Botryllophilus norvegicus Schellenberg 1921

• Main Authors: Kim, Il-Hoi, Boxshall, Geoff A.
• Format: Text
• Language: unknown
• Published: Zenodo 2021
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Maxillopoda; Cyclopoida; Ascidicolidae; Botryllophilus; Botryllophilus norvegicus; Arctic; Canada; Pacific; Seta; Herdman; North Atlantic; Copepods
• Online Access: https://dx.doi.org/10.5281/zenodo.4822463; https://zenodo.org/record/4822463

Botryllophilus norvegicus Schellenberg, 1921 (Figs. 39-41) Material examined. 1 ♀ (MNHN-IU-2014-17369, dissected and figured) in mçlycarpa pẚgmentata (Herdman, 1906) (MNHN-IT-2008-6635 = MNHN S1 / POL.B/405); Boiboiwaga Island, Papua New Guinea, OCDN 5782 - T (10°12.26’S, 150°44.75’E), depth 20 m, CRRF coll., 27 May 2008; 1 ♀ (MNHN-IU-2018-1961) in mçlycarpa sp., Mediterranean coast of Israel; 1 ♀ (MNHN-IU-2018-1962) in aendrçdça sp., Grand Rivière, Atlantic coast of Canada. Supplementary description based on female from Papua New Guinea . Body (Fig. 39A) T-shaped in lateral view, 4.05 mm long in dissected specimen. Broader anterior part of body unsegmented, extremely swollen posterodorsally. Narrower posterior part of body (Fig. 39B) consisting of genital and 4 abdominal somites; genital somite 464×709 μm, with broad tubercle in middle of dorsal surface; genital apertures positioned dorsally. Four abdominal somites gradually narrowing posteriorly. Caudal ramus (Fig. 39C) 267×127 μm, armed with 4 straight, blunt claws and 2 small setae; claws unequal in length, longest claw 152 μm, and second longest claw 70 μm long. Rostrum absent. Antennule (Fig. 39D) 4-segmented with indistinct articulation between last 2 segments; armature formula 12, 3, 4, and 8; 7 setae on first segment very large, exceeding length of antennule. Antenna consisting of coxa, basis, and 1-segmented endopod; endopod armed with 5 rod-shaped spines on right antenna, but with 5 slender setae on left antenna (Fig. 39E) (2 on inner margin and 3 on distal margin). Labrum (Fig. 39F) with broad posteromedial lobe and 4 patches of minute spinules along medial surface. Mandible with broadened coxal gnathobase (Fig. 39G) bearing bifurcate distal tooth and 5 small, blunt denticles on medial margin; palp (Fig. 39H) armed with 8 setae arranged as 3, 1, and 4. Maxillule (Fig. 39I) with precoxal arthrite bearing 7 setae including 1 minute seta; palp with 2 setae on medial margin and 3 setae on outer margin of basis region, 1 seta on epipodite; endopod fused with basis, armed with 3 setae on distal margin. Maxilla (Fig. 40A) obscurely segmented, with 11 setae (including 4 small and naked). Maxilliped (Fig. 40B) robust, 4-segmented; syncoxa as long as wide, with protruded outer margin, 2 minute setae on proximal inner margin, and patch of minute spinules at subdistal inner margin; basis with 2 minute inner distal setae; first endopodal segment shorter than wide, unarmed; second endopodal segment with 1 minute seta near middle; terminal claw small, about half as long as second endopodal segment. Legs 1-4 (Figs. 40-G, 41 A-C) with 1-segmented exopods and 2-segmented endopods; coxa lacking inner seta; basis with small outer seta. Exopod of right leg 1 (Fig. 40C) with 1 inner subdistal seta, in addition to 6 spines. First endopodal segment of right and left leg 1 bearing setulose tubercle on anteromedial surface. Numbers of spines (Roman numerals) and setae (Arabic numerals) on rami of legs 1-4 as follows: Leg 5 (Fig. 40H) elongate, gradually narrowing distally, with dorsolaterally curved distal part and blunt tip: armed with 4 setae; largest subdistal seta as long as proximal width of leg, other 3 setae minute. Leg 6 represented by 2 small spinules and 1 spiniform process on genital operculum. Male. Unknown. Remarks. Bçtryllçphẚlus nçrvegẚcus is known to be widely distributed in the North Atlantic and Arctic Oceans (Dudley & Illg, 1991). In the present study its known distribution is extended to include the Mediterranean Sea and the tropical West Pacific. Ooishi (1996) redescribed this species based on a single female collected in Scotland and mentioned that this species is distinguishable from other “ type A” species of the genus primarily by the humpshaped body and the presence of 5 spines on the antenna. Additional remarkable diagnostic features of this species are as follows: the caudal rami bear straight, rod-shaped claws, leg 5 is curved dorsolaterally, and the antennule bears extremely large setae on the first segment. It is noticeable that B . nçrvegẚcus displays variation in the setation pattern of the antenna and of the exopods of right leg 1 and right leg 4, as follows: (1) the right antenna is always armed with 5 spines, but left antenna may be armed with 5 spines as in Ooishi’s (1996) specimen and our specimen from the Atlantic coast of Canada, or may be armed with 5 setae as in 2 specimens each collected in Papua New Guinea and off the Mediterranean coast of Israel; (2) the exopod of the right leg 4 may be armed with 6 spines as in Ooishi’s specimen and our specimen from the Atlantic coast of Canada, or it may be armed with 7 spines as in our specimens from Papua New Guinea and off the Mediterranean coast of Israel; and (3) the exopod of right leg 1 may be armed with 6 spines plus 1 seta, as in Ooishi’s specimen and all of our specimens, but Dudley & Illg (1991) figured the exopod as bearing 7 spines (Dudley & Illg, 1991: Fig. 27). The material available for study was limited so the exact nature of this variation cannot yet be determined. : Published as part of Kim, Il-Hoi & Boxshall, Geoff A., 2021, Copepods (Cyclopoida) associated with ascidian hosts: Ascidicolidae, Buproridae, Botryllophilidae, and Enteropsidae, with descriptions of 84 new species, pp. 1-286 in Zootaxa 1 on pages 68-71, DOI: 10.11646/zootaxa.4978.1.1, http://zenodo.org/record/4820443 : {"references": ["Ooishi, S. (1996) Two ascidicolid copepods, Bctryllcph \u1e9alus macrcpus Canu and B. ncrveg \u1e9acus Schellenberg, from British waters. gcurnal cf Crustacean B \u1e9aclcgy, 16, 169 - 191. https: // doi. org / 10.2307 / 1548939"]}