Roboastra, CABOVERDENSIS POLA ET AL., 2003

Pola, M., Cervera, J. L & Gosliner, T. M., 2005, Review of the systematics of the genus Roboastra Bergh, 1877 (Nudibranchia, Polyceridae, Nembrothinae) with the description of a new species from the Galápagos Islands, Zoological Journal of the Linnean Society 144 (2), pp. 167-189 : 180

ROBOASTRA CABOVERDENSIS POLA ET AL., 2003

( FIGS 3E , 4E, G- I , 6D , 7F, G )

Material examined: Holotype: 15 miles NW Santo Antao Island, Cape Verde Archipelago , July 2002, 1 specimen, 38 m depth ( CASIZ 166047 ) . Other material: Tarrafal, Cape Verde Archipelago , December 1998, 1 specimen, 25 mm, P.Wirtz ( MMF 35083) . Banco Joao Valente, Boavista Island , Cape Verde Archipelago, August 2002, 2 specimens, 20 m depth, 26/ 30 mm (70 mm in life), M.A. Malaquias ( MNCN. 15.05/46614). Banco Joao Valente , Boavista Island , Cape Verde, August 2002, 2 specimens, 30 m depth, 31/ 37 mm (70 mm in life), M.A. Malaquias ( CASIZ 166052 ) . Boavista Island , August 2002, 3 specimens, 13/15/ 18 mm, C. Grande ( MNCN. 15.05/46617). Sao Vicente, Cape Verde, October 2002, 1 specimen, 20 mm, G. Calado ( CASIZ 166050 ) . Specimens were collected on rocks and were measured preserved.

Distribution: This species is known only from the Cape Verde Archipelago.

External and internal morphology: Described in detail and figured by Pola et al. (2003) and not repeated here. A specimen from Tarrafal, Cape Verde Archipelago, is illustrated ( Fig. 6D ) to confirm the identity of the material examined. The radular formula of two specimens of 70 mm (in life) is 33 ¥ 3– 4.1.1.1.3–4 ( Fig. 7F ). The rachidian tooth is broad, clearly curved at the base, having three well-differentiated cusps. The inner lateral tooth is hooked with two well-developed elongate cusps. The inner one is very long, with sharp and curved edges on the inner side and a prominent projection on the outer one. The outer lateral teeth (3–4) are smaller and quadrangular without prongs, and decrease in size from the inner to the outer side of the radula.

The reproductive system is shown in Figure 3E . The hermaphroditic duct has an S-shaped ampulla that continues into the spermoviduct. The vas deferens is long and coiled, with a uniform width. It is slightly narrower in the prostatic part. It ends in a dilated penial section. The penis is armed with at least three different kinds of spines arranged in helicoidal rows. Types of spines and their arrangement on the penis are shown in Figure 4G- I and E , respectively. The bursa copulatrix is rounded and the seminal receptacle is elongate; both are similar in size. The seminal receptacle joins the vagina near the bursa via a short duct. The vagina is short and straight, opening into the genital atrium, near the vaginal gland. This gland is very well developed, flattened, with muscular walls.

Remarks: This species is the second to be described from the Atlantic Ocean. Roboastra caboverdensis is very similar to R. europaea ( García Gómez, 1985) , but some external and internal features permit us to distinguish it from its congeneric Atlantic species. The two species differ in their colour pattern. The arrangement of the yellow lines differs in both species; it is denser in R. europaea . The base of the rachidian radular tooth is more curved in R. caboverdensis than in R. europaea . The upper cusp of the inner lateral tooth is simple in R. caboverdensis and bifid in R. europaea (see Fig. 7E ). R. caboverdensis has been reported feeding on other polycerids, such as Tambja fantasmalis (Malaquias, pers. comm.). This species has been misidentified as T. ambja simplex in http://www. medslug.de and a picture of it is also shown in Wirtz & Debelius (2003) identified as Roboastra sp. nov.

Figures

Figure 3. Drawings of reproductive systems of Roboastra spp. A, R. gracilis. B, R. luteolineata. C, R. tigris. D, R. europaea (adapted from Pola et al., 2003). E, R. caboverdensis. F, R. leonis sp. nov. Scale bar = 1 mm. Abbreviations: am, ampulla; bc, bursa copulatrix; fglm, female gland mass; ga, genital atrium; p, penis; pr, prostate; rs, receptaculum seminis, ud, uterine duct; va, vagina; vd, vas deferens; vgl, vaginal gland.

Figure 4. Penial morphology of Roboastra spp. A, R. gracilis (CASIZ 087131), scale bar = 30 Mm; B, R. luteolineata (CASIZ 115739), scale bar = 30 Mm. C, R. tigris (NHMLAC 140747), scale bar = 300 Mm. D, R. europaea (MNCN 15.05/46613), scale bar = 50 Mm. E, R. caboverdensis (MNCN 15.05/46614), scale bar = 90 Mm. F, R. leonis sp. nov. (CASIZ 097577), scale bar = 300 Mm. G-I, detail of the three different kinds of spines in R. caboverdensis (MNCN 15.05/46614), scale bar = 10 Mm. J, T. morosa (CASIZ 142786; 35 mm preserved), scale bar = 20 Mm.

Figure 6. Photographs of living animals: A, Roboastra luteolineata, Papua New Guinea (photo T.M. Gosliner). B, R. tigris, Mar de Cortés (photo H. Debelius). C1, R. europaea, Carroñera, Spain (light form) (photo L. Tocino). C2, R. europaea, Tarifa, Spain (black form) (photo T.M. Gosliner. D, R. caboverdensis, Cape Verde (photo P. Wirtz). E, R. leonis sp. nov., the Galápagos Islands (photo T.M. Gosliner).

Figure 7. Scanning electron micrographs of the radula. A, right half of the radula, Roboastra luteolineata (CASIZ 115739), scale bar = 300 Mm. B, innermost lateral teeth, R. luteolineata (CASIZ 086319), scale bar = 30 Mm. C, left half of the radula, R. tigris (CASIZ 057321), scale bar = 300 Mm. D, outermost lateral teeth, R. tigris (CASIZ 068357), scale bar = 90 Mm. E, innermost lateral teeth, R. europaea (CASIZ 166053); white lines indicate the bifid upper cusp of some inner teeth, scale bar = 200 Mm. F, right half of the radula, R. caboverdensis (MNCN 15.05/46614), scale bar = 300 Mm. G, innermost lateral teeth, R. caboverdensis (MNCN 15.05/46614), scale bar = 90 Mm. H, right half of the radula, R. leonis sp. nov. (CASIZ 097577), scale bar = 300 Mm.