Paraleptognathia brachiata ( Hansen, 1913 ) 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 : 22-25

Paraleptognathia brachiata ( Hansen, 1913) new combination ( Figs 7 , 8 )

Synonymy: Leptognathia brachiata Hansen, 1913

Material examined: syntypes ZMUC CRU 3738 RV ”Ingolf” St. 25, 63° 30´N 54° 25´W, 582 fm (1065 m), six females (one dissected), one juvenile male, one neuter , ZMUC CRU 5877 RV ”Ingolf” St. 24, 63° 06´N 56° 00´W, 1199 fm (2194 m), four females, one neuter .

Diagnosis: Cheliped carpal shield triangular, pointed. Maxilliped basis long. Uropod basal article about three times as long as wide.

Description: non­ovigerous female. Body ( Fig. 7a, b ): long, about 7.5 times longer than wide. Body length 1.6 to 3.6 mm. Cephalothorax ( Fig. 7a, b ): egg­shaped, about 1.3 times longer than broad, shorter than pleon. Pereon ( Fig. 7a, b ): pereonite 1 as long as pereonite 6; pereonite 5 longer than pereonite 6 and shorter than pereonite 4; pereonites 2, 3, 4 equal long. Pleon ( Fig. 7a, b ): pleonites 1 and 3 equal in length and longer than the others; pleonites 2, 4 and 5 subequal; each pleonite with lateral simple seta.

Antennule ( Fig. 7c ): article 1 longest with one simple distal seta; article 2 with one long and one short distal setae; article 3 shortest with one distal simple short seta; article 4 with five terminal setae.

Antenna ( Fig. 7e ): article 1 short, semifused to cephalothorax (not illustrated); article 2 as long as broad, with one short spiniform seta; article 3 with one dorsal simple seta; article 4 with a constriction at midlength, two long terminal simple setae; article 5 with one simple terminal seta; article 6 shortest, with four terminal simple setae.

Labrum ( Fig. 8b ): hood­shaped, with a row of setules at the lateral margins.

Mandible ( Fig. 8c ): lacinia mobilis broad and pointed; right mandible broken during dissection.

Maxillula ( Fig. 8a ): endite with five rows of setules dorsally and two pinnate, two short and five smooth terminal spiniform setae.

Maxilla ( Fig. 8f ): rectangular, with no special features.

Labium ( Fig. 8d ): composed of two triangular lobes, with one seta distally on each lobe.

Maxilliped ( Fig. 8g ): basis long, tongue­shaped; basal setae were not observed.

Epignath ( Fig. 8e ): with no special features.

Cheliped ( Fig. 7h ): basis shorter than carpus; merus with one simple ventral seta; carpus with one ventral and one dorsal setae, carpal shield well­developed, pointed, triangular; propodus smooth with three teeth on cutting edge; dactylus smooth, about 0.6 length of propodus.

Pereopod 1 ( Fig. 7i ): coxa naked; basis about three times as long as broad, with one simple dorsal seta; ischium short, with one simple seta; merus as long as carpus, smooth, with one spiniform seta; carpus smooth, with two spiniform setae; propodus with small terminal spine, and a thin short seta dorsally and a short spiniform seta ventrally; dactylus smooth, about as long as unguis.

Pereopod 2 ( Fig. 7j ): as pereopod 1, except carpus longer than merus, with three spiniform setae.

Pereopod 3 ( Fig. 7k ): as pereopod 1, except basis naked and carpus with three spiniform setae.

Pereopod 4 ( Fig. 7l ): basis about 3.5 times longer than broad, with one ventral simple seta; ischium short with two simple setae; merus smooth, shorter than carpus, with two spiniform setae; carpus smooth, with three spiniform setae; propodus with terminal spine and two terminal spiniform setae; dactylus longer than unguis.

Pereopod 5 ( Fig. 7m ): as pereopod 4, except basis with two ventral simple setae.

Pereopod 6 ( Fig. 7n ): as pereopod 5, except basis naked and one short and two long spiniform setae on carpus.

Pleopods ( Fig. 7f ): basal article triangular, exopod with seven simple long setae, endopod with six simple setae.

Uropods ( Fig. 7g ): basal article of the uropod is about three times as long as wide. Exopod half as long as article 1 of endopod; exopod article 1 with one short distal seta; article 2 with one short and one long terminal setae. Endopod article 1 with two distal short simple setae, article 2 with five terminal setae.

Ovigerous female body length 2.7 to 3.0 mm.

Juvenile male body length 2.8 mm. Antennule ( Fig. 7d ): article 1 longest with one distal simple seta; article 2 as long as articles 4 and 5 together, with one distal seta; article 3 with one distal simple seta; article 4 shortest, naked; article 5 with five terminal setae.

Manca up to 1.5 mm.

Distribution: North Atlantic Ocean, Davis Strait off southwest Greenland.

Type locality: Davis Strait, RV ”Ingolf” St. 25, 63° 30´N 54° 25´W, 582 fm (1065 m) .

Remarks: this species has a very prominent oval carpal shield on the cheliped, which is an outstanding character. The length of the basal article of the uropod is about three times as long as wide, which also makes it very easy to distinguish from other species, in which the basal article is less than two times as long as wide.

Figures

FIGURE 7. Paraleptognathia brachiata ZMUC CRU 3738 a. Body dorsal view b. Body lateral view. Scale bar 1mm c. Antennule, d. Antennule juvenile male, e. Antenna, f. Pleopod, g. Uropod, h. cheliped, i. Pereopod 1, j. Pereopod 2, k. Pereopod 3, l. Pereopod 4, m. Pereopod 5, n. Pereopod 6. Scale bar 0.25 mm.

FIGURE 8. Paraleptognathia brachiata ZMUC CRU 3738 a. Maxillula, b. Labrum, c. Mandibles, d. Labium, e. Epignath, f. Maxilla, g. Maxilliped. Scale bar 0.1 mm.