Campylaspis crispa Lomakina, 1955

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 : 553-558

Campylaspis crispa Lomakina, 1955

( Figs. 7–9 )

Campylaspis crispa Lomakina, 1955: 132–133 , figs. 32, 33.

Campylaspis sp. 1 Akiyama, 2014: 167–168.

Diagnosis. Females: Carapace with three distinct oblique ridges on each side, connected on dorsal surface; short vertical ridge connecting 1st and 2nd oblique ridges; 1st oblique ridge branch and re-unite on dorsal surface, making encircled region; pseudorostrum 0.08–0.14 times carapace length, not upturned; eye lobe semicircular; frontal lobe with no transverse ridge. Pereopod 1 inner distal corner projected. Uropod peduncle 1.8–2.1 times pleonite 6, 2.4–3.0 times exopod and 2.1–2.7 times endopod. Males. Genital pore present under ventral surface of pereonite 5; uropod peduncle 2.4–3.0 times pleonite 6, 2.6–2.7 times exopod and 2.0–2.2 times endopod; exopod 0.8 times endopod.

Material examined. 17 females, 4 males, 9 juveniles (includind dissected 3 ovigerous females, 3.8–4.3 mm, 2 preparatory females, 3.9, 4.1 mm, 3 adult males, 4.7–5.2 mm) ( NSMT Cr-32969), off Esashi , 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 ; 14 females, 4 males, 10 juveniles ( NSMT Cr-22790), off Esashi , Hokkaido, the Sea of Japan, 41°50.26΄N, 139°34.03΄E– 41°48.70΄N, 139° 34.18΄ E, 388–538 m (KT-11-9, St. E 2), 29 May 2011 ; 53 females, 6 adult and 16 subadult males, 11 juveniles ( NSMT Cr-22789), Musashi Bank , 44°40.48΄N, 140°02.38΄E–44°39.53΄N, 140°002.83΄E, 198–206 m (KT-11-9, St. M 2), 28 May 2011 ; 3 females, 6 juveniles, 3 manca, Toyama Bay , 37°28.77΄N, 137°29.07΄E– 37°29.53΄N, 137°28.63΄E, 207–258 m (KT-11-9, St. T2 ), 31 May 2011 ; 13 females, 7 males, 29 juveniles, 12 manca ( NSNT Cr-22791), 37°19.80΄N, 137°33.38΄E–37°20.02΄N, 137°34.20΄E, 561–583 m (KT-11-9, St. T4 ), 1 June 2011 ; 8 females, 4 males, 13 juveniles, Toyama Bay , 37°18.45΄N, 137°31.77΄E–37°18.66΄N, 137°32.85΄E, 794–808 m (KT-11-9, St. T5 ), 1 June 2011 .

Description. 5 ovigerous females, 3.6–4.3 mm ( Figs. 7 , 8 ). Carapace ( Fig. 7A, B ) 0.43–0.45 times total body length, 1.36–1.43 times width and 1.69–1.83 times depth, with sparse short setae; integument covered with scale-like sculpture ( Fig. 7C ); each side with 3 distinct oblique ridges running parallel, connected at dorsal surface, 1st oblique ridge branch and re-unite on dorsal surface, making encircled round region; 1st and 2nd oblique ridges connected by a short vertical ridge near lower margin of carapace; third oblique ridge running near posterior end of carapace; pseudorostrum 0.08–0.14 times carapace width, not upturned; width of semicircular eye lobe 0.07–0.10 times carapace width, 0.9–1.1 times eye lobe length; frontal lobe with faint or no transverse ridge; antennal notch obsolete; lower margin with minute teeth. Pereon ( Fig. 7A ) 0.30–0.50 times carapace length. Pleon ( Fig. 7A ) 0.36– 0.39 times total body length; pleonite 2–5 with weak lateral ridge on each side; pleonite 6 ( Fig. 8G ) length 0.8–0.9 times as long as wide.

