Paraleptognathia australis ( Beddard, 1886 ) 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 : 17-21

Paraleptognathia australis ( Beddard, 1886) new combination ( Figs 5 , 6 )

Synonymy: Akanthoporeus australis Sieg, 1986

Leptognathia australis Beddard, 1886

Leptognathia gracilis Shiino, 1970

Leptognathia gracilis Kudinova­Pasternak & Pasternak, 1981

Material examined: 29 individuals. ZMH K­40574 RV ”Walther Herwig” St. 96, three juvenile males, ZMH K­40575 RV ”Walther Herwig” St. 120, one female, ZMH K­40576 RV ”Walther Herwig” St. 138, one female, one juvenile male, ZMH K­40577 RV ”Walther Herwig” St. 149, one female, ZMH K­40578 RV ”Walther Herwig” St. 166, one female, one male, ZMH K­40579 RV ”Walther Herwig” St. 266, one female, ZMH K­40579 RV

”Polarstern” St. 6, one female, ZMH K­40580 RV ”Polarstern” St. 20, two females (one dissected) , nine neuters, ZMH K­40581 RV ”Polarstern” St. 147, one female , ZMH K­ 40582 RV ”Polarstern” St. 153, four females , ZMH K­40583 RV ”Polarstern” St. 155, two females .

Diagnosis: Cheliped carpal shield well developed, propodus with lateral crenulation, dactylus with dorsal crenulation.

Description: non­ovigerous female. Body ( Fig. 5a, b ): long, about eight times longer than wide. Body length 1.2 to 3.0 mm. Cephalothorax ( Fig. 5a, b ): about 1.5 times longer than wide, narrowing to antennule insertion. Pereon ( Fig. 5a, b ): pereonite 1 shortest, pereonites 5 and 6 of equal length, pereonite 2 longer than pereonite 5 and of equal length to pereonites 3 and 4. Pleon ( Fig. 5a, b ): pleonites of equal length and each with one simple short lateral seta; pleotelson rounded.

Antennule ( Fig. 5c ): article 1 longest, with one long and three short setae; article 2 as long as article 4, with one long simple seta; article 3 shortest, with two terminal simple setae; article 4 with six terminal setae.

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

Labrum ( Fig. 6d ): hood­shaped, with a row of setules on the distal margin.

Mandible ( Fig. 6c ): well calcified, pars molaris bent ventrally; lacinia mobilis broad with small denticles on distal edge.

Maxillula ( Fig. 6b ): with three pinnated, two short and three simple terminal spiniform setae.

Maxilla ( Fig. 6f ): triangular, naked.

Labium ( Fig. 6e ): composed of two triangular lobes, with one short simple seta at distal outer margin.

Maxilliped ( Fig. 6g ): endites not fused, with no special features.

Epignath ( Fig. 6a ): as long as Maxillula, with no special features.

Cheliped ( Fig. 5f ): basis as long as carpus; merus with one thin ventral simple seta; carpus with two ventral and two dorsal setae, one near the basis and one near insertion of propodus, carpal shield well­developed, smooth; propodus twice as long as dactylus, with a fine crenulation on the inferior outer margin and four teeth on cutting edge; dactylus with prominent crenulation on the dorsal margin.

Pereopod 1 ( Fig. 5g ): coxa naked; basis short about 2.5 times longer than wide, with one simple dorsal seta; ischium short with one simple seta; merus as long as carpus, with one spiniform seta; carpus with two spiniform setae; propodus with one terminal short spiniform seta; dactylus smooth; unguis as long as dactylus.

Pereopod 2 ( Fig. 5h ): as pereopod 1, except coxa with seta; basis with two simple dorsal setae; merus shorter than carpus; carpus with three spiniform setae.

Pereopod 3 ( Fig. 5i ): as pereopod 1, except coxa with seta; merus shorter than carpus; propodus with terminal spine.

Pereopod 4 ( Fig. 5j ): basis about 2.5 times longer than broad, with one setulose and one simple setae; ischium short with two simple setae; merus shorter than carpus, with two spiniform setae; carpus with three spiniform setae; propodus with terminal spine and four spiniform setae; unguis about two thirds of dactylus length.

Pereopod 5 ( Fig. 5k ): as pereopod 4, except basis with an extra simple seta; carpus and propodus with a row of spinules ventrally.

Pereopod 6 ( Fig. 5l ): as pereopod 4, except basis with only one ventral setulose and one dorsal simple setae.

Pleopods ( Fig. 5m ): basal article triangular, exopod with seven long simple setae; endopod with seven long simple setae.

Uropods ( Fig. 5e ): exopod half as long as article 1 of endopod. Exopod article 1 naked; article 2 with two terminal simple setae. Endopod article 1 with one terminal seta; article 2 with four simple terminal setae.

Juvenile males body length 1.4 to 2.0 mm.

Mancas up to 1.2 mm.

Distribution: this species is found in the Weddell Sea, around Elephant Island, South Orkney Islands, South Shetland Islands, Kerguelen Island, Antarctic Peninsula.

Remarks: this species resembles P. gracilis and P. antarctica very closely. The differences are at the cheliped level, the carpal shield in P. australis is bigger than in P. gracilis and P. antarctica . Paraleptognathia antarctica lacks the fine crenulation on the lateral external edge of the propodus.

Figures

FIGURE 5. Paraleptognathia australis ZMH K­40580 a. Body dorsal view, b. Body lateral view. Scale bar 1mm. c. Antennule, d. Antenna, e. Uropod, f. Cheliped, g. Pereopod 1, h. Pereopod 2, i. Pereopod 3, j. Pereopod 4, k. Pereopod 5, l. Pereopod 6, m. Pleopod. Scale bar 0.25 mm.

FIGURE 6. Paraleptognathia australis ZMH K­40580 a. Epignath, b. Maxillula, c. Mandibles, d. Labrum, e. Labium, f. Maxilla, g. Maxilliped. Scale bar 0.1 mm.