Bathycopea parallela Birstein, 1963

Shimomura, Michitaka, 2008, Bathycopea (Isopoda: Sphaeromatidea: Ancinidae) from Japan, with descriptions of two new species and redescription of B. parallela Birstein, Zootaxa 1678, pp. 25-49 : 41-48

publication ID	https://doi.org/ 10.5281/zenodo.180342
DOI	https://doi.org/10.5281/zenodo.6236168
persistent identifier	https://treatment.plazi.org/id/E74BC475-A746-EE78-FF67-BDFAFAE48540
treatment provided by	Plazi
scientific name	Bathycopea parallela Birstein, 1963
status

Treatment

Bathycopea parallela Birstein, 1963 View in CoL

Figs 15–20 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 View FIGURE 19 View FIGURE 20

Bathycopea parallela Birstein, 1963: 134 View in CoL –137, figs 66–67, plate III2; Kussakin, 1979: 372 –374, figs 232–233.

Material examined. Male, 14.2 mm ( KMNH IvR 700,261), dissected and mounted on glass slides, RV Hakuho-maru, St. XR-2-1, off Kushiro, Hokkaido, 42º27.52’N, 144º15.47’E- 42º26.85’N, 144º12.98’E, 974– 965 m, mud, 3 m ORE beam trawl, 15 September, 2001, collected by Dr. S. Ohta and MS; male, 13.8 mm ( KMNH IvR 700, 267), dissected and mounted on glass slides, male, 14.6 mm ( KMNH IvR 700, 264), dissected and mounted on aluminum holders for a SEM observation, 7 males, 15.6 mm ( KMNH IvR 700,262), 15.6 mm (CBM-ZC 9398), 15.5 mm ( KMNH IvR 700,263), 15.0 mm (CBM-ZC 9399), 14.5 mm ( KMNH IvR 700,265), 14.1 mm ( KMNH IvR 700,266), 13.2 mm ( KMNH IvR 700,268), whole specimens in glass bottle, 8 ovigerous females, 12.3 mm ( KMNH IvR 700,269), 12.2 mm ( KMNH IvR 700,270), 12.2 mm (CBM-ZC 9400), 12.1 mm (CBM-ZC 9401), 11.8 mm ( KMNH IvR 700,271), 11.7 mm ( KMNH IvR 700,272), 10.9 mm ( KMNH IvR 700,273), 10.6 mm ( KMNH IvR 700,274), whole specimens in glass bottle, 7 non-ovig. females, 12.2 mm ( KMNH IvR 700,275), 12.0 mm ( KMNH IvR 700,276, 700,277), 11.3 mm ( KMNH IvR 700,278), 11.2 mm ( KMNH IvR 700279), 11.1 mm ( KMNH IvR 700,280), 10.9 mm ( KMNH IvR 700,281), whole specimens in glass bottle, RV Tansei-maru, St. KM-7, off Otsuchi, Iwate Prefecture, 39º24.39’N, 142º51.55’E, 1650–1687 m, 3 m ORE beam trawl, 8 July, 1996, collected by Mr. E. Tsuchida; male, 14.1 mm (CBM-ZC 9402), non-ovig. female, 11.7 mm (CBM-ZC 9403), whole specimens in glass bottle, TV Shinyo-maru, St. 21, Sagami-nada Sea, 34º56.46’N, 139º33.12’E- 34º53.88’N, 139º34.56’E, 1039– 1300 m, dredge, 24 October, 1996, collected by Dr. T. Komai.

Diagnosis. Body dorsally granular. Pereonites 1–7 subequal in width, each with low dorsal keel having flat apex. Pereonite 2 without anterior-lateral projections. Pleonite 1 laterally broadened; slightly arched dorsally. Pleotelson gradually decreasing in width posteriorly, without dorsal carina. Eye lobes well-developed, without ommatidia. Pereopod 1: distal corner of carpus without projection. Epistome anteriorly moderately blunt, with rounded apex, slightly surpassing frontal margin of antennule peduncular article 1; margins straight. Uropod broad, about 4.6 times as long as width, apically bifid, without large serrations on lateral margin. Pereopod 2 in male: merus and carpus as long as ischium; propodus about twice as long as carpus, slightly curved inward, projected proximally, with many robust sensory setae ventral-proximally and few simple setae and simple scales; dactylus about 1.3 times as long as propodus, curved inward, with few short simple setae apically.