Antenna 1 ( Fig. 7D ), peduncle basal article curved, 1.2–1.4 times articles 2 and 1.3–1.5 times article 3, with an simple seta on distal corner; article 2 with 1 short simple seta on distal corner; article 3 0.9–1.0 times article 2; main flagellum tri-articulate, 0.9–1.1 times peduncle article 3; basal article 1.0–1.3 times combined length of articles 2 and 3; accessory flagellum uni-articulate, 0.3 times article 1 of main flagellum. Antenna 2 ( Fig. 7E ) uni-articulate, without setae. Left and right mandibles ( Fig. 7F ) broad at base; with 3 and 4 robust setae with many minute tubercles respectively; molar process styliform, 4-dentate; lacinia mobilis 4-dentate; incisor process 6 dentate. Maxilla 1 ( Fig. 7G ) outer endite with 9 dentate or simple robust setae, lower 2 setae a little apart from the other setae; narrow endite with 5 ciliated or simple setae; palp with terminal seta. Maxilla 2 ( Fig. 7H ) narrow distally, with 3 terminal and 1 subterminal setae. Maxilliped 1( Fig. 7I, J ) with 9 branchial lobules; merocarpus with 3–5 simple setae on distal region and 3–5 short simple setae on inner margin; dactylus minute, 0.040 – 0.056 times merocarpus length. Maxilliped 2 ( Fig. 7K ) basis 0.7–0.9 times distal articles together; ischium with plumose seta on inner distal corner; carpus with 2 tubercles and 2 simple setae on inner margin; joint between carpus and propodus strongly bend; propodus long, with 1 long terminal spine; dactylus with 3 long terminal spines; coxa with 7–8 setae. Maxilliped 3 ( Fig. 8A ) basis 0.7–0.8 times distal articles together; inner distal corner projected, with 2 plumose setae and 2–5 spines; outer distal corner with 1–2 plumose setae; ischium short; merus 1.1–1.2 times combined length of carpus and propodus, with 8–10 teeth and 6–7 short simple setae on inner margin and 4–10 teeth and 1 plumose seta on outer margin; carpus with 2–4 teeth and 3 plumose and 0–1 simple setae on inner margin and 3 teeth and plumose seta on outer margin; propodus 1.7–2.1 times dactylus, with 5 teeth and 2 plumose setae on inner margin and 1 plumose seta on outer distal corner; dactylus with 3 terminal setae; exopod flagellum of 3 articles.

Pereopod 1 ( Fig. 8B ) basis 0.8–0.9 times distal articles together; inner distal corner projected, with 2 plumose setae; outer distal corner with 0–1 simple seta; ischium with plumose seta and 0–1 short simple seta on inner margin; merus 0.7–0.8 times combined length of carpus and propodus, with 0–1 tooth, 2 plumose and 3 simple setae on inner margin, 3–6 teeth and 2 plumose setae on outer margin; carpus with 3–5 teeth and 2–3 simple setae on inner margin, 2 plumose setae on outer margin; propodus with 2–3 teeth and 3 simple seta on inner margin, 2–3 plumose and 0–1 simple setae on outer margin; dactylus with 1–2 terminal setae; exopod flagellum of 4 articles. Pereopod 2 ( Fig. 8C ) basis 0.5–0.6 times distal articles together, with plumose seta on distal corner; dactylus 1.3–1.6 times carpus, with 8–11 simple setae; exopod flagellum of 4 articles. Pereopod 3 ( Fig. 8D ) basis 1.3–1.5 times distal articles together, with 3 plumose and 2 simple setae on lateral margin. Pereopod 4 ( Fig. 8E ) basis 0.8–1.0 times distal articles together, with 1–2 plumose and 1 simple setae on lateral margin. Pereopod 5 ( Fig. 8F ) basis 0.5 times distal articles together.

Uropod ( Fig. 8G ) peduncle 1.8–2.1 times pleonite 6 length, 2.4–3.0 times exopod, 2.1–2.7 times endopod, inner and outer margin serrated; exopod 0.9 times endopod, with long and short simple terminal seta; endopod uni-articulate, with 4 spiniform setae on inner margin and terminal seta.

3 adult males, 4.7–5.2 mm ( Fig. 9 ). Carapace ( Fig. 9A, B ) 0.37–0.40 times total body length, 1.41–1.47 times width, 2.01–2.14 times depth, with few short setae; each side with distinct 3 oblique ridges connected at dorsal surface; 1 short vertical ridge connects 1st and 2nd oblique ridges; pseudorostrum ( Fig. 9A–C ) 0.076 –0.079 times carapace length, not upturned; width of eye lobe 0.10–0.12 times carapace width, 1.0–1.2 times eye lobe length; corneal lenses absent; frontal lobe without transverse ridge; antennal notch shallow ( Fig. 9C ); lower margin of carapace not serrated. Pereon ( Fig. 9A, B ) 0.54–0.67 times carapace length; pereonite 5 with a couple of genial pores (arrowheads) near basal region of pereopod 5 ( Fig. 9D, E ); Pleon ( Fig. 9A ) 0.38–0.39 times total body length, with lateral grooves; pleonite 6 0.8–1.0 times as long as wide.

