Torquella galatheae, 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 : 83-86

Torquella galatheae n. sp.

( Figs 46–47 )

Material examined: Holotype: female, ( CRU ###), partially dissected on slides, Galathea Station 716, 9°23'N, 89°32'W, depth 3570 m, herring otter trawl, bottom dark, muddy clay, bottom temp.: c. 1.9°C, 6 May 1952.

Diagnosis: Carapace 1.2 times as long as wide. Pereonite-2 1.5 times as long as pereonite-1; pereonites 3 and 5 1.4 times as long as wide. Chela three times as long as wide. Antennule article-3 less than three times as long as article-2. Pereopod-1 merus and carpus shorter than basis, merus with two short setae; pereopod-2 propodus with two long setae dorsally, merus with one spiniform and one simple seta, carpus with three spiniform and two short simple setae; pereopods 4–5 propodus distal seta reaches end of unguis; pereopods 4–6 with numerous spines around prickly tubercles; pereopod-6 propodus with distal setae subequal; uropod rami two-articled, exopod 0.8 times length of endopod.

Etymology: The name is given after the research vessel r/v Galathea from which the species was collected.

Description: Female. Body length 3.7 mm ( Fig. 46A ), almost ten times as long as wide; carapace smooth, 15% of body length, 1.3 times as long as wide, slightly narrowing rostrally, rounded laterally, rostrum acute. Pereonite-1 twice as wide as long, antero-lateral corners expanded forward; pereonite-2 little wider than long, 1.5 times as long as pereonite-1; pereonites 3–5 subequal, 1.4 times as long as wide; pereonite-6 1.5 as wide as long. Pleon 15% of body length, pleonites 1–5 similar in size; pleotelson semi-rectangular.

Antennule ( Fig. 46B ): Article-1 over three times as long as wide, with three groups of pinnate and simple setae; article-2 with two simple and one pinnate setae distally; article-3 over twice as long as article-2, with five simple and one pinnate setae distally.

Antenna ( Fig. 46C ): Article-2 little longer than article-3; article-3 with one seta; article-4 is 2.2 times as long as article-5, with two simple and two pinnate setae distally; article-5 with one simple seta distally; article-6 very short, with five terminal setae.

Mouth parts: Labrum ( Fig. 46D ) hood-shaped with numerous small setae. Mandible ( Fig. 46E,F ) stout; incisor with row of teeth on upper margin; molar process well-developed, edges supported with teeth-like structures, lower edge with spines; lacinia mobilis well-developed, crenulated. Maxillule ( Fig. 46G ) endite with eight apical spiniform setae. Maxilla ( Fig. 46H ) oval, naked. Maxilliped ( Fig. 46J ) bases fused, bilobed, with simple setae reaching over half length of endites; endite with two setae and two tubercles on distal margin; palp four-articled: article-1 naked; article-2 wedge-shaped, with three setae on inner margin and one short seta on outer margin; article-3 with three serrated setae and one simple setae on inner margin; article-4 with one serrated seta on outer margin and five terminal setae. Labium ( Fig. 46I ) bilobed; outer corner of inner lobe and outer lobe with minute setae.

Cheliped ( Fig. 47A ): Basis twice as long as wide; merus wedge-shaped with one seta ventrally; carpus about 2.8 times as long as broad, with one dorsal seta and with two long setae ventrally; propodus and fixed finger as long as carpus, about three times as long as wide, with one long setae near insertion of dactylus; fixed finger with three setae on inner margin and with two simple setae on ventral margin.

Pereopod-1 ( Fig. 47B ): Of walking type; coxa present; basis a little longer than merus and carpus combined, with three setae on dorsal margin; ischium with one seta; merus as long as carpus, with one spiniform and one simple seta distally; carpus with one spiniform, two simple, one pinnate setae distally and one small spiniform setae subventrally; propodus 1.3 times as long as carpus with one seta ventrally and three setae dorsally; dactylus and unguis combined 0.75 times length of propodus.

Pereopod-2 ( Fig. 47C ): Of walking type; coxa present; basis with three setae dorsally, shorter than ischium, merus and carpus combined; merus a little shorter than carpus, with one simple and one spiniform setae distally; carpus with three spiniform setae and two simple setae distally; propodus a little longer than merus and carpus combined, with spiniform seta ventrally and two long setae (reaching end of unguis) dorsally; dactylus shorter than half of unguis.

Pereopod-3 ( Fig. 47D ): Similar to pereopod-2, but carpus with four spiniform setae.

Pereopod-4 ( Fig. 47E ): Clinging type; coxa absent; basis with one simple seta dorsally and one pinnate seta ventrally; ischium with two setae ventrally; merus with two spiniform setae and microtrichiae on ventral margin; carpus with two spiniform setae and prickly tubercles surrounded by dense spines; propodus five times as long as wide, with two spiniform ventro-distal setae and with distal setae reaching the end of unguis; dactylus and unguis combined as long as two-thirds of propodus; unguis distally simple with row spines on ventral margin.

Pereopod-5 ( Fig. 47F ): Similar to pereopod-4.

Pereopod-6 ( Fig. 47G ): Similar to pereopod-4, but propodus with three subequal setae distally.

Pleopods 1-5 ( Fig. 47H ): Endopod with 25 plumose setae on outer margin; exopod with 16 setae on outer margin and one seta on inner margin.

Uropod ( Fig. 47I ): Endopod two-articled; proximal and distal article subequal; proximal with one seta distally, distal article with five simple and two pinnate terminal setae. Exopod with two articles; distal article 1.7 times as long as proximal article, tipped by long and short simple seta.

Distribution. Species known only from the type locality: Acapulco-Panama: 9°23'N, 89°32'W, at a depth of 3570 m.

Remarks: From most of its congeners T. galatheae n. sp. can be distinguished by having pereonites 3–5 longer than wide. This character is shared with T. elegans , but T. elegans lacks the spiniform setae on the merus of pereopods 2 and 3 that are present in T. galatheae .

Figures

FIGURE 46. Torquella galatheae n. sp., female paratype. A) Holotype, female, dorsal view; B) Antennule; C) Antenna; D) Labrum; E) Left mandible; F) Right mandible; G) Maxillule; H) Maxilla; I) Labium; J) Maxilliped. Scale A = 1 mm; B, C, I = 0.1 mm, D-J = 0.01mm.

FIGURE 47. Torquella galatheae 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; I) Uropod. Scale = 0.1 mm.