Notopygus minutispinatus, Kim & Boxshall, 2020

Kim, Il-Hoi & Boxshall, Geoff A., 2020, Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata), Megataxa 4 (1), pp. 1-6 : 399-400

publication ID

https://doi.org/ 10.11646/megataxa.4.1.1

DOI

https://doi.org/10.5281/zenodo.5699867

persistent identifier

https://treatment.plazi.org/id/03C487CB-EEDF-3BBA-FCEF-F966FC1FF9F8

treatment provided by

Plazi

scientific name

Notopygus minutispinatus
status

gen. et sp. nov.

Notopygus minutispinatus gen. et sp. nov.

( Figs. 265 View FIGURE 265 , 266 View FIGURE 266 )

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21335 ) , paratypes (2 intact ♀♀, MNHN-IU-2014-21336), anddissectedparatype (♀, figured) from Pyura stolonifera (Heller, 1878) (MNHN-IT-2008-7777 = MNHN S2/ PUY/XXX, lames 306), MRAC-ULB (Musée Royal de l’Afrique Centrale et Université Libre de Bruxelles), Inhaca Is, Mozambique (26°03 Ś, 32°54 É), depth 10-20 m, 07 August 1969.

Etymology. The specific name is derived from the Latin minut (=small) and spin (=spine) and refers to the small size of the apical spines on the caudal ramus.

Descriptionoffemale. Body ( Fig. 265A View FIGURE 265 ) 4.36 mm long: prosome 3.60 mm long, with well-defined dorsal cephalic shield and bulbous metasome. Cephalosome to second pedigerous somite divided by weak constrictions; third and fourth pedigerous somites fused to form greatly inflated brood pouch. Free urosome ( Fig. 265B View FIGURE 265 ) 5- segmented,graduallynarrowingposteriorly:genitalsomite 270×502 μm, with copulatory pore at anterior quarter on ventral surface; 4 abdominalsomites 364×393, 327×335, 182×276, and 167×247 μm, respectively. Caudalramus ( Fig. 265C View FIGURE 265 ) about 4.1 timeslongerthan wide (264×64 μm), with nearly parallel margins in proximal third but graduallynarrowing in distal two-thirds: armedwith 2 small setae and 4 minute distal spines; 2 setae positioned at 34 and 63% of ramus length, both setae about half as long as width of ramus at base; distal spines blunt, at most 13 μm long, scarcely visible at low magnification.

Coxa Basis Exopod Endopod
Leg 1 0-1 Legs 2 & 30-1 Leg 4 0-1 1-I 1-0 1-0 I-1; I-1; III, I, 4 1-1; 1-1; 3, 1, 5 1-1; 1-1; 3, 1, 5 0-1; 0-1; 1, 2, 3 0-1; 1, 2, 5 0-1; 1, 2, 4

Rostrum ( Fig. 265D View FIGURE 265 ) about 110×136 μm, gently tapering proximally and steeply tapering in distal third. Antennule ( Fig. 265E View FIGURE 265 ) 345 μmlong, 9-segmented; first and second segments much broader than distal segments; fifth segment subdivided on posterior side; armature formula 3, 17, 5, 5, 4, 2+aesthetasc, 2, 2+aesthetasc, and 7+aesthetasc; setae generally small, all naked. Antenna ( Fig. 265F View FIGURE 265 ) 4-segmented; coxa unarmed; basis 127×69 μm, with 2 vestigial setae on small knob (representing exopod) subdistally on outer margin; first endopodal segment 90×64 μm, with 1 small seta on inner margin; compound distal endopodal segment about 3.2 times longerthanwide (120×38 μm): armedwith 7 setae arranged as 1, 3, 1, and 2 plus terminal claw about 76 μm long, strongly curved at tip.

Labrum asin N. trispinatus gen. et sp. nov. Mandible ( Fig. 265G View FIGURE 265 ) with 5 teeth and 1 small seta on coxal gnathobase: basis with 1 seta and row of minute spinules on subdistal medial margin: exopod 3-segmented and armed with 4 subequal setae (1, 1, and 2 setae on firsttothird segments): endopod 2-segmented; first segment with 4 unequal setae on medial margin and minute spinules scattered over ventral surface; second segment narrower than first, armed with 10 setae of various lengths. Paragnath ( Fig. 265H View FIGURE 265 ) as small lobe with setules on medial margin, minute spinules mediodistally, and small rounded outer process distally. Maxillule ( Fig. 265I View FIGURE 265 ) consisting of precoxa, coxa, basis, exopod and endopod: precoxa with 9 setae on arthrite; coxa with 1 seta on endite and 2 very unequal setae on epipodite; basis with 3 (2 long distal and 1 short proximal) setae on medial margin and row of several minute spinules near base of each distal seta; exopod with 3 setae distally and 1 minute vestigial seta between outer and middle setae; endopod with 3 equal setae. Maxilla ( Fig. 265J View FIGURE 265 ) 5-segmented; syncoxa with 9 setae arranged as 3, 1, 2, and 3; basis with 1 strong claw bearing setules along concave margin plus 2 unequal setae; endopod slender, with 1, 1, and 3 setae on first to third segments, respectively. Maxilliped ( Fig. 266A View FIGURE 266 ) incompletely 2-segmented; first segment with 9 setae medially; smallsecond segment with 2 equal apical setae.

Leg 1 ( Fig. 266B View FIGURE 266 ) with 3-segmented rami. Outer seta on basis small. Inner distal spine on basis 50 μm long, not extending to distalborder of first endopodal segment. First and second exopodal segments with dense tuft of setules on outer side. Legs 2–4 with 3-segmented exopods and 2- segmented endopods ( Fig. 266C, D View FIGURE 266 ); exopods longer than endopods. Outer seta on basis small as in leg 1. Outer setae on exopods attenuated and naked. All setae on third exopodal segment of legs 2–4 and 3 distal setae on second endopodal segment of leg 4 naked. Armature formula for legs 1–4 as follows:

Leg 5 ( Fig. 266E View FIGURE 266 ) 2-segmented: protopod broad, notarticulated at base, with 1 small seta on oblique outer margin and row of several spinules near base of exopod; free exopodal segment nearly rectangular and about 3.1 times longer than wide (182×58 μm); armed distally with slender spine (49 μm long) and thin seta (55 μm long); ornamented with 3 rows of minute spinules on dorsomedial surface.

Male. Unknown.

Remarks. Notopygus minutispinatus gen. et sp. nov. can be readily differentiated from its two congeners by the possession of 4 spines and 2 setae on the caudal ramus of the female, and by the 3-segmented endopod of leg 1. In contrast, thetype species N. unispinatus gen. et sp. nov. has only 1 spine and 5 setae on the caudal ramus, and N. trispinatus gen. et sp. nov. has 3 spines and 3 setae. Both these species have a 2-segmented endopod on leg 1 whereas in N. minutispinatus gen. et sp. nov. this ramus is 3-segmented.

MNHN

Museum National d'Histoire Naturelle

Kingdom

Animalia

Phylum

Arthropoda

SubPhylum

Tunicata

Class

Insecta

Order

Hymenoptera

Family

Ichneumonidae

Genus

Notopygus

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