Description of the reference male. Body ( Fig. 16 View FIGURE 16 A, B) about 1.7 times as long as maximum width. Head ( Fig. 16 View FIGURE 16 A) fused with pereonite 1. Pleon ( Fig. 16 View FIGURE 16 A, B) slightly narrower than pereonite 7. Pleotelson ( Fig. 16 View FIGURE 16 A) about 1.9 times as broad as long, apically rounded; dorsum moderately arched, flattened marginally. Uropodal sympod with many fine setae marginally; endopod ( Fig. 16 View FIGURE 16 A) marginally crenulated, with many short setae laterally and medially.

Antennule ( Fig. 16 View FIGURE 16 A, D): peduncle with many granules dorsally; article 1 with few short setae dorsally and many setae on margin; article 2 half as long as article 1, with many setae marginally; article 3 longest, with many setae marginally. Flagellum consisting of 13 articles: articles minute, each with few simple setae.

Antenna ( Fig. 16 View FIGURE 16 C, E): peduncle with many granules dorsally; article 1 shortest, unarmed; article 2 widest, slightly convex posterior-medially, and with some setae marginally; article 3 longest, with many setae laterally and medially; article 4 as long as article 2, with many setae laterally and medially. Flagellum consisting of 8 articles: article 1 longer than peduncular article 4, with many granules, and with many setae laterally and medially; articles 2 to 8 minute, each with few long setae and many short setae.

Left mandible ( Fig. 16 View FIGURE 16 F): article 1 of palp robust, with distal seta and many simple scales; article 2 longest, about 1.3 times as long as article 1, with 15 pectinate setae, many simple scales and few setulated scales; article 3 slender, about half as long as article 2, with 3 pectinate setae and some simple short setae. Incisor slender, with 3 teeth, and with long spine medially. Right mandible ( Fig. 16 View FIGURE 16 G): article 1 of palp with some setulated scales marginally and many simple scales dorsally, and with simple seta distally; article 2 with 14 pectinate setae, and few setulated and many simple scales; article 3 with 3 pectinate setae and some simple short setae.

Maxillule ( Fig. 16 View FIGURE 16 H) with inner lobe bearing 1 apical long and many lateral fine setae; outer lobe with 6 apical robust setae and many setulated scales and few simple scales.

Maxilla ( Fig. 16 View FIGURE 16 I) with inner lobe bearing 3 apical robust setae and many setulated scales laterally; medial lobe with 9 apical pectinate setae; outer lobe with 7 apical robust setae.

Maxilliped ( Fig. 17 View FIGURE 17 B): article 1 with short ventral seta ventrally; article 2 trapezoidal, about 3.8 times as long as article 1, with 5 pectinate setae distal-medially and few short simple setae ventrally; article 3 shorter than article 2, with 5 pectinate setae distal-medially and few short simple setae ventrally; article 4 narrow, as long as article 3, with 5 pectinate setae distal-medially; article 5 minute, with 6 apical pectinate setae; endite trapezoidal, bearing many fine setae marginally and some trifid setae ventrally, and with many setulated and simple scales ventrally, and coupling hook medially.

Pereopod 1 ( Fig. 16 View FIGURE 16 J): basis robust, without conspicuous setae; ischium about 4/7 as long as basis, unarmed; merus trapezoidal, about half as long as ischium, unarmed; carpus as long as merus, distally with few short setae, without distal projection; propodus with row of triangulate fringes on palm, with many simple scales medially and few simple setae distally; dactylus stylet-like, shorter than propodus, reaching to carpus, without setae.

Pereopod 2 ( Fig. 16 View FIGURE 16 K): basis with some fine setae dorsally; ischium half longer than basis, with few setae ventrally; merus trapezoidal, as long as ischium, with many simple setae ventrally; carpus shorter than merus, projected medially, with many simple setae medially and few short setae laterally; propodus robust, extended proximally, slightly curved inward, with 14 robust sensory setae ventral-proximally and few simple setae and simple scales; dactylus slender, longer than propodus, curved inward, with 4 short simple setae apically.

Pereopod 4 ( Fig. 17 View FIGURE 17 A): basis with few short setae; ischium about 0.4 times as long as basis, with few short setae ventrally; merus as long as ischium, with 3 long setae and many fine setae ventrally and 2 short setae distal-dorsally; carpus longer than merus, 7 long setae and many fine setae ventrally and few setae dorsally; propodus longer than carpus, with 7 long and many fine setae ventrally, and with 7 long and 5 short setae dorsally; dactylus narrowest article, with many fine setae dorsally and short seta and unguis distally

Pleopod 1 ( Fig. 17 View FIGURE 17 C) with many simple scales ventrally: peduncle about 2.5 times as broad as long, with 6 coupling hooks distal-medially and many fine setae laterally and medially; endopod about 2.4 times as long as peduncle, longer than broad, bearing many long plumose and fine simple setae; exopod narrower than endopod, as long as endopod, with many long plumose and many fine setae marginally and few simple short setae ventrally.

