Botryllophilus guadeloupensis, Kim & Boxshall, 2021

Kim, Il-Hoi & Boxshall, Geoff A., 2021, Copepods (Cyclopoida) associated with ascidian hosts: Ascidicolidae, Buproridae, Botryllophilidae, and Enteropsidae, with descriptions of 84 new species, Zootaxa 1, pp. 1-286 : 64-67

Botryllophilus guadeloupensis sp. nov.

( Figs. 36-38 )

Type material. Holotype ♀ (MNHN-IU-2018-1959), 2 ♀♀ paratypes (intact, MNHN-IU-2018-1960), and 2 ♀♀ paratypes (dissected, MNHN-IU-2014-17368) from ieptçclẚnẚdes latus Monniot F., 1983; Guadeloupe Stn 83-13, SE of Îlet Fajou, near Passe à Colas, depth 5-20 m, Monniot coll., 29 March 1983.

Etymology. The name of the new species is taken from its type locality, Guadeloupe.

Description of female. Body ( Fig. 36A ) small, rather stout, nearly symmetrical; body length 797 μm in largest specimen (dissected), 718 μm in smallest specimen. Broader anterior part of body occupying about 65% of body length, consisting of cephalosome and first to fifth pedigerous somites: first to fourth pedigerous somites each with weakly developed dorsal tergite. Narrower posterior part ( Fig. 36B ) consisting of genital somite and 7 abdominal annulations (8-annulate abdomen observed in 1 of 5 specimens). Genital somite much wider than long (68×159 μm); genital apertures positioned dorsally. Abdomen gradually narrowing distally: first to sixth abdominal annula- tions short, 128 μm long in total. Last annulation (anal somite) ( Fig. 36C ) wider than long (68×82 μm), ornamented with 2 horizontal rows of minute spinules on proximal part of ventral surface. Caudal ramus ( Fig. 36D ) slightly longer than wide (36×30 μm), armed with 4 claws and 2 setae; outermost claw bluntly tipped and weakly sclerotized.

Rostrum as simple frontal lobe on cephalosome. Antennule short, 4-segmented; armature formula 10, 4, 2, and 11+aesthetasc; terminal segment subdivided by incomplete posterior suture line into proximal region bearing 4 setae and distal region bearing 7 setae plus 1 aesthetasc. Right antenna ( Fig. 36F ) 3-segmented, consisting of coxa, basis, and 1-segmented endopod; endopod about 4 times longer than wide (64×16 μm), armed with 8 elements consisting of 2 proximal setae plus 1 distal spine on inner margin and 5 unequal setae on distal margin, innermost seta on distal margin minute, setule-like. Left antenna differing from right antenna in having 2 longer outer setae on distal margin of endopodal segment.

Labrum weak, easily destroyed. Mandible ( Fig. 36G ) bearing 3 teeth on coxal gnathobase; palp as usual for genus, bearing 9 setae arranged as 3, 2, 2, and 2. Maxillule ( Fig. 36H ) with 5 distinct setae and 1 minute seta on arthrite of precoxa; coxobasis with 2 setae (both with swollen base) on medial margin, 3 setae on outer margin, 1 naked seta at outer proximal corner, and 1 tapering process in outer distal region; endopod distinctly defined from basis and armed with 3 setae. Maxilla ( Fig. 36I ) indistinctly 2-segmented, with 10 setae. Maxilliped ( Fig. 37A ) 4-segmented; syncoxa unarmed and unornamented; basis with 2 small, equal setae and 1 row of minute spinules subdistally; first endopodal segment short and unarmed; second endopodal segment about 1.8 times longer than wide, bearing small seta distally on inner margin; terminal claw as long as second endopodal segment, bearing 2 tooth-like processes, 1 proximally and 1 subdistally on inner margin.

Legs 1-4 ( Figs. 37 B-E, 38A-D) biramous, asymmetrical. In left leg 4 ( Fig. 38D ) protopod divided into coxa and basis, but in other legs coxa and basis fused to form unsegmented protopod bearing 1 seta on outer margin and row of spinules at inner distal corner. Exopods 1-segmented in right and left legs 1 and 2, but 2-segmented in endopods and in both rami of legs 3 and 4. Numbers of spines (Roman numerals) and setae (Arabic numerals) on right and left legs 1-4 as follows:

Leg 5 ( Fig. 38E ) large, extending beyond posterior margin of genital somite, about 2.4 times longer than wide (160×67 μm), evenly tapering, armed with 4 setae. Leg 6 represented by 2 small spinules and 1 spinule-like process on genital operculum.

Male. Unknown.

Remarks. In B. guadelçupensẚs sp. nov. the exopods of right legs 1-4 are armed with 6 spines whereas the exopods of left legs 1-4 are armed with 5 setae. This characteristic leg setation is unique within Bçtryllçphẚlus and typifies the new species. The 3-segmented condition of the antenna (with a 1-segmented endopod) is also a significant feature of B. guadelçupensẚs sp. nov., because it is shared only with B. nçrvegẚcus (see Ooishi, 1996) and B. lçngẚpes sp. nov., although the latter two species are not similar to B. guadelçupensẚs sp. nov. in female body form, or in the setation patterns of the antenna and swimming legs.

Figures

FIG. 36. Bçtryllçphẚlus guadelçupensẚs sp. nov., female. A, habitus, right; B, posterior part of body, dorsal; C, posterior part of abdomen, ventral; D, caudal ramus; E, antennule; F, antenna; G, mandible; H, maxillule; I, maxilla. Scale bars: A, 0.1 mm; B, C, 0.05 mm; D-I, 0.02 mm.

FIG. 37. Bçtryllçphẚlus guadelçupensẚs sp. nov., female.A, maxilliped; B, right leg 1; C, left leg 1; D, right leg 2; E, left leg 2. Scale bars: 0.02 mm.

FIG. 38. Bçtryllçphẚlus guadelçupensẚs sp. nov., female. A, right leg 3; B, left leg 3; C, right leg 4; D, left leg 4; E, leg 5. Scale bars: A-D, 0.02 mm; E, 0.05 mm.