Botryllophilus tuberculatus Kim & Boxshall 2021, sp. nov.
Creators: name: Kim, Il-Hoi
name: Boxshall, Geoff A.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Cyclopoida
Ascidicolidae
Botryllophilus
Botryllophilus tuberculatus

description: Botryllophilus tuberculatus sp. nov.   
(Figs. 42-44)  
 Type material. Holotype ♀ (MNHN-IU-2018-1965), ♀ paratype (MNHN-IU-2018-1966), and ♀ paratype (dis- sected, MNHN-IU-2014-17371) from mseudçdẚstçma delẚcatum Monniot C., Monniot F., Griffiths & Schleyer, 2001; Sodwana Bay, South Africa, Schleyer coll., 1993.   
 Etymology. The specific name refers to the presence of a pair of posteroventral tubercles on the fifth pedigerous somite.   
 Description of female. Body (Fig. 42A, B) rather stout, slightly asymmetrical, 1.10 mm long in largest dissected specimen. Anterior part of body gradually broadening posteriorly, with distinct cephalic shield and weak lateral constrictions. Fourth and fifth pedigerous somites not defined from each other; leg 5 positioned laterally. Fifth pedigerous somite bearing paired blunt tubercles posteroventrally (indicated by arrowhead in Fig. 42 A-C) on both sides Posterior part of body consisting of genital somite and 4 abdominal somites; 110×190, 75×135, 90×125, 77×113, and 140×98 μm, respectively. Genital somite with densely sclerotized region surrounding copulatory pore on ventral surface; genital apertures positioned dorsally. Anal somite about 1.4 times longer than wide. Caudal ramus (Fig. 42D) about 1.55 times longer than wide (51×33 μm), armed with 4 claws and 2 setae; second inner claw strongly curved, not articulated from ramus; 1 outer claw bluntly tipped, gradually broadening distally, with serrate, membranous cap at tip; 2 caudal setae unequal in length.   
Rostrum absent. Antennule (Fig. 42E) short, 169 μm long, 4-segmented, but articulation between first and sec- ond segments distinct only on dorsal surface; armature formula 8, 5, 2+aesthetasc, and 11+aesthetasc; 3 larger setae on first, 2 on second, 1 on each of third and apical segments. Left antenna (Fig. 42F) 4-segmented, slender, with unarmed coxa, basis, and first endopodal segment; second endopodal segment 3.4 times longer than wide (55×16 μm), shorter than basis, armed with 7 setae (4 of them shorter and bluntly tipped); longest of distal setae 95 μm long. Second endopodal segment of right antenna (Fig. 42G) longer than that of left antenna, 64×14 μm, armed with 7 spiniform setae bearing blunt, serrate distal tips, all setae at most 50 μm long, shorter than second endopodal seg- ment.  
Labrum (Fig. 42H) with thick lateral borders and linguiform posteromedian lobe ornamented with minute setules distally. Mandible (Fig. 42I) bearing bifurcate distal tooth and 3 smaller, blunt teeth on coxal gnathobase; palp bearing blunt tubercle on medial margin and armed with 9 setae arranged as 3, 2, 2, and 2; distal of 3 proximal setae and 1 of subterminal setae naked. Maxillule (Fig. 42J) with 6 distinct setae on precoxal arthrite; coxobasis with 2 setae on medial margin and 3 setae on outer margin, plus outer distal lobe; endopod well-defined from basis, armed with 3 setae. Maxilla (Fig. 43A) indistinctly 3-segmented and armed with 2, 4, and 3 setae on first to third segments, respectively; one of 4 setae on second segment very small. Maxilliped (Fig. 43B) robust, 4-segmented; syncoxa much broader than long, with 2 minute setae on medial margin; basis with 2 minute setae; short first endopodal segment unarmed; second endopodal segment with 2 minute setae (1 subdistal and 1 distal); terminal claw obscurely articulated from second endopodal segment, bearing 2 denticles on inner margin (1 proximal and 1 subdistal).  
Legs 1-4 (Figs. 43 C-F, 44A-D) biramous, asymmetrical; coxa unarmed; basis with 1 outer seta. Exopods of legs 1-4 unsegmented. Endopod of right leg 1 segmented only on posterior surface. Endopod of left leg 1 unsegmented. Endopods 2-segmented in right and left legs 2-4. Second endopodal segment of right leg 3 with 2 spines and 3 setae (Fig. 44A). Second endopodal segment of left leg 3 with 1 spine and 4 setae. Numbers of spines (Roman numerals) and setae (Arabic numerals) on right and left legs 1-4 as follows:  
Leg 5 (Fig. 43G) small, positioned laterally on fifth pedigerous somite, strongly tapering, 113×63 μm, armed with 4 setae (1 on proximal dorsal margin and 3 distal); distal longest seta 100 μm long, slightly shorter than seg- ment. Leg 6 (Fig. 44E) represented by 1 small spine and 1 spiniform process on genital operculum; about 9 small surface tubercles present near leg 6.  
 Male. Unknown.   
 Remarks. Bçtryllçphẚlus tuberculatus sp. nov. most closely resembles B. dẚstẚnctus Ooishi, 2012 known as an associate of budẚstçma sp. in Madagascar. They have the same number of armature elements on the antenna and on legs 1-4 and have similar setation on the antennule. Distinguishing the new species from B. dẚstẚnctus is easy: B. tuberculatus sp. nov. possesses a pair of tubercles in the posteroventral region of the fifth pedigerous somite (vs. no such tubercles present in B. dẚstẚnctus), the exopod of right leg 3 is unsegmented (vs. 2-segmented in B. dẚstẚnctus), the exopod of left leg 4 is short and unsegmented (vs. elongate and 2-segmented in B. dẚstẚnctus), and the second endopodal segment of left leg 3 is armed with 1 spine plus 4 setae (vs. 5 setae only in B. dẚstẚnctus). The differences are sufficient to justify the establishment of a new species.
description: 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 72-75, DOI: 10.11646/zootaxa.4978.1.1, http://zenodo.org/record/4820443