Typhlotanais sp. A

Błażewicz-Paszkowycz, Magdalena, 2007, Figure 6. Typhlotanais Compactus, Female A In Family Nototanaidae Sieg, 1976 And Typhlotanaidae Sieg, 1984, Zootaxa 1598, pp. 1-141 : 132-135

Typhlotanais sp. A

( Fig. 78 )

Material examined: one non-ovigerous female, body length 1.5 mm ANT XXII/3 , PS 81-9, 70°32.94'– 70°33.15'S, 14°34.40’– 14°32,74'W, depth 4390–4392 m, Agassiz trawl, 24 Feb 2005 .

Diagnosis: Body compact, short, 4.5 times as long as wide; carapace 1.3 times as wide as long; cheliped basis reaches pereonite-1 ventrally; pereonite-1 short (almost four times as wide as long), slightly wider than carapace in dorsal view; pleon 25% of total body length; antennule twice as long as carapace.

Description: Non-ovigerous female ( Fig. 78 ) body length up to 1.5 mm, 4.5 times as long as wide. Carapace smooth, rounded laterally, 15% of overall length, 1.3 times as wide as long; rostrum pointed; pereonites smooth rounded laterally; cheliped basis reaches pereonite-1 ventrally; pereonite-1 four times as wide as long, little wider than carapace; pereonite-2 longer than pereonite-1, about three times as wide as long; pereonite-3 longer than pereonite-2, about twice as wide as long; pereonite-4 twice as wide as long but slightly narrower than pereonite-3; pereonite-5 a little longer than pereonite-4, 1.7 times as wide as long; pereonite-6 three times as wide as long. Pleon 26% of body length, somewhat wider than pereonites 4–6, pleonites 1–5 similar in size.

Distribution: Eastern Weddell Sea, at depths of 4390–4392 m.

Remarks: This species was represented by only one specimen and it is not formally described here owing to the lack of material. The similar Typhlotanais penicillatus described by Sars (1882) from shallow waters of North Atlantic differs from Typhlotanais sp. A in having a carapace about as long as wide and a shorter antennule, 1.3 times as long as the carapace. A similar compact body and long antennule are observed in T. eximius ( Fig. 79 ), from the abyssal of the South-West Iceland, North Atlantic, but that species has long cheliped which is almost four times as long as wide, while it is only 2.5 times as long as wide in both Typhlotanais sp. A and T. penicillatus .

A short body habitus is also characteristic for T. solidus ( Fig. 80 ), although its relatively short antennule (little longer than carapace) suggests it may constitute a valid morpho-group. Because the species is known from the holotype specimen only that is covered by crystals, it is difficult to indicate its similarity to the others short-body morpho-groups at the moment.

Figures

FIGURE 78. Typhlotanais sp. A. female, A) dorsal view; B) lateral view; C) carapace ventral side. Scale = 0.1 mm.

FIGURE 79. Typhlotanais eximius Hansen, 1913, holotype, female. A) lateral view; B) dorsal view. Scale = 0.1 mm.

FIGURE 80. Typhlotanais solidus Hansen, 1913, female holotype. Scale = 0.1 mm.