Typhlotanais mixtus Hansen, 1913

Błażewicz-Paszkowycz, Magdalena & Bamber, Roger N., 2011, Tanaidomorph Tanaidacea (Crustacea: Peracarida) from Mud-Volcano and Seep Sites on the Norwegian Margin, Zootaxa 3061, pp. 1-35 : 14-16

Typhlotanais mixtus Hansen, 1913

( Fig. 8 )

Peraeospinosus mixtus Sieg 1968 b, 156–162, figs 107–11.

Typhlotanais mixtus Błażewicz-Paszkowycz 2007 , 108–112, figs 2–64.

Material examined. 2ƤƤ (MNHN-IU-2010-2840), Vicking, PL277-7, ASPI 4, PP-V16 HMMV, 72°00.336ʹN 14°42.723ʹE, 1263 m, 06/06/2006; 1Ƥ (dissected, 3 slides) (MNHN-IU- 2010-2841), 1Ƥ, 1 juvenile (MNHN-IU- 2010-2842), Vicking, PL277-7, ASPI 6, PP-V14 HMMV, 72°00.335ʹN 14°42.746ʹE, 1263 m, 06/06/2006; 1Ƥ (MNHN-IU- 2010-2843) Vicking, PL277-7, ASPI 7, PP-V16 HMMV, 72°00.336ʹN 14°42.749ʹE, 1263 m, 06/06/ 2006.

This species was redescribed by Błażewicz-Paszkowycz (2007) from a syntype. The present material agrees well with that description, other than the uropod rami being a little more slender, and their articulation somewhat obscure (see below). We are able to add the morphology of the labrum, the maxilliped, and of the posterior pereopods to that description.

Supplementary description. Labrum ( Fig. 8 A) rounded, hood-shaped, with marginal microtrichia. Maxilliped ( Fig. 8 B) palp first article naked, second article with one fine outer distal and two simple and one distally-denticulate inner setae, third article with four inner setae, longest seta not reaching tip of fourth article, fourth article with five distal and one outer subdistal seta; basis with single seta not reaching margin of endites; endites distally with two setae and two oval tubercles, outer margin with microtrichia.

Pereopod 4 ( Fig. 8 C) coxa fused; basis stouter, three times as long as wide with one penicillate seta; ischium with two ventral setae; merus slightly longer than carpus, with two short ventrodistal spines; carpus with dorsodistal seta, inner and outer short finely-denticulate ventrodistal spines, and with ample ventral prickly-tubercles surrounded by microtrichia; propodus 1.6 times as long as carpus, with two short ventrodistal spines, one strong dorsodistal seta and dorsal penicillate seta, distal margin with microtrichia; dactylus with lateral microtrichia, longer than distinct unguis, together 1.2 times as long as propodus. Pereopod 5 (not figured) as pereopod 4. Pereopod 6 ( Fig. 8 D) as pereopod 4, but propodus with three stout dorsodistal setae, unguis proportionately shorter.

Uropod ( Fig. 8 E) biramous, basis naked; exopod of two segments showing poor articulation, with single distal seta on proximal segment, one longer and one shorter distal setae on second segment; endopod longer than exopod, of two segments showing poor articulation, two penicillate and one simple setae distally on proximal segment, one penicillate and five subequal simple setae distally on second segment.

Remarks. Previous records are listed in Błażewicz-Paszkowycz (2007), and include in the Norwegian Basin from 63°22’N to 69°25’N and from 6°58’W to 16°20’W, at a depth range of 906 to 1939 m, and the Davis Strait (61°50’N 56°21’W) at 2624 m ( Hansen 1913). The present records extend that distribution further north and east.

Figures

FIGURE 8. Typhlotanais mixtus Hansen, 1913, A, labrum; B, maxilliped; C, pereopod 4; D, pereopod 6; E, uropod. Scale lines = 0.1 mm.