Antenna 1 ( Fig. 9F ), peduncle basal article curved, 1.4–1.6 times article 2 and 1.4–1.6 times article 3; article 3 0.9–1.0 times article 2; Main flagellum tri-articulate, 1.2 times peduncle article 3; articles 2 and 3 with 1 aesthetasc, respectively; accessory flagellum uni-articulate, 0.3–0.4 times main flagellum article 1. Antenna 2 ( Fig. 9G ) peduncle articles 4 and 5 with numerous setae; peduncle article 5 2.0–2.2 times article 4; flagellum of 20 articles, exceeding posterior end of pleon. Maxilliped 3 ( Fig. 9H ) basis 1.0 times distal articles together, with 0–1 plumose setae on inner margin, 2 plumose setae on outer distal corner; merus 1.0–1.1 times combined length of carpus and propodus, with 7–10 teeth and 6–7 simple setae on inner margin, 7–8 teeth and plumose seta on outer margin; carpus with 3–4 teeth and 3 simple setae on inner margin, 2–3 teeth and plumose seta on outer margin; propodus with 4–5 teeth and 3 plumose setae on inner margin, plumose seta on outer distal corner; dactylus with 3–4 terminal setae; exopod flagellum 6-articulate.

Pereopod 1 ( Fig. 9I ), basis 0.9–1.0 times distal articles together; inner distal corner of basis projected, with 2 plumose setae; merus 0.7 times combined length of carpus and propodus, with 2–3 plumose and 3 simple setae on inner margin, 7–8 teeth and 2 pluumose setae on outer margin; carpus with 4 teeth and 2–3 simple setae on inner margin, 3–5 teeth and 2 plumose setae on outer margin; propodus with 3 teeth on inner margin, 2 teeth and 2–3 plumose setae on outer margin; exopod flagellum 6-articulate. Pereopod 2 ( Fig. 9J ) basis 0.7 times distal articles together, with plumose seta on inner and outer distal corner, respectively; dactylus 1.2–1.4 times carpus, with 11–12 setae; exopod flagellum 7-articulate. Pereopod 3 ( Fig. 9K ) basis 1.7–2.0 times distal articles together, with 2 plumose setae on outer margin; exopod flagellum 6-articulate. Pereopod 4 ( Fig. 9L ) basis 1.1–1.2 times distal articles together, with 2 plumose setae on inner distal corner, exopod flagellum of 5 articles. Pereopod 5 ( Fig. 9M ) basis 0.6–0.7 times distal articles together, with 2–3 plumose setae on lateral margin.

Uropod ( Fig. 9N ) peduncle 2.4–3.0 times pleonite 6, 2.6–2.7 times exopod and 2.0–2.2 times endopod, with 8–9 setae on inner margin; exopod 0.8 times endopod, with ciliated seta on inner margin and 2 terminal setae; endopod uni-articulate, with 10 spiniform setae on inner margin and terminal seta.

Remarks. The original description of Campylaspis crispa was based on female specimens from Petra Verikogo, Russian coast of the Sea of Japan ( Lomakina, 1955). Akiyama (2014) did not assign Japanese specimens( Campylaspis sp. 1 ) to C. crispa , due to the different lengths of the uropod peduncle to the endopod (twice in Japanese specimens, three times in Russian specimens). However, on closer inspection, considerable variation in the ratio (2.1–2.7 to endopod) in the Japanese specimens shows that they should be identified as C. crispa .

Female specimens of Campylaspis crispa closely resemble females of Campylaspenis sigeogamoi , but are distinguished by (1) 3 oblique ridges on carapace distinct (weak in C. sigeogamoi ), (2) anterior end of scale-like sculpture on carapace not forming minute spine (forming minute spine directed outward in C. sigeogamoi ), and (3) uropod peduncle not slender (slender in C. sigeogamoi ). Comparing the specimens from the same sediment sample (KT-11-9, St. E3), the total body length of C. crispa (3.8–4.3 mm in ovigerous females, 3.9, 4.1 mm in preparatory female, 4.7–5.2 mm in adult males) was larger than C. sigeogamoi (3.0– 3.4 mm in ovigerous females, 3.8–3.9 mm in adult males).

In adult male specimens, a pair of large genital pores are present on the ventral surface of pereonite 5, as is also found in Campylaspis brevirostris .

Distribution. Russian and Japanese coast of the Sea of Japan, 10–994 m in Russia and 198–808 m in Japan.

Figures

FIGURE 7. Campylaspis crispa Lomakina, 1955 ovigerous female. A, lateral view; B, anterior portion of body, from above; C, integument of carapace; D, antenna 1; E, antenna 2; F, mandibles; G, maxilla 1; H, maxilla 2; I, J, maxilliped 1;K, maxilliped 2.

FIGURE 8. Camplaspis crispa Lomakina, 1955, ovigerous female. A, maxilliped 3; B–F, pereopods 1–5; G, uropod with pleonite 6.

FIGURE 9. Campylaspis crispa Lomakina, 1955, adult male. A, lateral view; B, anterior portion of body, from above; C, anterior portion of carapace, lateral view; D, pereonite 5 with pereopod 5, lateral view; E, pereonite 5 with pereopod 5, view from below; F, G, antenna 1 and 2; H, maxilliped 3; I–M, pereopods 1–5; N, uropod with pleonite 6.