Periboia tahitiensis Kim & Boxshall 2021, gen. et sp. nov.
Creators: name: Kim, Il-Hoi
name: Boxshall, Geoff A.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Cyclopoida
Enteropsidae
Periboia
Periboia tahitiensis

description: Periboia tahitiensis gen. et sp. nov.   
(Figs. 175, 176)  
 Type material. Holotype ♀ (MNHN-IU-2014-21580, dissected and mounted on 2 slides) from Asc ẚdẚa archaẚa Sluiter, 1890 ( MNHN-IT-2008-866 = MNHN P5 / ASC.A/166); Tahiti, N. Moorea I., W. Motu d’Irioa, Stn M 13, Monniot coll., June 1984.   
 Etymology. The type locality provides the name for the new species.   
 Description of female. Body (Fig. 175A) large, vermiform, divisible into prosome and urosome; body length 11.0 mm; maximum width 2.80 mm (across third pedigerous somite). Prosome consisting of cephalosome and first to fourth pedigerous somites, incompletely segmented, but clearly defined by deep constrictions between somites. Cephalosome small, circular, 1.14× 1.36 mm. First to fourth pedigerous somites all similar in length and lacking dorsal tergite. Urosome (Fig. 175B) 3-segmented, consisting of fifth pedigerous somite, genital double-somite, and unsegmented abdomen. Fifth pedigerous somite elongated, 1.36× 1.09 mm, bearing leg 5 posterolaterally. Genital double-somite obscurely defined from fifth pedigerous somite, wider than long, about 0.45× 1.09 mm, laterally convex; genital apertures located dorsolaterally, covered by leg 5. Abdomen 770×710 μm, lacking anal operculum or anal prominence. Caudal rami (Fig. 175B) elongate, about 3.8 times longer than wide (727×190 μm), unarmed, with parallel lateral margins, and rounded distal margin.   
Rostrum represented by short ridge between antennules (Fig. 175C). Antennule (Fig. 175D) 2-segmented; proximal segment slightly longer than wide (139×124 μm), narrowing distally, armed with 1 seta on posterior margin and 1 minute setule subdistally; distal segment about 1.7 times longer than wide (68×39 μm), unarmed. Antenna (Fig. 175E) curved, digitiform, 3-segmented, unarmed; first to third segments 89×91, 76×67, and 98×45 μm, re- spectively, narrowing from proximal to distal; anterior surface of second and third segments covered with minute spinules.  
Labrum (indicated by Lb in Fig. 175C) rudimentary, flexible, not covering any oral appendages. Mouth (indicated by arrowhead in Fig. 175C) visible just posterior to labrum. Mandible (Fig. 175F) positioned lateral to mouth, short, bearing strong claw distally, with dense sclerotized area between proximal part and claw. Maxillule (Fig. 175G, H) bilobed; larger inner lobe with 2 broad, unequal setae apically and ornamented with numerous minute spinules on distal surfaces and setae; small outer lobe digitiform, tipped with 1 spine (or spiniform seta). Maxilla (Fig. 175I) bilobate, with short proximal part; both lobes ornamented with transverse rows of minute spinules; inner lobe (endite of syncoxa) tapering, tipped with 1 broad, spinulose seta; outer lobe longer than inner, rectangular, armed with 1 small spine on outer margin and 2 triangular spines at apex. Ventral surface of cephalosome between left and right maxillae bearing broad, linguiform protuberance (arrowed in Fig. 175C). Maxilliped absent.  
Legs 1-4 all same in form and structure (Fig. 176 A-C); each leg consisting of small free exopod plus fleshy, tapering, unsegmented process formed by complete fusion of protopod and endopod. Exopods flattened, lamellate, tapering, tipped with small claw (or claw-like process). Legs 2-4 larger than leg 1.  
Leg 5 (Fig. 176D) small, lamellate, unarmed, wider than long (376×636 μm), narrowing distally, and covering only anterior part of genital double-somite. Leg 6 (Fig. 176E) probably represented by 2 small cusps on genital operculum.  
 Male. Unknown.   
 Remarks. This species, with a female body length of 11.0 mm, is the largest known member of the family Enteropsidae.   
  Genus Enteropsis C.W.S. Aurivillius, 1885    
 Diagnosis. Female: Body eruciform or vermiform, unsegmented or indistinctly segmented, without dorsal tergites. No prosome-urosome division present. Anus positioned posteriorly or on dorsal surface posterior to genital apertures. Caudal rami absent, or reduced and armed with at most 1 seta or spine. Rostrum not developed, usually absent. Antennule small, 1- to 3-segmented, armed with few small setae. Antenna up to 4-segmented, usually 2-segmented; terminal segment forming claw, or tipped with 1 or 2 spines or processes. Labrum unarmed or armed with 2 to 8 processes or setiform elements. Mandible absent. Maxillule bilobed, armed with 1 to 3 (usually 2) apical setae or processes on inner lobe and 0 to 5 (usually 2 or 3) apical setae or processes on outer lobe. Maxilla robust, unguiform, 2-segmented; proximal segment unarmed; distal segment terminating in strong claw, with 1 small seta proximally on posterior surface. Maxilliped absent. Legs 1-4 consisting of 2-segmented, unarmed protopod and rudimentary exopod and endopod; intercoxal plates absent. Leg 5 absent.   
Male: Unknown.  
 Type species. bnterçpsẚs sphẚnx Aurivillius, 1885 by original monotypy.   
 Remarks. Copepods of the genus bnterçpsẚs are associated with solitary and compound ascidians. Ooishi (2009a) recognized 11 species as valid in bnterçpsẚs and Kim I.H. & Moon (2011) subsequently described a new species of this genus. In the present work, we add five additional new species. The major taxonomic characters that can be used to differentiate between these 17 species include the distal armature of the caudal rami, the segmentation and setation of the antennule, the terminal armature of the antenna, the ornamentation of the labrum, and the armature of the maxillule (see Table 7).   
 Generic names ending in –opsis are feminine so in Table 7 we have amended the following names accordingly: bnterçpsẚs arctẚcus Marchenkov, 1994 becomes bK arctẚca, bK capẚtulatus Illg & Dudley, 1980 becomes bK capẚtulata, bK geçrgẚanus Schellenberg, 1922 becomes bK geçrgẚana, bK nudus Kim I.H. & Moon, 2011 becomes bK nudaI bK çnychçphçrus Schellenberg, 1922 becomes bK çnychçphçra, and bK superbus Illg & Dudley, 1980 becomes bK superba.
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 265-269, DOI: 10.11646/zootaxa.4978.1.1, http://zenodo.org/record/4820443