Paraleptognathia tenuichela, 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 : 56-59

Paraleptognathia tenuichela n. sp. ( Figs 26 , 27 )

Material examined: Six individuals. Holotype ZMH K­40631 RV ”Meteor” 48 St. 350, one female . Paratypes ZMH K­40632 RV ”Meteor” 48 St. 341, two females (1 dissected) , ZMH K­40633 RV ”Meteor” 48 St. 346, one female , ZMH K­40364 RV ”Meteor” 48 St. 346, one female .

Diagnosis: Chela long and slender, rami of pleopods long and slender, no plumose seta.

Description: non­ovigerous female. Body ( Fig. 26a, b ): long, about 9.5 times longer than broad. Body length 1.4 to 3.3 mm. Cephalothorax ( Fig. 26a, b ): about 1.3 times longer than broad. Pereon ( Fig. 26a, b ): pereonite 1 as long as 6; pereonites 2, 3 and 5 subequal and longer than 1; pereonite 4 longest. Pleon ( Fig. 26a, b ): pleonites subequal, pleotelson pentameral.

Antennule ( Fig. 26c ): article 1 longest, with one long and four short setae; article 2 with one long simple and one short simple setae; article 3 shortest with two terminal simple setae; article 4 with four terminal setae.

Antenna ( Fig. 26d ): article 1 short, semifused to cephalothorax; article 2 as long as wide, with one short spiniform dorsal seta; article 3 with one simple distal seta; article 4 longest, with two distal simple long, two distal simple short setae; article 5 with one simple long seta distally; article 6 shortest, with two terminal simple setae.

Labrum ( Fig. 27d ): hood­shaped, with row of setules at lateral and apical margins.

Mandible ( Fig. 27c ): well calcified; pars molaris bent ventrally; lacinia mobilis tipped by two tubercles.

Maxillula ( Fig. 27a ): endite with three rows of ventral setules, with eight simple terminal spiniform setae.

Maxilla ( Fig. 27b ): triangular, elongated, smooth.

Labium ( Fig. 27e ): composed of two lobes with three short simple setae at distal outer margin.

Maxilliped ( Fig. 27f ): endites with distal tubercles.

Epignath: lost during dissection.

Cheliped ( Fig. 26g ): basis as long as carpus; merus naked; carpus with simple ventral seta; carpal shield weak, poorly developed; propodus long, slender, about three times as long as broad, three teeth at cutting edge, one long and one short ventral setae; dactylus slender and smooth.

Pereopod 1 ( Fig. 26h ): coxa naked; basis about four times as long as broad; ischium short, with one simple setae; merus with one spiniform seta; carpus with two spiniform setae; propodus with ventral row of spinules, a terminal spine, and one spiniform seta; dactylus smooth.

Pereopod 2 ( Fig. 26i ): as pereopod 1, except carpus with three spiniform setae, propodus with simple dorsal seta.

Pereopod 3 ( Fig. 26j ): as pereopod 1, except carpus with three spiniform setae.

Pereopod 4 ( Fig. 26k ): basis about four times as long as broad, with two simple setae; ischium short, with one simple seta; merus with two spiniform setae; carpus with three spiniform setae; propodus with distal spine, one dorsal simple and four terminal spiniform setae; dactylus with no special features.

Pereopod 5 ( Fig. 26l ): as pereopod 4, except basis five times as long as broad, with three simple setae, carpus with four spiniform setae.

Pereopod 6 ( Fig. 26m ): as pereopod 4, except basis five times as long as broad, with only one simple seta, merus with three spiniform setae, carpus with four spiniform setae, propodus lacks dorsal simple seta.

Pleopods ( Fig. 26f ): exopod lacks plumose seta. Exopod with five long simple setae; endopod with four simple long setae.

Uropods ( Fig. 26e ): exopod half the length of article 1 of endopod. Exopod article 1 with one simple seta, article 2 with one terminal simple seta. Article 1 of endopod with two distal simple setae, article 2 with four terminal setae.

Type locality: South Atlantic Ocean , Angola Basin, RV ”Meteor” 48 St. 350, 16° 13.3´S 05° 26.8´E– 16° 14.9´S 05° 26.7´E, 5389 m .

Etymology: the name refers to the thin (Latin: tenuis) and slender chela.

Distribution: South Atlantic Ocean, Angola Basin.

Remarks: this species has chela and rami of pleopods very slender; also pleopods lacks the plumose seta on the exopod. These ”unusual” characters make it easy to distinguish from other Paraleptognathia , but there is no doubt that this species belongs to the Paraleptognathia genus.

Figures

FIGURE 26. Paraleptognathia tenuichela ZMH K­40631 a. Body, dorsal view, b. Body, lateral view. Scale bar 1mm. ZMH K­40632 c. Antennule, d. Antenna, e. Uropod, f. Pleopod, g. Cheliped, h. Pereopod 1, i. Pereopod 2, j. Pereopod 3, k. Pereopod 4, l. Pereopod 5, m. Pereopod 6. Scale bar 0.25 mm.

FIGURE 27. Paraleptognathia tenuichela ZMH K­40632 a. Maxillula, b. Maxilla, c. Mandibles, d. Labrum, e. Labium, f. Maxilliped. Scale bar 0.1 mm.