Paraleptognathia longiremis (Lilljeborg, 1864) Guerrero-Kommritz, 2004

Guerrero-Kommritz, Jürgen, 2004, A revision of the genus Paraleptognathia Kudinova-Pasternak, 1981 (Crustacea: Tanaidacea) and description of four new species, Zootaxa 481 (1), pp. 1-63 : 33-38

Paraleptognathia longiremis (Lilljeborg, 1864) new combination ( Figs 13 , 14 , 15 )

Synonymy: Akanthophoreus longiremis Sieg, 1986

Leptognathia longiremis (Lilljeborg, 1864)

Tanais longiremis Lilljeborg, 1864

Material examined: 21 individuals. ZMH K­40542 RV ”Polarstern” St. 31­6, 21 females.

Diagnosis: Propodus of pereopod 1 with a row of ventral spines.

Description: non­ovigerous female. Body ( Fig. 13a, b ): long, about eight times as long as broad. Body length 2.5 to 3.7 mm. Cephalothorax ( Fig. 13a, b ): about 1.4 times longer than broad. Pereon ( Fig. 13a, b ): pereonite 6 shortest, pereonite 1 longer than 6, shorter than 5, pereonite 5 as long as 4, pereonite 2 and 3 equal in length. Pleon ( Fig. 13a, b ): pleonites subequal; pleotelson rounded.

Antennule ( Fig. 14a ): article 1 longest with one long simple distal seta; article 2 with one distal simple seta; article 3 shortest, naked; article 4 with five terminal setae.

Antenna ( Fig. 14b ): article 1 short semifused to cephalothorax; article 2 as long as broad, with one short spiniform seta; article 3 with one dorsal simple seta, article 4 with two terminal long simple and one short simple setae, article 5 with one terminal simple seta; article 6 shortest, with four terminal simple setae.

Labrum ( Fig. 15a ): hood­shaped, with a row of setules on the distal margin.

Mandible ( Fig. 15c ): well calcified, pars molaris bent ventrally, lacinia mobilis spiniform.

Maxillula ( Fig. 15a ): endite with four rows of ventral setules, and one short, one pinnate and six simple terminal spiniform setae.

Maxilla ( Fig. 15f ): rectangular, smooth.

Labium ( Fig. 15e ): composed of two triangular lobes, with two distal simple setae on each lobe.

Maxilliped ( Fig. 15g ): endites not fused; no setae were observed on the basis.

Epignath ( Fig. 15b ): smooth, with no special features.

Cheliped ( Fig. 14a ): basis naked; merus with one ventral seta; carpus with two ventral and two dorsal simple setae and one tubercle near insertion of chela, carpal shield welldeveloped, rounded; propodus with three teeth at cutting edge; dactylus smooth.

Pereopod 1 ( Fig. 14f ): coxa naked; basis about 3.5 times longer than broad, naked; ischium short, with short simple seta; merus with one spiniform seta; carpus longer than merus, with two spiniform setae; propodus with a ventral row of short spines, one terminal spine and one spiniform distal seta; dactylus smooth; unguis sharp.

Pereopod 2 ( Fig. 14g ): as pereopod 1, except carpus with three spiniform setae and propodus smooth.

Pereopod 3 ( Fig. 14h ): as pereopod 1, except basis with setulose seta and propodus with a ventral and a dorsal row of spinules.

Pereopod 4 ( Fig. 14i ): basis about 3.5 times longer than broad, naked; ischium short, with a short simple seta; merus with two spiniform setae; carpus with three spiniform setae; propodus smooth, with four terminal spiniform setae and one terminal spine; dactylus as long as propodus; unguis sharp.

Pereopod 5 ( Fig. 14j ): as pereopod 4, except propodus with three terminal spiniform setae.

Pereopod 6 ( Fig. 14k ): as pereopod 4, except basis with two simple setae; carpus with four spiniform setae.

Pleopods ( Fig. 14e ): exopod with four simple long setae; endopod with five simple long setae.

Uropods ( Fig. 14d ): exopod less than half the length of endopod article 1. Exopod article 1 with one distal simple seta; article 2 with three terminal setae. Endopod article 1 naked; article 2 with four terminal setae.

Distribution: this species occurs in south and east Greenland.

Remarks: Paraleptognathia longiremis is very similar to P. gracilis and primary it was synonymized by Lang (1957) with this species. Paraleptognathia longiremis has a clear row of spinules on propodus of the pereopod 1. The chelipeds are different, the chela has no crenulation in P. longiremis , and propodus of P 1 has a row of spinules that is missing in P. gracilis . The observation of Hansen (1913) of a very long uropod is not present in all individuals. Most of the individuals found had a typical short Paraleptognathia uropod.

Figures

FIGURE 13. Paraleptognathia longiremis ZMH K­40542 a. Body dorsal view, b. Body lateral view. Scale bar 1mm.

FIGURE 14. Paraleptognathia longiremis ZMH K­40542 a. Cheliped, b. Antennule, c. Antenna, d. Uropod, e. Pleopod, f. Pereopod 1, g. Pereopod 2, h. Pereopod 3, i. Pereopod 4, j. Pereopod 5, k. Pereopd 6. Scale bar 0.25 mm.

FIGURE 15. Paraleptognathia longiremis ZMH K­40542 a. Maxillula, b. Epignath (Scale bar 0.25 mm), c. Mandibles, d. Labrum, e. Labium, f. Maxilla, g. Maxilliped. Scale bar 0.1 mm for a, c, d, e,f, g.