Typhlamia mucronata ( Hansen, 1913 ) 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 : 87-90

Typhlamia mucronata ( Hansen, 1913) n. comb.

( Figs 48–49 )

Typhlotanais mucronatus: Hansen (1913) 3 (3): 37, 42–44; Stephensen, (1932) 6: 350; Kudinova-Pasternak (1970) 86: 348; Lang (1970) (2), 23 (4): 275, 289; Kudinova-Pasternak (1973) 91: 153; Kudinova-Pasternak (1985) 120: 63; Kudinova-Pasternak (1990) 126: 94; Holdich & Bird (1985): 443; Larsen (2005): 210.

Material examined: Syntype: female, CRU 3916 , Ingolf -Station , St. 120, North-East of Iceland, 67°29'N, 11°32'W, depth 885 fm (1618 m); syntype: female, CRU 7423 , Ingolf-Station, Sta 119, North-East of Iceland, 67°53'N, 10°19'W, depth 1010 fm (1947 m); syntype: female dissected on slides, CRU 3885 , the same locality .

Diagnosis: Carapace a little longer than wide; pereopod-1 carpus with seta as long as propodus length. Pereopod-2 merus and carpus with short setae (not longer than half of following article respectively). Uropod exopod little longer than endopod proximal article.

Description: Nonovigerous female. Body length 2.1 mm ( Figs 48A,B ), 7.8 times as long as broad. Carapace smooth, rounded laterally, as long as wide, 13 % of total body length; rostrum blunt. Pereonites smooth, slightly rounded lateral margins; pereonites 1, 2 and 6 subequal, 1.7 times as wide as long, pereonite-1 0.7 times as long as carapace; pereonite-3 almost as long as pereonite-4; pereonite-5 a little shorter than pereonite-4, as long as wide. Pleon 20% of body length, as long as pereonites 5, 6 plus 0.3 of pereonite-4 combined; pleonites 1–5 similar in size; pleotelson semi-circular; caudal projection reduced.

Antennule ( Fig. 48D ): Twice as long as carapace; article-1 with fusion line, seven times as long as wide, with a few setae on outer and inner margin, two submedial setae reaching over end of article; article-2 with two simple setae distally; article-3 nine times as long as wide, tipped by six long simple setae.

Antenna ( Fig. 48E ): Article-2 more than half as long as article-3; article-3 with one small seta; article-4 twice as long as article-5, with six simple setae distally; article-5 with one distal seta; article-6 tipped by four setae.

Mouth parts: Labrum lost during dissection. Mandible ( Figs 48F,G ) stout; molar process well-developed, with crenulated distal margin; lacinia mobilis well-developed, crenulated. Maxillule ( Fig. 48H ) endite with nine spiniform setae distally; palp lost during dissection. Maxilla lost during dissection. Maxilliped ( Fig. 49A ): bases fused little longer than wide; each with simple setae reaching far over endites; endite with two tubercles on distal margin; palp four-articled: article-1 naked; article-2 wedge-shaped, with three setae on inner margin; article-3 trapezoidal, with three bipinnate and one simple setae on inner margin, article-4 slen- der (2.5 times as long as wide), with one simple seta on outer margin and five bipinnate terminal setae. Epignath ( Fig. 48I ) tip not rounded. Labium ( Fig. 48J ) bi-lobed, outer corner of inner lobe and outer lobe with minute setae.

Cheliped ( Fig. 49B ): Basis 1.7 times as long as wide, with one seta on dorsal margin; merus wedgeshaped, with one short seta ventrally; carpus about 2.7 times as long as broad, with two dorsal setae and with two long setae ventrally; propodus and fixed finger just as long as carpus, about four times as long as wide; fixed finger with three setae on inner margin and two setae on ventral margin.

Pereopod-1 ( Fig. 49C ): Coxa with seta; basis little shorter than merus, carpus and propodus combined; ischium with simple seta; merus little shorter than carpus, with simple seta distally; carpus with four short and one long (longer than half of propodus) setae distally; propodus 1.4 times as long as carpus, with one ventral and two dorsal setae; dactylus almost as long as unguis, together as long as half of propodus.

Pereopod-2 ( Fig. 49D ): Coxa with seta; basis a little longer than merus and carpus combined; ischium with simple seta; merus a little shorter than carpus, with one simple seta and one thick seta distally; carpus with four short and one spiniform setae distally; propodus a little longer than carpus, with one spiniform seta ventrally and two simple setae on dorsal margin; dactylus almost as long as unguis.

Pereopod-3 ( Fig. 49E ): Similar to pereopod-2.

Pereopod-4 ( Fig. 49F ): Clinging type; basis with one seta ventrally; ischium with one seta ventrally; merus with two spiniform setae; carpus with spiniform seta distally and small prickly tubercles; propodus over three times as long as wide, with two spiniform ventro-distal setae and with distal setae just reaching end of dactylus; unguis with bifid tip.

Pereopod-5 ( Fig. 49G ): Similar to pereopod-4.

Pereopod-6 ( Fig. 49H ): Similar to pereopod-4, but propodus with three distal setae as long as dactylus.

Pleopods 1–5 ( Fig. 49I ): Basal article naked; exopod with nine plumose setae on outer margin and one seta on inner margin; endopod with 17 pinnate setae on outer margin. Gap between most proximal setae and the other setae in both rami.

Uropod ( Fig. 49J ): Endopod two-articled; proximal article almost as long as distal article, with one distal seta; distal article tipped by five simple setae; exopod one-articled, little longer than endopod proximal article, tipped by strong long and short simple setae.

Distribution: From published sources, the species has been found at a few places in the North Atlantic: North-East off Iceland (type locality), South of Jan Mayen, and the Bay of Biscay at depths of 1618–1847 m; and it was also recorded in the North Pacific (45°32'N, 153°46'E, depth 6675–6710 m; 44°17'N 149°37'E, depth 4840 m; 56°14'N, 139°44'W, depth 3450 m) by Kudinova-Pasternak (1970; 1973).

Remarks: The wide distribution of Typhlamia (= Typhlotanais ) mucronata ( Hansen, 1913) in both the North Atlantic and Pacific is questionable, but because material studied by Kudinova-Pasternak is not available for study the problem cannot be solved at the moment.

T. mucronata can be distinguished from the two other species ( T. sandersi and T. bella n. sp.) by its having relatively short setae on the carpus of the second pereopod while in the two other species there are two long setae reaching the end of the propodus.

Figures

FIGURE 48. Typhlamia mucronata. A) Holotype, female, dorsal view; B) Holotype, female, lateral view; C) Carapace, ventral view; D) Antennule; E) Antenna; F) Left mandible; G) Right mandible; H) Maxillule endite distally I) Epignath; J) Labium. Scale A, B = 1 mm; C–E, J= 0.1 mm; F–I = 0.01 mm.

FIGURE 49. Typhlamia mucronata. A) Maxilliped; B) Cheliped; C) Pereopod-1; D) Pereopod-2; E) Pereopod-3; F) Pereopod-4; G) Pereopod-5; H) Pereopod-6 distal part; I) Pleopod; J) Uropod. Scale 0.1 mm.