Metacrangon holthuisi Komai 2010
Creators: name: Komai, Tomoyuki
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Crangonidae
Metacrangon
Metacrangon holthuisi

description: <i>Metacrangon holthuisi</i> Komai, 2010 (Fig. 41) <i>Metacrangon holthuisi</i> Komai, 2010: 370, figs 1, 2 [type locality: Sagami Sea, off Sunosaki, Tateyama, 1039–1300 m]; Komai 2011: 286, fig. 1C; De Grave &amp; Fransen 2011: 457 (list). <b>Material examined.</b> Holotype: male (cl 6.0 mm), RV <i>Shin’yo-maru</i>, 1996 cruise, stn 21, off Sunosaki, Tateyama, Sagami Sea, 34°56.46’N, 139°33.12’E, 1039–1300 m, 24 October 1996, dredge, CBM-ZC 5347. Non-type: RV <i>Tansei-maru</i>, KT 07-31, stn L-2’-1000, Sagami Sea, S of Jogashima, 35°02.78’N, 139°33.27’E to 35°03.04’N, 139°33.74’E, 633–716 m, 28 November 2007, beam trawl, 2 males (cl 4.0, 4.4 mm), 2 females (cl 3.7, 4.0 mm), CBM-ZC 10092. <b>Diagnosis.</b> <i>Male</i>. Rostrum narrow triangular with acute tip in dorsal view, slightly ascending (angle about 25° against horizontal plane of carapace), overreaching antennal teeth by half-length (0.3 times as long as carapace); ventral carina low. Carapace with subequal, similarly ascending middorsal teeth; anterior middorsal tooth arising at about 0.2 of carapace length; posterior tooth arising at 0.6 of carapace length; submedian teeth present; postorbital lobe slightly produced; antennal tooth ascending in similar degree of rostrum, acuminate; branchiostegal tooth strong, directed slightly laterally in dorsal view, ascending in similar degree to rostrum in lateral view. First and second abdominal somites rounded dorsally, third and fourth somites each with weakly delimited middorsal carina, fifth somite with broad, better delimited middorsal carina. First to third abdominal pleura rounded marginally. Sixth abdominal somite with distinct submedian carinae. Telson with 2 pairs of dorsolateral spines. Eye approximately as long as wide. Antennular peduncle slightly falling short of distal margin of antennal scale; first segment with short, blunt distolateral process; stylocerite reaching midlength of first segment; second segment widened distally, with prominent, blunt distolateral process. Antennal scale about 0.6 times as long as carapace, 2.9–3.0 times longer than wide; lateral margin concave; distolateral tooth distinctly overreaching lamella. Third maxilliped with ultimate segment 7.0 times longer than wide. First pereopod with palm 3.5 times longer than wide. Only young female specimens available, generally similar to male specimens except for proportionally shorter outer antennular flagellum consisting of 5 or 6 articles. <b>Description.</b> See Komai (2010). <b>Coloration.</b> Entirely brownish, darker on carapace; cornea black, reflective (Komai 2011). <b>Size</b>. Largest male cl 6.0 mm; known largest female cl 4.0 mm. <b>Distribution.</b> Known only from the Sagami Sea, central Japan (Fig. 41); 633–1300 m. <b>Remarks.</b> As discussed by Komai (2010), <i>Metacrangon holthuisi</i> is most similar to <i>M. cornuta</i> and <i>M. spinirostris</i>. The length of the rostrum is clarified to vary individually in <i>M. holthuisi</i>, and thus this character is not reliable in distinguishing <i>M. holthuisi</i> from the latter two species. Nevertheless, the subequal and similarly ascending middorsal teeth on the carapace and blunt distolateral processes on the first and second segments of the antennular peduncle immediately distinguish <i>M. holthuisi</i> from <i>M. cornuta</i> and <i>M. spinirostris</i>. In addition, the rostrum ascends less in <i>M. holthuisi</i> than in the latter two species.
description: Published as part of <i>Komai, Tomoyuki, 2012, 3468, pp. 1-77 in Zootaxa 3468</i> on page 55
description: {"references": ["De Grave, S. &amp; Fransen, C. H. J. M. (2011) Carideorum catalogus: the Recent species of the dendrobranchiate, stenopodidean, procarididean and caridean shrimps (Crustacea: Decapoda). Zoologische Mededelingen, 85, 1 - 588."]}