Konarus cheiris, Bamber, Roger N., 2006

Bamber, Roger N., 2006, Shallow water tanaidaceans (Crustacea: Peracarida: Tanaidacea) from New Caledonia and the Loyalty Islands, Zootaxa 1108, pp. 1-21 : 7-12

publication ID	https://doi.org/ 10.5281/zenodo.171481
DOI	https://doi.org/10.5281/zenodo.6256437
persistent identifier	https://treatment.plazi.org/id/2B757635-7B32-FF85-FEF0-5E92E9CBF0A4
treatment provided by	Plazi
scientific name	Konarus cheiris
status	sp. nov.

Treatment

Konarus cheiris View in CoL sp. nov.

Figs. 3–5 View FIGURE 3 View FIGURE 4 View FIGURE 5

Material: 1 female, holotype ( MNHN.Ta895), 1 female, paratype ( MNHN.Ta896), sample LF3 ‘83’, Baie de Santal, Loyalty Islands, 20º07.27’S 167º07.34’E, 12 m depth on red algae. 2 females, paratypes (NHM 2005.216–217) on Sargassum , 1 female, robust morph, paratype ( MNHN.Ta897) on Halimeda, Lagon, Ilot Maitre , New Caledonia, 22º19.41’S 166º20.89’E (Stn. 99), 20 m depth 9/11/95; all coll. Ichiro Takeuchi.

Description of female: body ( Figure 3 View FIGURE 3 A) 5.9 times as long as wide, holotype 2.6 mm long. Cephalothorax subrectangular, 1.06 times as long as wide, as long as pereonites 1 and 2 together, with slight rounded rostrum, triangular eyelobes conspicuous, eyes present and black, paired setae at posterior of eyelobes and single seta midlaterally; dorsal cuticular line distinguishing second thoracomere at posterior of cephalon. Six free pereonites; pereonites 1 and 6 subequal, shortest, pereonites 2 to 5 longer, subequal, (all pereonites respectively 2.25, 1.64, 1.9, 1.52, 1.57 and 2.14 times as wide as long). Pleon of five free subequal pleonites bearing pleopods; each pleonite about four times as wide as long. Pleotelson ( Figure 3 View FIGURE 3 B) rectangular, longer than last two pleonites together, just more than twice as wide as long, with one posteromedial plumose seta on each side, and two simple and two fine distal setae.

Antennule ( Figure 3 View FIGURE 3 C) of three articles, proximal article tumid, 1.9 times as long as wide, 2.5 times as long as distal two articles together; second article just wider than long, distal outer and paired inner setae longer than article; third article twice as long as wide and 1.5 times as long as second article, with five distal setae and one aesthetasc.

Antenna ( Figure 3 View FIGURE 3 D) of seven articles, proximal article compact, naked; second and third articles as long as wide, with single dorsal distal seta; fourth article longest, as long as second and third articles together and 2.3 times as long as wide; fifth article 0.5 times as long as fourth; sixth article minute; fifth and sixth articles each with three distal setae.

Mouthparts. Labrum ( Figure 3 View FIGURE 3 E) distinct, rounded, setose. Left mandible ( Figure 3 View FIGURE 3 F) with crenulate lacinia mobilis, proximal crenulation on pars incisiva, pars molaris elongate, blunt; right mandible ( Figure 3 View FIGURE 3 G) similar but without lacinia mobilis, pars incisiva entirely crenulate. Maxilliped ( Figure 3 View FIGURE 3 L) palp first article naked, second article with one outer and four inner setae, distalmost inner seta nearly reaching distal margin of third palp article; third and fourth articles with filtering rows of six and seven setae respectively, third article with two further inner distal setae and single outer seta, fourth article with outer seta; basis ( Figure 3 View FIGURE 3 K) with five long setae extending to third palp article; each endite ( Figure 3 View FIGURE 3 L) distally with single outer seta, single inner seta and three elongate spatulate spines, and finely setose outer ventral face. Labium ( Figure 3 View FIGURE 3 H) wide, distally finely setose, without palp. Maxillule ( Figure 3 View FIGURE 3 I) with nine distal spines, setose outer margin, and row of setules on inner distal face; palp distinct, with two distal setae. Maxilla ( Figure 3 View FIGURE 3 J) small, simple; epignath ( Figure 3 View FIGURE 3 M) elongate, slender, distally setose.

