Typhlotanais andeepae, 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 : 126-131

Typhlotanais andeepae n. sp.

( Figs 74–76 )

Material examined: Holotype: non-ovigerous female, ( K 41336 ), ANT XXII/3 , EBS 133-2-S, 62°46.49'– 62°46.38'S, 53°03.50'– 53°03.98'W, depth 1594– 1579 m, epibenthic sledge, 15 Mar 2005 ; Paratypes: eight non-ovigerous females (one dissected on slides), the same locality; one non-ovigerous female, ( K 41339 ), ANT XXII/3 , PS 67/81-9, 70°32.94'– 70° 33.15'S, 14°34.40'– 14° 32,74’W, depth 4390–4392 m, Agassiz trawl, 24 Feb 2005; two females , body length 1.8 mm and 1.1 mm, ( K 41341 ), ANT XXII/3 , PS 67/74-6, 71°18.35'– 71°18.28'S, 13°57.71'– 13°57.31'W, depth 1030–1040 m, epibenthic sledge, 20 Feb 2005 ; one nonovigerous female, ( K 41340 ), ANT XXII/3 , PS 151-7-E, 61°45.46'– 61°45.34'S, 47°07.57'– 47°07.78’W, depth 1181–1188 m, epibenthic sledge, 20 Mar 2005; one female, ( K 41338 ) , ANT XXII/3 , PS 80-9, 70°39.07'– 70°39.22'S, 14°43.36'– 14°43.39'W, depth 3103– 3102 m, epibenthic sledge, 23 Feb 2005; two females, ( K 41337 ) , ANT XXII/3 PS 88-8-E, 68°03.66'- 68°03.61'S, 20°27.90'– 20°27.52'W, depth 4929–4931 m, epibenthic sledge, 27 Feb 2005 .

Etymology: The species is named to acknowledge the ANDEEP Expedition during which the species was collected.

Diagnosis: Body 5.3 times as long as wide. Carapace slightly tapering proximally, rounded laterally. All pereonites wider than long, clearly rounded laterally (width: length ratio 3.3, 2.3, 2.0, 1.4, 1.6, and 1.6 respectively). Pleotelson gently rounded. Antennule as long as carapace; article-1 with about five simple setae along margin; antenna article-2 and 3 without spines; cheliped compact; basis reaches the anterior edge of pereonite- 1, carpus with moderately developed carpal shield, twice as long as wide, slightly longer than chela. Pereopods 1–3 coxa without acute projection, merus without spiniform seta; pereopod-1 propodus with long subdistal seta on ventral margin (over ten times as long as wide); pereopods 2–3 carpus with spiniform seta, merus and carpus with long setae (reaching half of following article); pereopods 4–6 carpus with large round prickly tubercles (at least as long as half of article), unguis tip bifid, propodus distal setae reaching over unguis. Both pleopod rami with proximal seta separated from others by gap. Uropods rami two-articled; endopod proximal article twice as long as distal.

Description: Non-ovigerous female. Body length 2.1 mm ( Figs 74A, B ), short, 5.3 times as long as wide; carapace smooth, rounded laterally, 1.2 times as long as wide; rostrum weakly pointed; pereonites smooth, wider than long, with rounded lateral margins; pereonite-1 short, 3.3 times as wide as long; pereonite-2 and 3 slightly longer; pereonites 4–6 the longest, 1.5 as wide as long. Pleonites 1–5 similar in size; pleon as long as pereonites 4 and 5 together; pleotelson rounded; caudal projection poorly developed.

Antennule ( Fig. 75A ): Article-1 more than twice as long as wide; 1.5 times as long as articles 2 and 3 combined, with five simple setae and five pinnate setae along article and distally; article-2 half as long as article-3, with two simple setae distally; article-3 with six simple terminal setae.

Antenna ( Fig. 75B ): Article-1 lost during dissection; article-2 twice as long as article-3, with one simple seta; article-3 with one simple seta; article-4 is 1.5 times as long as article-5, with three simple and four pinnate setae distally; article-5 with simple seta; article-6 with five simple subterminal and terminal setae.

Mouth parts: Labrum ( Fig. 75C ) hood-shaped, covered by numerous minute setae. Mandible ( Figs 75D, E ) stout; molar process well-developed, with strongly crenulated edges; lacinia mobilis well-developed, crenulated. Maxillule ( Fig. 75F ) endite with seven terminal setae (two bifurcated); palp lost during dissection. Maxilla lost during dissection. Maxilliped ( Fig. 75H ) bases little longer than wide; each with simple setae reaching over endite; each endite armed with two plumose setae and two tubercles on distal margin; palp article-1 naked; article-2 wedge-shaped, with three setae on inner margin and one short, simple seta on outer margin; article-3 trapezoidal, with four setae on inner margin; article-4 with one simple seta on outer margin and five terminal setae. Labium (Fig, 75 G) with group of setae on outer corner of inner lobe; outer lobe with small setae.

Cheliped ( Fig. 75I ): Basis 1.5 times as long as wide, with one simple seta on outer margin, posterior margin rounded; merus wedge-shaped, with seta on ventral margin; carpus twice as long as wide (length:width ratio 2.0), with two simple setae and one minute seta 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 two spiniform setae on inner margin and with one short seta proximally.

