Parapontophilus cornutus, Komai, 2008
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publication ID |
https://doi.org/ 10.5281/zenodo.5393746 |
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publication LSID |
lsid:zoobank.org:pub:64CFDA2E-D606-4B3D-9A5B-E2FDF9B6974E |
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persistent identifier |
https://treatment.plazi.org/id/03AEC142-5727-FF9E-48B1-FB19246D883E |
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treatment provided by |
Marcus |
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scientific name |
Parapontophilus cornutus |
| status |
sp. nov. |
Parapontophilus cornutus n. sp. ( Figs 10-12 View FIG View FIG View FIG ; 35 View FIG )
TYPE MATERIAL. — Holotype: Austral Islands . BENTHAUS, stn CP 1965, Tubuai Island, 23°21.3’S, 149°33.9’W, 500-1200 m, 19.XI.2002, ♀ 9.7 mm (MNHN-Na 16159). GoogleMaps
Paratypes: BENTHAUS, same data as holotype, 1 ♂ 8.0 mm (MNHN-Na 16160). — Stn CP 1966, 23°21.3’S, 149°34’W, 636-1200 m, 19.XI.2002, 1 ♀ 7.6 mm (MNHN-Na 16161).
ETYMOLOGY. — From the Latin cornutus , meaning horn, in reference to the characteristic horn-like rostrum of the new species.
DISTRIBUTION. — So far known only from the Austral Islands in French Polynesia ( Fig. 35 View FIG ). Actual bathymetric range of this new species remains unclear, as the present specimens were collected from very steep slopes ranging from 500 to 1200 m.
DESCRIPTION
Rostrum( Figs 11C View FIG ; 12A, B View FIG )slender,elongate subconical, 0.25-0.40 of carapace length, somewhat directed upward, distinctly overreaching distal margins of corneas; lateral margins with 2 pairs of minute teeth closely appressed to rostrum.Carapace ( Figs10 View FIG ; 11A, B View FIG ; 12 View FIG ) about 1.50 times longer than wide; anterior epigastric tooth absent; posterior epigastric and cardiac teeth moderately small; postorbital tooth absent; postorbital ridge very low,obsolete;epibranchial ridge low, but well-marked; branchiostegal tooth relatively strong, reaching or slightly overreaching dorsodistal margin of antennal basicerite.
Third pleonal somite ( Fig. 10 View FIG ) with moderately convex tergum and with somewhat produced posterodorsal margin. Fifth somite ( Fig. 11D View FIG ) with low, posteriorly widened plateau on dorsal surface, median part of plateau shallowly sulcate. Sixth somite ( Figs 10 View FIG ; 11D View FIG ) about 4.10 times longer than wide, 3.20-3.30 times longer than deep; dorsal surface with low, blunt submedian ridges flanking shallow median sulcus.Telson ( Fig. 11E View FIG ) shorter than sixth pleonal somite.
Eye ( Fig. 11A, B View FIG ) generally bean-shaped; cornea pigmented with light brown or gray in preservative; corneal surface distinctly faceted with moderately small lenses as in P. junceus ; maximal diameter of cornea 0.17-0.20 of carapace length; eye-stalk slightly constricted near base; papillalike projection on mesial face small. Antennular peduncle ( Fig. 11A View FIG ) falling short of midlength of antennal scale. Antennal scale ( Fig. 11A View FIG ) about 0.70 of carapace length, 3.90-4.10 times long- er than wide; lateral margin noticeably concave, distolateral tooth overreaching distal margin of lamella.
Palm of first pereopod ( Fig. 11F View FIG ) about 4.20 times longer than wide; cutting edge moderately oblique; pollex relatively small, width of palm including tip of pollex about 1.25 of width proximal to base of pollex; merus with relatively weak dorsodistal tooth. Second pereopod short, reaching or falling short of midlength of merus of first pereopod. Fourth pereopod ( Fig. 11G View FIG ) overreaching distal margin of antennal scale by half to full length of dactylus; dactylus ( Fig. 1H) not flattened with rounded dorsal surface, 0.30-0.40 of propodal length; carpus 1.0-1.12 of propodal length. Fifth pereopod ( Fig. 11I View FIG ) similar to fourth, slightly falling short of distal margin of antennal scale. Appendix masculina of male second pleopod ( Fig. 11J View FIG ) about 0.70 length of appendix interna, bearing 7 long spiniform setae.
Coloration in life
Unknown.
Size
Male CL 8.0 mm; females CL 7.6-9.7 mm.
REMARKS
The length of the rostrum shows substantial variation, although only three specimens are available for study. In the male paratype, the rostrum slightly overreaches the corneas, whereas it far exceeds them in the female paratype.
This new species is distinctive in having a number of unique characters within the species group, including the elongate, conical rostrum, the tiny, appressed lateral teeth on the rostrum, the presence of a distinct, broad plateau on the tergum of the fifth pleonal somite, the distinct submedian ridges on the sixth pleonal somite, the short, subconical dactyli of the fourth and fifth pereopods being less than half length of the propodi, and the carpi of those pereopods being subequal or longer than the propodi. The well-developed distolateral tooth of the antennal scale, which distinctly overreaches the distal lamella, distinguished Parapontophilus cornutus from most other species of the group except for P. cyrton n. sp.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.