20 of carapace length; boundary between cornea and eye-stalk obscure; no constriction near base of eye-stalk. Antennular peduncle ( Fig. 9A ) falling short of midlength of antennal scale. Antennal scale ( Fig. 9A ) 0.70-0.80 length of carapace, 4.00-4.50 times longer than wide; lateral margin slightly concave or nearly straight, distolateral tooth slightly falling short of or nearly reaching distal margin of lamella.

Palm of first pereopod ( Fig. 9G ) 3.20-3.50 times longer than wide; cutting edge moderately oblique; pollex relatively large, width of palm including tip of pollex 1.45-1.50 of width proximal to base of pollex; merus with relatively weak dorsodistal tooth. Fourth pereopod overreaching distal margin of antennal scale by half to full length of dactylus; dactylus subspatulate, 0.50-0.60 of propodal length; carpus 0.70-0.80 of propodal length. Fifth pereopod similar to fourth, slightly falling short of distal margin of antennal scale.

Coloration in life

Unknown.

Size

Males CL 9.4-9.6 mm; females CL 9.0- 13.0 mm, ovig. females CL 9.0- 10.3 mm.

REMARKS

The three abyssal species, Parapontophilus abyssi , P. occidentalis and P. talismani , are very similar to one another, and it is likely that they constitute a monophyletic assemblage. Shared characters include the anterior epigastric tooth being subequal to or slightly smaller than the posterior epigastric tooth and the non-faceted cornea of the eye. The morphology of the eyes is different for one another among the three species: the cornea is slightly elongate in P. talismani , rather nonelongate in the other two species; the boundary between the cornea and eye-stalk is not clearly delineated in P. abyssi and P. talismani , while it is distinct in P. occidentalis . The sixth pleonal somite is more slender in P. talismani than in P. abyssi and P. occidentalis (3.00-3.20 times longer than deep versus 2.60-2.90). The characters of the rostrum are also helpful in discriminating these three species, although varying in P. abyssi . The rostrum does not reach the anterior margins of the corneas in P. talismani and P. occidentalis , rather than usually reaching in P. abyssi . Parapontophilus talismani has always only one pair of lateral teeth on the rostrum, but P. abyssi and P. occidentalis have usually two pairs of lateral rostral teeth, though either pair is occasionally absent in the latter two species. The conspicuous postorbital and epibranchial ridges and the presence of a low dorsal plateau on the fifth pleonal somite separate P. occidentalis from P. abyssi and P. talismani . Parapontophilus cyrton n. sp. is similar to these three species in the non-faceted structure of the cornea, but as discussed in the Remarks of the latter species, it is characteristic in having the noticeably geniculate pleon.

Komai T.

Figures

FIG. 9.— Parapontophilus talismani (Crosnier & Forest,1973):A, carapace and cephalic appendages,dorsal view (setae partially omitted); B, carapace, lateral view; C, anterior part of carapace, cornea and basal part of antennae, lateral view; D, anterior part of carapace and eyes, dorsal view; E, sixth pleonal somite, lateral view; F, left eye, ventromesial view; G, subchela of right first pereopod, ventral view; A-E, G, ovig. ♀ 9.8 mm, Bay of Biscay (BIOGAS, stn CV 26) (MNHN-Na 4325); F, ovig. ♀ 9.0 mm, Bay of Biscay (POLYGAS, stn CV 12) (MNHN-Na 4324). Scale bars: A-E, G, 2 mm; F, 1 mm.

FIG. 34. — Geographic distribution of Parapontophilus abyssi (Smith, 1884) (■), P. gracilis (Smith, 1882) (●), P. occidentalis (Faxon, 1893) (◆) and P. talismani (Crosnier & Forest, 1973) (▲).