Typhlotanais messinensis G.O. Sars 1882

Błażewicz-Paszkowycz, Magdalena, 2007, Figure 6. Typhlotanais Compactus, Female A In Family Nototanaidae Sieg, 1976 And Typhlotanaidae Sieg, 1984, Zootaxa 1598, pp. 1-141 : 103-107

Typhlotanais messinensis G.O. Sars 1882

( Figs. 58–60 )

Typhlotanais messinensis: G.O. Sars (1882a) 7: 39–40; Carus (1885) 1(2): 431; Norman & Stebbing (1886) 12: 109; G.O. Sars (1886) 11: 346–349; G.O. Sars, (1896): 18; Dollfus (1898) 11: 36; Norman (1899) 3: 340; Nierstrasz (1913) 32 (a): 34; Lang (1970) 23 (4): 274–275, 288; Larsen (2005): 209.

Material examined: CRU 3896, Messina 1-20/5.

Diagnosis: Antennule shorter than carapace; article-2 0.3 times as long as article-3. Antenna article-4 four times as long as wide. Cheliped carpus 2.5 times as long as wide wide. Pereopod-2-3 merus with short setae (shorter than half of carpus); propodus with spiniform seta ventrally; uropod rami two-articled.

Complementary description: Female 4.6 mm ( Fig. 58A,B ), body long, 7.1 times as long as wide; carapace smooth, 1.3 times as long as wide, lateral margins slightly rounded; rostrum slightly pointed; pereonites smooth, all wider than long; pereonite-1 shortest, almost twice as wide as long, half as long as pereonite-3; pereonites 2, 4 and 5 subequal, 1.5 times as long as pereonite-1; pereonite-3 longest; pereonite-6 0.6 times as long as pereonite-5. Pleon 1.5 times as long as carapace, pleonites 1–5 similar in size; pleotelson rounded.

Antennule ( Fig. 59A): Article-1 slender, three times as long as wide, with four short setae along article on inner margin and one simple and three pinnate setae distally; article-2 with simple seta distally; article-3 almost four times as long as article-2, with apical spur and four distal setae.

Antenna ( Fig. 59B): Article-2 a little longer than wide, with two setae distally, almost twice as long as article-3; article-4 five times as long as wide, with two setae distally; article-5 with one long seta distally; article-6 very short, with five terminal setae.

Mouth parts: Labrum ( Fig. 59C) hood-shaped, covered by minute setae. Mandible ( Figs 59D,E) molar well-developed, longer than incisor with irregular edges; incisor blunt; lacinia mobilis well-developed, crenulated. Maxillule ( Fig. 59F) endite with eight apical spiniform setae, palp lost during dissection. Labium ( Fig. 59G) withboth lobes poorly separated and sparsely setose distally. Epignath ( Fig. 59I) curved, simple distally. Maxilliped ( Fig. 59H): coxa reduced; basis fused in heart-shaped plate, 1.5 times as long as wide, with long seta; endite with two tubercles distally; palp article-1 unarmed; article-2 wedge-shaped, with three setae on inner margin and one minute seta on outer margin; article-3 trapezoidal, with four setae on inner margin; article-4 slender, with one simple seta on outer margin and five distal setae.

Cheliped ( Fig. 60A ): Basis slightly rounded, 1.8 times as long as wide; merus wedge-shaped, with one seta ventrally; carpus 2.5 times as long as wide, with two setae ventrally and with six minute setae along dorsal margin; propodus slightly shorter than carpus, with distal seta on inner side; fixed finger (propodus projection) tipped by strong spine, with three setae on well-calcified inner margin and two setae ventrally.

Pereopod-1 ( Fig. 60B ): Coxa with spur; ischium short, with one seta; merus almost as long as carpus; carpus with three simple setae distally; propodus 1.3 times as long as carpus, with three setae subdistally; dactylus half as long as unguis with one seta; dactylus and unguis combined 0.7 times as long as propodus.

Pereopod-2 ( Fig. 60C ): Coxa with spur; basis with three setae along article; ischium with simple seta; merus slightly shorter than carpus, with two simple setae and one spiniform seta distally; carpus a little longer than merus, with three simple setae and one spiniform distally; propodus almost as long as merus and carpus combined, with one spiniform seta ventrally and two setae dorsally; dactylus almost as long as unguis.

Pereopod-3 ( Fig. 60D ): Similar to pereopod-2.

Pereopod-4 ( Fig. 60E ): Clinging type; basis robust, twice as long as wide, ith two pinnate setae ventrodistally; ischium with two setae; merus with two spiniform setae ventrally; carpus with spine distally and with prickly tubercles; propodus with two spiniform setae ventrally and one dorso-distal seta, a little shorter than dactylus; dactylus three times as long as simple unguis; both almost as long as propodus.

Pereopod-6 ( Fig. 60F ): Similar to as pereopod-5, but propodus with three dorso-distal setae.

Pleopod ( Fig. 60G ): Basal article naked; exopod with one seta on inner margin and twelve plumose setae on outer margin; endopod with sixteen plumose setae on outer margin; clear gap between proximal seta and other setae.

Uropods ( Fig. 60H ): Basal article little longer than wide; both rami two-articled; exopod 0.6 times as long as endopod; proximal article little shorter than distal with one seta distally; distal article with one strong and one small seta distally; endopod proximal article 0.3 times as long as distal article; endopod distal article with one simple and two pinnate seta at middle, tipped by two long, two short and one pinnate setae distally.

Distribution: Mediterranean Sea, Sicily, Messina at a depth range of 37– 50 m.

Figures

FIGURE 58. Typhlotanais messinensis G.O. Sars, 1882, female. A), lateral view; B) dorsal view. Scale = 1 mm.

FIGURE 60. Typhlotanais messinensis, female. 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.