Pereopod-1 ( Fig. 76A ): Of walking type; coxa with one simple setae; basis as long as merus, carpus and propodus combined, with three proximal setae dorsally; ischium short with one simple seta; merus almost as long as carpus but shorter than propodus, with one short and one long setae distally; carpus with two long and one short setae distally; propodus with three subdistal setae dorsally and one long subdistal simple setae ventrally; unguis twice as long as dactylus; unguis and dactylus little shorter than propodus.

Pereopod-2 ( Fig. 76B ): Of walking type; basis slightly shorter than rest of articles combined, with three proximal setae dorsally; ischium with one seta; merus almost as long as carpus with three long setae distally (reaching half of carpus); carpus with two long, one short and small spiniform seta distally; propodus with two subdistal setae dorsally and one spiniform seta ventrally; dactylus shorter than unguis.

Pereopod-3 ( Fig. 76C ): Walking type; basis a little shorter than rest of articles combined, with three proximal setae dorsally; ischium with one seta; merus with one long seta distally; carpus with two long and two short setae and one spiniform seta distally and with a few combs of spines ventrally; propodus with one subdistal setae reaching over end of dactylus and one spiniform seta on ventrally; dactylus shorter than unguis.

Pereopod-4 ( Fig. 76D ): Of clinging type; basis wide, with three simple setae; ischium with two setae; merus almost as long as carpus, with two subdistal spines and numerous microtrichae on ventral margin; carpus with hooks distally, one sensory seta dorsally and rounded, large (at least half as long as article) prickly tubercles ventrally; propodus 1.7 times as long as carpus, with one pinnate seta dorsally, two spiniform setae ventrally and one serrated distal seta reaching over unguis; dactylus and unguis half as long as propodus, unguis with bifid tip.

Pereopod-5 ( Fig. 76E ): Similar to pereopod-4.

Pereopod-6 ( Fig. 76F ): Similar to pereopod-5, but propodus with three distal setae.

Pleopods 1–5 ( Fig. 76G ): All pleopods similar; exopod outer margin with ten plumose setae, inner margin with one plumose seta; endopod with thirteen plumose setae on outer margin; both exopod and endopod with small gap between most proximal seta and remind setae.

Uropod ( Fig. 76H ): Basal article shorter than endopod proximal article; exopod and endopod two-articled; exopod little shorter than endopod; exopod proximal article almost half as long as distal article, with one sim-

ple seta distally; article-2 tipped by two setae (short and long); endopod proximal article twice as long as distal one, with two simple setae distally; distal article with five terminal simple setae.

Distribution: Antarctic: Eastern Weddell Sea, east of Elephant Island and the Orkney Islands at depths of 1030 to 4931 m.

Remarks: Typhlotanais andeepae n. sp. has two bifurcated terminal spiniform setae on the maxillule. This character has been observed before in a few abyssal tanaidacean species such as Collettea minima Hansen, 1913 , Arthrura andriashevi Kudinova-Pasternak, 1966 , Curtichelia expressa Kudinova-Pasternak, 1987 , Parafilitanais mexicana Larsen, 2002 , Cetiopyge mira Larsen & Heard, 2002 , Isopodidus janum, Larsen & Heard, 2002 , and Collettea lilliputa, Błażewicz-Paszkowycz & Larsen 2005 , representing various Paratanoidea families and emphasizing the polyphyletic character of this feature (Larsen, 2002).

Typhlotanais andeepae is most similar to T. cornutus from the North Atlantic, sharing a cluster of characters listed in the diagnosis of the group. The new species can be distinguished from T. cornutus by having a carapace longer than wide (length:width ratio 1.2) and pereonite-4 only 1.5 times as wide as long. The carapace of T. cornutus is clearly shorter than wide (width: length ratio 0.83) while pereonite-4 is over twice as wide as long.

A third species which shares the characters listed above (with exception of one-articled uropod rami) with T. cornutus and T. andeepae is Typhlotanais (= Peraeospinosus ) adipatus sensu Tzareva , from shallows off the Adelie Islands. Because the type material of T. adipatus sensu Tzareva is no longer available any conclusions about its similarity to T. cornutus and T. andeepae can only be based on Tzareva’s drawings— Fig. 9 , page 53.

However, it is almost certain that Typhlotanais adipatus sensu Tzareva and sensu Sieg, 1982 represent two different taxa. Tzareva’s species is compact (about five times as long as wide), in contrast to Sieg’s species that is almost seven times as long as wide, has short distal setae on propodus of pereopods 4–5, and dense minute setation in antenna articles 2–4 that is lacking in T. cornutus and T. andeepae .

Figures

FIGURE 9. Paratyphlotanais alveolus n. sp., female paratype. A) Antennule; B) Antenna; C) Labrum; D) Left mandible; E) Right mandible; F) Maxillule; F’) Palp; G) Maxilla; H) Labium; I) Maxilliped. Scale = A, B, I = 0.1 mm; C-H = 0.01 mm.

FIGURE 74. Typhlotanais andeepae n. sp., holotype, female. A) lateral view; B) dorsal view. Scale = 0.1 mm

FIGURE 75. Typhlotanais andeepae n. sp., female paratype. A) Antennule; B) Antenna; C) Labrum; D) Left mandible; E) Right mandible; F) Maxillule; G) Labium; H) Maxilliped; I) Cheliped. Scale: A, B, I = 0.1 mm; C–H = 0.01 mm.

FIGURE 76. Typhlotanais andeepae n. sp., female paratype. A) Pereopod-1; B) Pereopod-2; C) Pereopod-3; D) Pereopod-4; E) Pereopod-5; F) Pereopod-6; G) Pleopod; H) Uropod. Scale = 0.1 mm.