Pogonura rugosa gen. et, 2020

Komeda, Sota & Ohtsuka, Susumu, 2020, New genus and species of calanoid copepods (Crustacea) belonging to the group of Bradfordian families collected from the hyperbenthic layers off Japan, ZooKeys 951, pp. 21-35 : 21

publication ID	https://dx.doi.org/10.3897/zookeys.951.49990
publication LSID	lsid:zoobank.org:pub:D6B82671-C4A8-4846-AA72-E59B17C19E0C
persistent identifier	https://treatment.plazi.org/id/6C0D4F63-BDD0-41A7-88D3-8D7D2EC9BB3C
taxon LSID	lsid:zoobank.org:act:6C0D4F63-BDD0-41A7-88D3-8D7D2EC9BB3C
treatment provided by	ZooKeys by Pensoft
scientific name	Pogonura rugosa gen. et
status	sp. nov.

Treatment

Pogonura rugosa gen. et sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Material examined.

Holotype. One ♀; whole body in vial (NSMT-Cr 27413). Allotype. One ♂, dissected and appendages mounted on glass slide, body in vial (NSMT-Cr 27414). Paratype. One ♀, dissected and appendages mounted on glass slide, body in vial (NSMT-Cr 27415). Body length. Adult female: 1.69 mm (holotype), 1.73 mm (paratype). Adult male: 1.71 mm (allotype).

Description of adult female.

Body (Fig. 1A, B View Figure 1 ) weakly sclerotized; cephalosome incompletely fused to first pediger with future line dorsally and laterally visible; fourth and fifth pedigers completely fused; posterolateral corners of prosome extending posteriorly, rounded and covering one-third of genital double-somite. Rostrum (Fig. 1C View Figure 1 ) produced ventrally, with pair of frontal filaments distally. Urosome (Fig. 1D, E View Figure 1 ) 4-segmented; genital double-somite symmetrical with pair of seminal copulatory pores and seminal receptacles (Figs 1D, E View Figure 1 , 8 View Figure 8 ); seminal copulatory pores ovaliform; seminal receptacles narrow near the seminal copulatory pores and becoming semicircular in the inner part; genital operculum semicircular, ventrally located midway; two spiniform setae located ventrolaterally, as long as genital double-somite (Figs 1D, E View Figure 1 , 8 View Figure 8 , indicated by arrows). Caudal rami (Fig. 1D-F View Figure 1 ) symmetrical, about 1.2 times as long as wide; seta I reduced, short seta II dorsally, seta III-VI long, short seta VII ventrally.

Antennule (Fig. 1F View Figure 1 ) 24-segmented, exceeding posterior border of third pediger; ancestral segments II-IV, X-XI and XXVII-XXVIII fused; armature as follows: I-2, II-3 (2+1ae?), III-2+1ae, IV-2, V-2, VI-2, VII-2+1ae, VIII-2, IX-2, X-2, XI-2+1ae, XII-1, XIII-1, XIV-2+1ae, XV-2, XVI-2+1ae, XVII-1, XVIII-2, XIX-1, XX-2, XXI-1+1ae, XXII-1, XXIII-1, XXIV-1+1, XXV-1+1, XXVI-1+1, XXVII-2, and XXVIII-2+1ae.

Antenna (Fig. 2A, B View Figure 2 ) with 1 seta and row of long setules on coxa; basis with 2 setae at inner distal corner; exopod 7-segmented; ancestral segments II-IV fused and VI-VII incompletely fused without suture line, setal formula of 1, 1-1-1, 1, 1-1, 1, 0, 3; fused segments II-IV having row of fine setules along outer distal margin; endopod 2-segmented, proximal segment with 2 setae, distal segment bilobed, bearing 8 setae on inner lobe and 6 setae and short setules on outer lobe.

Mandible (Fig. 2C-E View Figure 2 ) having gnathobase with triangular ventralmost tooth, 5 chitinized teeth, 16 long setules and dorsal seta; palp with basis having 3 inner setae; endopod 2-segmented; proximal endopodal segment bearing 1 seta, distal segment with 9 setae; exopod 5-segmented, with setal formula of 1, 1, 1, 1, 2.

Maxillule (Fig. 2F-H View Figure 2 ) with 9 terminal and 4 posterior setae on praecoxal arthrite; coxal endite with 3 setae; coxal epipodite with 9 setae; proximal and distal basal endites having 3 and 5 setae, respectively; proximal and distal segments of endopod with 3 and 8 setae, respectively; exopod with 8 setae; rows of setules on arthrite, basis and exopod.

Maxilla (Fig. 3A, B View Figure 3 ) with 2 praecoxal and 2 coxal endites having 5, 3, 3, and 3 setae, respectively; basis with 1 well-chitinized and 3 slender setae; endopod 3-segmented, with 3 sclerotized and 5 brush-like setae of various length, proximal segment with 3 brush-like setae (1 slender, 1 short and stout, 1 moderate), middle segment with 2 brush-like setae (1 short and stout, 1 moderate), distal segment with 3 sclerotized setae.

Maxilliped (Fig. 3C, D View Figure 3 ) with syncoxal endites having 1, 2, 3 and 3 setae; row of fine setules at syncoxal distal corner and along basal inner margin; basis with 3 setae midway; first endopodal segment almost incorporated into basis; first to sixth endopodal segments with 2, 4, 4, 3, 3+1, and 4 setae, respectively.