Pleopod 2 ( Fig. 17 View FIGURE 17 D) with many simple scales ventrally: peduncle about 2.3 times as broad as long, with 5 coupling hooks distal-medially and many fine setae marginally; endopod broad, triangulate, about 1.8 times as long as broad, 2.6 times as long as peduncle, bearing many long plumose and fine simple setae; appendix masculina as long as endopod; exopod ovate, about 0.9 times as long and about 0.6 times as wide as endopod, with many long plumose and many fine setae marginally.

Pleopod 3 ( Fig. 17 View FIGURE 17 E) with some simple and setulated scales ventrally: peduncle longer than those of pleopods 1 and 2, about 1.7 times as broad as long, with 5 coupling hooks distal-medially and many fine short setae marginally; endopod broad, subtriangulate, about 1.8 times as long as peduncle, longer than broad, bearing 13 plumose setae apically; exopod with articulated, bearing 15 plumose setae apically.

Pleopod 4 ( Fig. 17 View FIGURE 17 F): endopod slightly longer than exopod, with simple seta apically and few fine setae subdistally; exopod about 1.8 times as long as broad, bearing moderately long simple seta laterally and many fine short setae laterally.

Pleopod 5 ( Fig. 17 View FIGURE 17 G): endopod about 2.1 times as long as broad, with notch proximal-medially and many fine short setae distally; exopod slightly longer than endopod, with 6 scale patches medially, some moderately long setae and many fine short setae laterally.

Additional notes on paratype. One male was observed with SEM ( Figs. 18–20 View FIGURE 18 View FIGURE 19 View FIGURE 20 ).

Body ( Fig. 18 View FIGURE 18 A–D) covered with many granules and short setae on dorsum. Eye lobe ( Fig. 18 View FIGURE 18 A) granular dorsally, without ommatidia. Marginal setae on uropods ( Fig. 18 View FIGURE 18 E) biarticulate. Antennule peduncular ( Fig. 18 View FIGURE 18 F) with several granules. Incisors of mandibles ( Fig. 19 View FIGURE 19 A) with few scales having row of short setae. Mandibular palp ( Fig. 19 View FIGURE 19 B): articles 1 and 2 with many scales; article 3 distally truncate, without scales. Maxilliped palp ( Fig. 19 View FIGURE 19 C) covered with many scales bearing long setae. Pereopod 1 ( Figs. 19 View FIGURE 19 D, E): propodus with row of acute setae on palm; dactylus without unguis; scales of propodus with many setae agglutinated on basis. Pereopod 2 ( Fig. 19 View FIGURE 19 F): setae on basis filoplume-like, arising from deep pit. Distal sensory setae on carpus of pereopod 4 ( Fig. 20 View FIGURE 20 A) feather-like, with acute teeth bilaterally. Long sensory setae on distal-ventral margin of carpus of pereopod 4 ( Fig. 20 View FIGURE 20 B) apically bifid, setulated on frontal margin. Scales on exopod of pleopod 1 ( Fig. 20 View FIGURE 20 C) simple, rudimentary. Seta on exopod of pleopod 1 ( Fig. 20 View FIGURE 20 D) apically penicillate, arising from cuticularized sheath. Scales on second article of pleopod 1 ( Fig. 20 View FIGURE 20 E) straight, rudimentary, with row of many simple setae. Scales on scale patch of exopod of pleopod 5 ( Fig. 20 View FIGURE 20 F) well-developed, with row of many teeth.

Colour. Colour in life ( Fig. 15 View FIGURE 15 ) bright pinkish orange; eye lobes having bright pink distinct part.

Remarks. More than forty years after Birstein described Bathycopea parallela based on single female specimen collected by the Russian research vessel Vityaz from the Pacific coast of northern Honshu, Japan, I collected many specimens of the species in and around the type locality. Characters from which the present specimens were identified with B. parallela were as follows: body flat, with parallel lateral margins; pereonites each with low dorsal keel having flat apex; posterior end of pleotelson perfectly spherical, all of which were originally listed as the diagnostic characters of the species, with illustrations ( Birstein 1963).