Campylaspis brevirostris Akiyama, 2014

Akiyama, Tadashi, 2025, On some species of the genera Campylaspenis and Campylaspis (Crustacea, Cumacea, Nannastacidae) from the Sea of Japan (Northwest Pacific), with description of a new species of Campylaspenis, Zootaxa 5665 (4), pp. 543-562 : 558-559

Campylaspis brevirostris Akiyama, 2014

( Fig. 10 )

Campylaspis brevirostris Akiyama, 2014: 161–167 , figs. 1–3.

Diagnosis. Females; carapace antero-posteriorly compressed, each side with 3 weak oblique ridges; broad transverse ridge running on frontal lobe; upturned pseudorostrum very short, 0.034 –0.039 times carapace length; eye lobe semicircular. Maxilliped 3 basis inner distal corner projected; merus, carpus and dactylus serrate on inner margin. Pereopod 1 basis inner distal corner projected. Uropod peduncle 1.50–1.63 pleonite 6, 1.9–2.1 times endopod; exopod longer than endopod. Male. Pereonite 5 with genital pores on ventral surface. Maxilliped 3 propodus with finger-like process. Uropod peduncle 2.3 times pleonite 6 and 1.9 times endopod.

Material examined. 1 adult male, 3.3 mm ( NSMT Cr-32970), off Esashi , northern coast of Hokkaido, the Sea of Japan, 41°47.46΄N, 139°34.49΄E–41° 48.96΄N, 139° 34.88΄E, 563–605 m, (KT-11-9, St. E 3), 29 May 2011 .

Other material. 1 preparatory female, 2juveniles, 3 manca, Toyama Bay, 37°28.45΄N, 137°28.15΄E–37°29.18΄N, 137°28.86 ΄, 160–173 m, 31 May 2011 (KT-11-9, St. T1 ); 3 ovigerous females, 7 preparatory females, 2 subadult males, 11 juveniles, 4 manca, Toyama Bay, 37°29.18΄N, 137°33.25΄E–37°29.35΄N, 137°31.96΄E, 383–460 m, 31 May, 2011 (KT-11-9, St. T3 ); 4 ovigerous females, 3 preparatory females, 2 subadult males, 6 juveniles, 1 manca, Toyama Bay, 37°19.80 N, 137°33.38΄E–37°20.02΄N, 137°34.20΄E, 561–583 m, 1 June, 2011 (KT-11-9, St. T4 ); 9 ovigerous females, 2 preparatory females, 1 subadult male, 8 juveniles, Toyama Bay, 37°18.45΄N, 137°31.77΄E– 37°18.66΄N, 137°32.85΄E, 794–808 m, 1 June, 2011 (KT-11-9, St. T5 ); 1 subadult male, 3 juveniles, 1 manca, north of Noto Peninsula, 37°57.06΄N, 136°56.60΄E–37°57.04΄N, 136°58.23΄E, 201–203 m, 1 June, 2011 (KT-11-9, St. N 2); 5 ovigerous females, 1 preparatory female, 4 juveniles, north of Noto Peninsula, 38°03.25΄N, 136°53.39΄E– 38°03.82΄N, 136°55.13΄E, 402–411 m, 1 June, 2011 (KT-11-9, St. N 3); 1 preparatory female, 2 subadult males, 6 juveniles, 1 manca, north of Noto Peninsula , 38°08.04΄N, 136°49.64΄E–38°09.00΄N, 136°51.20΄E, 603–622 m, 1 June, 2011 (KT-11-9, St. N 4) .

Remarks. An additional adult male specimen found in the present study agrees well with a male specimen in the original description ( Akiyama, 2014). A noteworthy character is a pair of large genital pores on the ventral surface of pereonite 5 (arrowhead in Fig. 10A ), also found in C. crispa .

Campylaspis brevirostris closely resembles C. bacescui from the southern coast of Argentine, Falkland Isles, Straight of Magellan, 82–361 m, western Atlantic, but is distinguished by (1) lower margin of carapace serrated in both sexes (anterior half of lower margin serrated in female, not serrated in male of C. bacescui ), (2) carapace of adult male is not dorso-ventrally compressed, but is spherical (dorso-ventrally compressed in C. bacescui ), (3) propodus of maxilliped 3 with finger-like process in adult male (without finger-like process in C. bacescui ).

Distribution. Japanese coast of the Sea of Japan, 160–808 m

Figures

FIGURE 10. Campylaspis brevirostris Akiyama, 2014, adult male. A, pereonite 5 with pereopod 5, view from below; B, maxilliped 3; C, propodus and dactylus of maxilliped 3.