Seta and spine formulae of legs 1-4 are shown in Table 1 View Table 1 . Leg 1 (Fig. 4A View Figure 4 ) with medial long setules on coxa and basis; von Vaupel Klein organ ( Vaupel Klein 1972) distinct on anterior surface of endopod; distal seta of basis twice as long as endopod; distal segment of exopod with outer row of setules. Leg 2 (Fig. 4B View Figure 4 ) with coxa having row of fine setules midway and row of fine spinules at distal outer corner; first exopodal segment with 1 large and 1 minute prominence on posterior surface; distal endopodal segment having 3 large prominences on posterior surface. Leg 3 (Fig. 4C View Figure 4 ) with basis having row of minute setules at base of endopod on posterior surface; second endopodal segment having 3 large prominences on posterior surface. Leg 4 (Fig. 4D View Figure 4 ) with first and second segments of both rami having small prominences on posterior surface.

Leg 5 (Fig. 4E View Figure 4 ) uniramous; coxae and intercoxal sclerite fused to form common base; basis broad, about 1.3 times as long as wide; exopod 1-segmented, ca. 4.4 times as long as wide, with 3 lateral processes and 1 terminal bipinnate spine.

Description of adult male.

Body (Fig. 5A, B View Figure 5 ) weakly sclerotized like the female; fusion between cephalosome and first pediger and between fourth and fifth pedigers similar to those of female; posterolateral corners of prosome rounded, not extending posteriorly. Rostrum similar to that of female. Urosome (Fig. 5C, D View Figure 5 ) 5-segmented; gonopore located on the left side; small plate covering around gonopore; caudal rami similar to those of female.

Antennule asymmetrical in fusion patterns. Right antennule (Fig. 5E View Figure 5 ) 22-segmented; ancestral segments II-IV, X-XII, XXII-XXIII and XXVII-XXVIII fused; armature elements as follows: I-1, II-3 (2+1ae?), III-1+1ae, IV-2+1ae,V-2+2ae, VI-1+ae, VII-2+1ae, VIII-2, IX-1+1ae, X-1, XI-2+1ae, XII-2, XIII-1, XIV-2, XV-1, XVI-2+1ae, XVII-1, XVIII-3, XIX-2, XX-2, XXI-2, XXII-1, XXIII-1, XXIV-1+1, XXV-1+1, XXVI-1+1, and XXVII-1, and XXVIII-2+1ae. Left antennule (Fig. 5F View Figure 5 ): 23-segmented; ancestral segments II-IV, X-XII and XXVII-XXVIII fused; armature elements as follows: I-1+1ae, II-2+1ae, III-2+ae, IV-2+1ae, V-3, VI-3, VII-2+1ae, VIII-2, IX-2, X-2, XI-2+1ae, XII-1, XIII-1, XIV-2, XV-1, XVI-1, XVII-1, XVIII-1, XIX-1, XX-1, XXI-1, XXII-1, XXIII-1, XXIV-1, XXV-1+1, XXVI-1+1, XXVII-2, and XXVIII-2.

Other appendages similar to those of the female, except leg 5.

Right leg 5 (Fig. 6A, B View Figure 6 ) uniramous; endopod absent; coxa small; basis robust, 2.2 times as long as wide; exopod 2-segmented, proximal segment plate-like, distal segment spiniform. Left leg 5 (Figs 6A-G View Figure 6 , 7 View Figure 7 ) biramous; coxa small; basis smaller than right basis and slender, 2.5 times as long as wide; endopod 1-segmented, plate-like, and having baculiform plate and semicircular plate; exopod 2-segmented and highly complex in structure; proximal segment of exopod having proximal plate without armament ( “pp1” in Figs 6 View Figure 6 , 7 View Figure 7 ) and distal plate, larger, semicircular plate with 4 setules ( “pp2” in Figs 6 View Figure 6 , 7 View Figure 7 ); distal segment of exopod elongate, 9.0 times as long as proximal segment; proximal part of distal segment having 6 medial spinules ( “ms” in Figs 6 View Figure 6 , 7 View Figure 7 ), lateral spinule ( “ls1” in Figs 6 View Figure 6 , 7 View Figure 7 ) and anterior plate with 9 spinules ( “ap1” in Figs 6 View Figure 6 , 7 View Figure 7 ), midpoint of segment having thin, curved plate ( “ap2” in Figs 6 View Figure 6 , 7 View Figure 7 ) anteriorly, and distal part having spinule ( “ls2” in Figs 6 View Figure 6 , 7 View Figure 7 ) and thin plate with crest ( “tp” in Figs 6 View Figure 6 , 7 View Figure 7 ).

Remarks.

Pogonura rugosa gen. et sp. nov. has a symmetrical pair of spiniform setae on the genital double-somite of the female (Figs 1E View Figure 1 , 8 View Figure 8 ). Diaixis centrura Connell, 1981, D. gambiensis Andronov, 1979, and D. trunovi Andronov, 1979 also have armatures on the counterparts [figs 39 and 94 in Andronov (1979); fig. 4 in Connell (1981)]; however, those of Diaixis are asymmetrical and consist of fine spinules.

Etymology.

The specific name of the new species is derived from a Latin word rugosa , meaning “rugose”, to denote leg 5 of the adult male with many foliaceous armatures.