Paraleptognathia benguela, 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 : 49-52

Paraleptognathia benguela n. sp. ( Figs 22 , 23 )

Material examined: 18 individuals. Holotype ZMH K­40618 RV ”Meteor” 48 St. 340, two females . Paratypes ZMB 27520, RV ”Meteor” 48 St. 346, three females , ZMUC CRU 3961 RV ”Meteor” 48 St. 325, two females , ZMH K­40619 RV ”Meteor” 48 St. 340, two females , ZMH K­40620 RV ”Meteor” 48 St. 345, one female , ZMH K­40621 RV ”Meteor” 48 St. 344, three females , ZMH K­40622 RV ”Meteor” 48 St. 340, one juvenile male, ZMH K­40623 RV ”Meteor” 48 St. 348, one female , ZMH K­40624 RV ”Meteor” 48 St. 325, one female , ZMH K­40625 RV ”Meteor” 48 St. 338, one female , ZMH K­ 40626 RV ”Meteor” 48 St. 348, one female , ZMH K­40627 RV ”Meteor” 48 St. 345, one female .

Diagnosis: Carpal shield well developed. Pereopod 1, 2, 3 with spinules on merus, carpus and propodus.

Description: non­ovigerous female. Body ( Fig. 22a, b ): long, about 7.3 times longer than broad. Body length 1.5 to 4.0 mm. Cephalothorax ( Fig. 22a, b ): about 1.3 times longer than broad. Pereon ( Fig. 22a, b ): pereonite 1 as long as pereonite 6; pereonite 5 as long as pereonite 2 and longer than 6, pereonite 4 longer than 2 and shorter than 3; pereonite 3 longest. Pleon ( Fig. 22a, b ): pleonites of equal length, pleotelson with pointed apex.

Antennule ( Fig. 22c ): article 1 longest, with one long and three short setae; article 2 with one long simple and two short simple setae; article 3 shortest, with two terminal simple setae; article 4 with five terminal setae.

Antenna ( Fig. 22d ): article 1 short, semifused to cephalothorax; article 2 as long as wide, with one short spiniform seta dorsally; article 3 with one simple distal seta; article 4 longest, with two distal simple long, two distal short and one short simple setae at midlength; article 5 with one simple long distal seta; article 6 shortest, with five terminal simple setae.

Labrum ( Fig. 23d ): hood­shaped, with row of setules on lateral margins.

Mandible ( Fig. 23c ): well calcified; pars molaris bent ventrally; lacinia mobilis spiniform and blunt.

Maxillula ( Fig. 23a ): endite with three rows of ventral setules, four rows of dorsal setules, with one simple and eight pinnate terminal spiniform setae.

Maxilla ( Fig. 23f ): rectangular, with a row of setules on distal edge.

Labium ( Fig. 23e ): composed of two triangular lobes with row of setules at distal edge.

Maxilliped ( Fig. 23g ): endites not fused, with a distal tubercle, basis tong­shaped.

Epignath ( Fig. 23b ): with no special features.

Cheliped ( Fig. 22g ): basis as long as carpus; merus with ventral simple seta; carpus with a ventral and a dorsal simple setae; carpal shield well developed, about one third of carpus; propodus smooth, with two teeth at cutting edge; dactylus smooth.

Pereopod 1 ( Fig. 22h ): coxa naked; basis twice as long as broad, with two simple setae; ischium short, with one simple seta; merus with a ventral and a dorsal row of spinules and one spiniform seta; carpus as long as merus, with a ventral and a dorsal row of spinules, and two spiniform setae; propodus with ventral and dorsal row of spinules, one terminal spine and terminal short spiniform seta; dactylus as long as propodus.

Pereopod 2 ( Fig. 22i ): as pereopod 1, except basis naked, merus and propodus lack dorsal rows of spinules, carpus with three spiniform setae.

Pereopod 3 ( Fig. 22j ): as pereopod 2, except carpus lacks dorsal rows of spinules, and only two spiniform setae.

Pereopod 4 ( Fig. 22k ): basis three times as long as broad, naked; ischium short, with one simple seta; merus with two spiniform setae; carpus with three spiniform setae; propodus with two terminal spiniform setae; dactylus with no special features.

Pereopod 5 ( Fig. 22l ): as pereopod 4, except basis with three simple setae; merus with two spiniform setae, propodus with three terminal spiniform setae, dactylus with larger spinules as in pereopod 4 and 6.

Pereopod 6 ( Fig. 22m ): as pereopod 4, except propodus with four terminal spiniform setae.

Pleopods ( Fig. 22f ): exopod with eight simple long setae, endopod with seven simple long setae.

Uropods ( Fig. 22e ): 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 simple setae; article 2 with six terminal setae.

Juvenile males body length 3.32 mm.

Mancas up to 1.5 mm.

Type locality: South Atlantic Ocean , Angola Basin, RV ”Meteor” 48 St. 340 18° 77.3´S 04° 41.2´E– 18° 19.4´S 04° 41.9´E, 5395 m .

Etymology: the name refers to the Benguela Current that flows on top of the Angola Basin.

Distribution: South Atlantic Ocean, Angola Basin.

Remarks: this species resembles P. bacescui but the presence of spinules on the merus and carpus of P1 to P3 on P. benguela distinguish them. A detailed analysis of the type of P. bacescui is needed to define these two species more properly.

Figures

FIGURE 22. Paraleptognathia benguela ZMH K­40618 a. Body, dorsal view, b. Body, lateral view. Scale bar 1mm. ZMH K­40619 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 23. Paraleptognathia benguela ZMH K­40619 a. Maxillula, b. Epignath, c. Mandibles, d. Labrum, e. Labium, f. Maxilla, g. Maxilliped. Scale bar 0.1 mm.