Typhlotanais squamiger, Błażewicz-Paszkowycz, 2007

Błażewicz-Paszkowycz, Magdalena, 2007, Figure 6. Typhlotanais Compactus, Female A In Family Nototanaidae Sieg, 1976 And Typhlotanaidae Sieg, 1984, Zootaxa 1598, pp. 1-141 : 121-124

Typhlotanais squamiger n. sp.

( Figs 71–73 )

Material examined: Holotype: non-ovigerous female ( K 41418 ), ANT XXII/3 , PS 67/88-8 E, 68°3.66'– 68° 3.61'S, 20°27.90'– 20°27.52' W, depth 4929–4931 m, epibenthic sledge, 27 Feb 2005.

Paratype: non-ovigerous females (dissected on slides), ( K 41437 ) the same locality .

Diagnosis: Strong spiniform setae on pereopods 2 and 3 merus, carpus and propodus and pereopods 4–6 propodus; pereopods 2 and 3 propodus with one regular and one strong setae dorso-distal; antennule, cheliped and pereopods 1–3 with scales, cheliped merus strongly calcified.

Etymology: squamiger (Lat.) – bearing a scale. The name reflects the presence of scale-like structures on the chelipeds and pereopods.

Description: Non-ovigerous female. Body length 2.8 mm ( Fig. 71A,B ), long, 8.3 times as long as wide; carapace smooth, margins parallel tapering proximally, 1.3 times as long as wide; rostrum weakly pointed; pereonites smooth, rectangular, with parallel lateral margins; pereonite-1 shortest, less than twice as wide as long; pereonites 2 and 6 0.8 times as long as wide; pereonite-3 square; pereonites 4 and 5 subequal, slightly shorter than wide. Pleon as long as carapace and pereonite-1 combined; pleonites 1–5 similar in size; pleotelson rounded; caudal projection with two strong spines.

Antennule ( Fig. 72A ): Article-1 about three times as long as wide, and twice as long as article-3, with two small simple setae and two pinnate spines distally, numerous scale-like structures along article; article-2 as long as wide, with two small setae distally; article-3 over three times as long as article-2.

Antenna ( Fig. 72B ): Article-1 broken; article-2 twice as long as article-3, with one simple seta; article-3 with numerous minute scales distally; article-4 twice as long as article-5, with one long, one short and one pinnate setae distally; article-5 with simple seta; article-6 with four simple subterminal and terminal setae.

Mouth parts: Labrum ( Fig. 72C ) hood-shaped, covered by numerous, relatively long setae. Mandible ( Figs 72D,E ) stout; molar process well-developed, with strongly crenulated edges; lacinia mobilis well-developed, crenulated. Maxillule ( Fig. 72F ) endite with eight terminal setae, additional (ninth) seta visible centrally, three short simple setae on outer margin; palp lost during dissection. Maxilla ( Fig. 72G ) oval. Maxilliped ( Fig. 72I ) bases nearly twice as long as wide, without simple setae distally; each endite with two setae and two large tubercles on distal margin; palp article-1 with microtrichiae; article-2 wedge-shaped, with two simple and one serrated setae on inner margin and one short simple seta on outer margin; article-3 trapezoidal, with four setae on inner margin and scale structures on outer margin; article-4 with one simple seta on outer margin and five strong terminal setae. Labium ( Fig. 72H ) with bunch of setae on outer corner of inner lobe; outer lobe with small setae.

Cheliped ( Fig. 73A ): Basis twice as long as wide, naked; merus with simple seta ventrally; carpus twice as long as wide, covered by numerous scales, with two long and one short setae ventrally and two short setae dorsally, carpal shield moderately developed; chela almost as long as carpus, twice as long as wide; fixed finger with three setae on inner margin and with two simple setae ventrally; dactylus slightly curved, with one short seta proximally.

Pereopod-1 ( Fig. 73B ): Of walking type; coxa naked, with small spur; basis just as long as merus and carpus combined, with two setae dorsally and three setae ventrally; ischium short with one simple seta; merus almost as long as carpus but shorter than propodus, with two short setae distally; carpus with three short setae and one spiniform seta distally; propodus with two serrated subdistal setae dorsally; unguis twice as long as dactylus; unguis and dactylus slightly shorter than propodus.

Pereopod-2 ( Fig. 73C ): Of walking type; basis as long as merus, carpus and half of propodus combined, with two simple setae ventrally; ischium with one seta; merus as long as carpus, with two simple and one spiniform setae distally; carpus with few scales ventrally and with three short setae and one spiniform seta distally; propodus with few scales ventrally, strong spiniform setae ventrally and with one thick and one thin seta dorsally; dactylus shorter than unguis, combined little shorter than propodus.

Pereopod-3 ( Fig. 73D ): Similar to pereopod-2, but basis as long as rest of articles combined.

Pereopod-4 ( Fig. 73E ): Of clinging type; basis naked; ischium with two setae; merus almost as long as carpus, with two subdistal, spiniform setae; carpus with hooks distally, two sensory setae dorsally, and large (over half as long as article) prickly tubercle ventrally; propodus a little longer than carpus, with two strong spiniform setae ventrally, and one distal seta reaching half of dactylus; dactylus tipped by simple unguis; dactylus and unguis as long as propodus.

Pereopod-5 ( Fig. 73F ): Similar to pereopod-4, but propodus with medial, pinnate seta on propodus dorsal margin.

Pereopod-6 ( Fig. 73G ): Similar to pereopod-5, but propodus with three terminal setae reaching half of unguis.

Pleopods 1-5 ( Fig. 73H ): All pleopods similar; exopod outer margin with twelve plumose setae, andwith one plumose seta one inner margin; endopod arranged with sixteen plumose setae on outer margin; both rami with clear gap between proximal outer seta and others.

Uropod ( Fig. 73I ): Basal article shorter than endopod proximal article; exopod and endopod two-articled; exopod about 0.4 times length of endopod; proximal article 0.6 times as long as distal article; distal article tipped by two simple setae; endopod proximal article 1.5 times as long as distal article, with six spiniform setae on inner margin; distal article with one seta at middle and four terminal setae.

Distribution: Antarctic, Weddell Sea.

Figures

FIGURE 71. Typhlotanais squamiger n. sp. A) Holotype, female, dorsal view; B) Holotype, female, lateral view. Scale = 1 mm.

FIGURE 72. Typhlotanais squamiger n. sp., female paratype. A) Antennule; B) Antenna; C) Labrum; D) Left mandible; E) Right mandible; E’) Molar process; F) Maxillule; G) Maxilla; H) Labium; I) Maxilliped. Scale: A, B = 0.1 mm; C–I = 0.01 mm.

FIGURE 73. Typhlotanais squamiger n. sp., female paratype. A) Cheliped; B) Pereopod-1; C) Pereopod-2; D) Pereopod-3; E) Pereopod-4; F) Pereopod-5; G) Pereopod-6; H) Pleopod; Uropod. Scale = 0.1 mm.