Cheliped ( Figure 4 View FIGURE 4 A) stout, with elongate basis 1.8 times as long as wide, mesial dorsodistal slender tubercle bearing seta; merus triangular with eight ventral setae; carpus 1.4 times as long as wide, outer margin extended ventrodistally and distally to form cuff around base of propodus; propodus 1.6 times as long as wide, fixed finger short with two ventral and four inner setae, cutting edge crenulate, terminal spine subdistal; dactylus simple with proximal seta as long as dactylus.

Pereopod 1 ( Figure 4 View FIGURE 4 B) longer than other pereopods, coxa naked; basis slender, 4 times as long as wide, with proximal seta longer than basis width; ischium half as long as wide with one seta; merus half as long as carpus, naked; carpus with three distal setae, longest of which is 0.8 times length of propodus; propodus as long as carpus, with four distal setae; dactylus slender, naked, extending into longer slender unguis, the two together 1.4 times as long as propodus.

Pereopod 2 ( Figure 4 View FIGURE 4 C) more compact, with coxa, basis and ischium similar to those of pereopod 1; merus as long as carpus, merus with small ventrodistal seta, carpus with single ventrodistal seta; propodus just longer than carpus and shorter than its longest distal seta; dactylus and short unguis as long as propodus.

Pereopod 3 ( Figure 4 View FIGURE 4 D) similar to pereopod 2, but basis without proximal seta, carpus with shorter ventral spine.

Pereopod 4 ( Figure 4 View FIGURE 4 E) basis stout, 1.6 times as long as wide; ischium minute, naked; merus, carpus and propodus subequal; merus with one short ventrodistal seta on each side; carpus with paired outer and inner distal molariform spines and fine combrows of setules; propodus with ventrodistal molariform spine and three dorsodistal setae, two of which are as long as dactylus plus unguis; dactylus and unguis fused into an claw, curved. Pereopod 5 ( Figure 4 View FIGURE 4 F) as pereopod 4 but without molariform spine on propodus. Pereopod 6 ( Figure 4 View FIGURE 4 G) as pereopod 5.

Pleopods ( Figure 4 View FIGURE 4 H) all alike, with single dorsal plumose seta on basis; endopod with single inner plumose seta.

Uropod ( Figure 3 View FIGURE 3 B) biramous, basis naked; exopod of two segments, just longer than proximal endopod segment, outer distal seta longer than inner distal seta; endopod of six segments each about twice as long as wide.

Robust morph: the specimen from “Station 99” taken on Halimeda was of a more compact morphology ( Figure 5 View FIGURE 5 ), but otherwise indistinguishable. The specimen is 2.9 mm long, 4.1 times as long as wide; cephalothorax 0.95 times as long as wide, longer than pereonites 1 to 3 together; pereonites 1 to 3 subequal, shortest, pereonites 4 and 5 longest, subequal, pereonite 6 half as long again as pereonite 3 (all pereonites respectively 3.64, 4.0, 3.8, 2.11, 2.36 and 2.89 times as wide as long); each pleonite about 6 times as wide as long.

Etymology: from the Greek cheiris , a glove or sleeve (noun in apposition), alluding to the cufflike overlap of the distal carpus of the cheliped.

Remarks: There is general similarity between the genera within the Leptocheliidae , a group of taxa showing, inter alia, numerous (three or more) segments in the uropod endopod. Their distinctions were discussed by Lang (1973), Sieg (1986), Guţu (1996: Intermedichelia ), Bamber and Bird (1997), Bird and Bamber (2000) and Larsen and Wilson (2002). Of the genera closest to (and including) Leptochelia , Pseudonototanais is distinct in having narrow bases on pereopods 4 to 6 and only a weak ventral seta on antenna article 2; Pseudonototanais and Intermedichelia have only two to three distal setae on the maxilliped basis; Pseudonototanais and Pseudoleptochelia have attenuated uropod endopod articles; female Intermedichelia have lateral spinelike apophyses on the third pereonite.

With five maxilliped basis setae, shorter uropod endopod segments and swollen bases to pereopods 4 to 6, Konarus is closest to Leptochelia . It has, however, setae rather than stout spines on the merus of the pereopods, and is without the ventral spine on the second antenna article, indeed without the dorsal spines on the second and third articles found in that genus (as well as in Pseudoleptochelia and Intermedichelia ). With its elongate distal maxilliped endite spines, the hooded chela, the swollen first antennule peduncle article and the indication of the distinction of the second thoracomere from the cephalon, the present material is considered to represent a distinct genus. The remaining features of its anatomy are entirely consistent with the known genera of this family. Specimens are readily recognized by the fat first article of the antenna peduncle.