Cirolana somalia, Schotte & Kensley, 2005

Schotte, Marilyn & Kensley, Brian, 2005, New species and records of Flabellifera from the Indian Ocean (Crustacea: Peracarida: Isopoda), Journal of Natural History 39 (16), pp. 1211-1282 : 1227-1229

Cirolana somalia sp. nov.

( Figures 9 , 10 )

Material examined

Holotype: USNM 280279 , one male (11.0 mm), IIOE sta 444, off Somalia, 9 ° 369N, 51 ° 019E, 80 m, 16 December 1964 . Paratypes: USNM 280280 , two ovigerous females, one female, one juvenile, same data as holotype . USNM 280281 , two male, two ovigerous female, one female , IIOE sta 447, off Somalia, 10 ° 009N, 51 ° 159E, 59–61 m, 16 December 1964 .

Description

Body three times longer than wide. Cephalon bearing four tiny tubercles in two pairs on posterior half, posterior pair wider apart. Evenly convex dorsal interocular suture connecting posterior margins of eyes. Pereonite 1 with five to six tiny tubercles in two rows near anterior margin. Pereonites without furrows. Pleonites 3–5 with irregular number of small, low tubercles on posterior margins. Pleotelson with barely perceptible medial depression, best seen in side view; dorsal surface with scattered, tiny setules. Apex evenly rounded, armed with eight spine-like setae and plumose setae between small teeth.

Antennule, article 3 of peduncle about two-thirds length of articles 1 and 2 combined; 1 and 2 not fused; flagellum of antennule with about 15 articles. Flagellum of antenna with 42 articles, extending posteriorly to pereonite 5. Frontal lamina narrowly pentagonal, sides slightly incurved, length more than twice greatest width, acute apex not overlapped by rostral process. Maxilla 1 and 2 and mandible as figured.

Pereopod 1 with four robust and one tiny blunt setules on posterior margin of merus. Pereopod 2 merus bearing five robust and one tiny spine-like setules on posterior margin. Pereopod 7 with groups of spine-like setae at distal angles of carpus and merus. Penes present, short, separated by distance equal to about 11% of width of sternite.

Pleopod 1 with five coupling hooks and three fringed setae on peduncle. Pleopod 2 with slender appendix masculina arising basally, extending beyond endopod by about 10% of its length with scattered simple setae, apex narrowing to acute point; three coupling hooks and seven plumose setae on peduncle.

Uropods projecting slightly beyond pleotelsonic apex. Exopod slightly shorter than endopod, lateral margin having seven spine-like setules amongst plumose setae, medial margins with four setules, apex acute but not bifid. Endopod with two stiff setules and long plumose setae on lateral margin; medial margin with five setules plus plumose setae, apex not bifid.

Female. As for male except in sexual characters and absence of tubercles on cephalon and pereonite 1. Ovigerous females considerably larger than mature males.

Remarks

The new species appears very similar to another western Indian Ocean species, Cirolana theleceps Barnard, 1940 , in having a faint mid-dorsal depression on the pleotelson and tubercles on the cephalon and first pereonite of the male. The uropods and pleotelsonic apex of C. theleceps differ considerably, both uropodal rami being more rounded apically and, as in the pleotelson, armed with very blunt, almost scallop-like teeth unlike those in C. somalia .

Etymology

The species name is a noun in apposition, taken from its type locality, Somalia.

Figures

Figure 9. Cirolana somalia sp. nov. (A) Male, dorsal view; (B) male, lateral view; (C) frons; (D) maxilliped; (E) pleotelson and uropods; (F) left mandible; (G) anterior pleon in ventral view; (H) penes; (I) maxilla 2; (J) maxilla 1.

Figure 10. Cirolana somalia sp. nov. (A) Pleopod 1; (B) male pleopod 2; (C) apex of copulatory stylet; (D) pereopod 7; (E) pereopod 1; (F) dactylus of pereopod 1; (G) setae on merus of pereopod 1, enlarged; (H) pereopod 2.