Babakina anadoni, (ORTEA, 1979)

Gosliner, Terrence M., González-Duarte, Manuel M. & Cervera, Juan Lucas, 2007, Revision of the systematics of Babakina Roller, 1973 (Mollusca: Opisthobranchia) with the description of a new species and a phylogenetic analysis, Zoological Journal of the Linnean Society 151 (4), pp. 671-689 : 676-678

BABAKINA ANADONI ( ORTEA, 1979)

( FIGS 1C , 3C , 4 )

Rioselleolis anadoni Ortea, 1979: 132 .

Babakina anadoni – Rolán et al., 1991: 115.

Babakina festiva – misidentification, Padula & Absalão, 2005: 99.

Material examined: MNCN 15.05 /46702, one specimen, dissected, 13 mm in length preserved, 15 m depth, Isla de Tarifa, southern Iberian Peninsula (36°00′48″N,; 05°36′W), 5.ix.2003 , César Megina. MNCN 15.05 /46703, two specimens, 12 and 13 mm in length preserved, one dissected, 10 meters depth, Cabo de Trafalgar , southern Iberian Peninsula (36°11′N, 06°01′W), 25.vi.1994 , César Megina. MNCN 15.05 /46, one specimen, 25 mm in length alive, Punta Segaño , Galicia, northern Iberian Peninsula (43°27′24″N, 8°18′25″W), 25.v.2005 , Fátima Martins. MNCN 15.05 /46979, one specimen, intertidal zone, Pedras Negras , Galicia, northern Iberian Peninsula (42°27′N, 08°56′W), 31.iii.2006 , A. Luque. MNCN 15.05 /46705, two specimens, 2 and 5 mm in length preserved, one dissected, Güimar , Tenerife, Canary Islands (28°18′N, 16°21′W), 30.x.2004 , Leopoldo Moro. MNCN 15 ./46706, one specimen, dissected, 10 mm in length alive, 1 m depth, Thurstone Bay , Abaco, Bahamas (26°42′28″N, 77°18′63″W), 29.vi.1999, C. Redfern . IBUFRJ 14229 , one specimen, dissected, 11 mm in length alive, 1 m depth, Praia das Conchas , Cabo Frio, Río de Janerio, Brazil (22°52′46″S; 42°01′07″W), 13.xi.2004 , V. Padula.

Distribution: Originally described from the northern Spain ( Ortea, 1979; Rolán et al., 1991), this species has also been reported from southern Spain (García-Gómez, 1987; Cervera et al., 2006), southern Portugal ( Cervera et al., 2006), Canary Islands ( Pérez Sánchez & Moreno, 1990; Moro et al., 1995, 2003; Ortea et al., 2001, 2003; present study), Bahamas ( Redfern, 2001; present study) and Brazil ( Padula & Absalão, 2005).

External morphology: The body is elongate and slender, with a short posterior end of the foot ( Fig. 1C ). Living animals are 10–25 mm in length. The anterior margin of the foot is elongate, tentaculiform foot corners are bilabiate and slightly notched. The body colour is dull violet but can range from a translucent light pink to purple. A short opaque white or yellowish patch extends medially from the anterior end of the head to just behind the rhinophores. The moderately long cerata are cylindrical and taper distally. They are dark blue, with a yellow upper and unequal dorsolateral surface as well as a subapical orange band. The apex is translucent white. The cerata are densely distributed and are arranged in 22–30 oblique rows, extending from the rear of rhinophores almost to the end of the foot, even continuing along the lateral sides of the pericardial area. Each row contains 2–4 cerata, with the larger ones being situated more dorsally and decreasing in size towards the foot.

The rhinophores have a more intense violet colour than the ground colour of the body, but the apex and the anterior side of the rachis are pale yellow. They share a common base, are perfoliate and have 20–29 lamellae each. The apex and a line that runs medially along the posterior face of each rhinophore is yellowish white. The oral tentacles are elongate and acutely pointed. They are the same colour as the ground colour with an opaque white tip. The tentacular anterior foot corners are pinkish purple throughout. The pleuroproctic anus is located ventral to the notal brim about one-third of the body length from the anterior end. The nephroproct is anterior to the anus. The genital aperture is located below notal brim between the fourth and ninth cerata.

Buccal armature: The jaws ( Fig. 4A, B ) are tanbrown. The masticatory border of the jaws bears 2–4 rows of denticles that increase in number and size towards the edge. The radular formula of the five dissected specimens is 18 ¥ 0.1.0. ( MNCN 15.05/ 46706), 14 ¥ 0.1.0 ( MNCN 15.05/46705), 14 ¥ 0.1.0 ( MNCN 15.05/46703), 16 ¥ 0.1.0 ( MNCN 15.05/46702) and 29 ¥ 0.1.0 ( IBUFRJ 14229). The rachidian tooth ( Fig. 4C, D ) is broad with narrow, triangular central cusp. There are 6–10 elongate, acutely pointed denticles on either side of the central cusp. The number of denticles is equal on either side. None of the denticles shares a common base. No denticles are found laterally from the cusp and in no instance extend onto the cusp.

Reproductive system: It has an androdiaulic arrangement ( Fig. 3C ) and was examined in four specimens (two from the Strait of Gibraltar: MNCN 15.05/46702, MNCN 15.05/46703, one from the Canary Islands: MNCN 15.05/46705, one from the Bahamas: MNCN 15./46706 and one from Brazil: IBUFRJ 14229). All were virtually identical in all aspects of their morphology. The narrow elongate preampullary duct widens into the convoluted ampulla. The ampulla consists of two folds and narrows again before dividing into the oviduct and vas deferens. The vas deferens widens into a glandular prostatic portion that consists of numerous convolutions that cover the penial sac. The prostatic portion enters the wider proximal portion of the penial sac. The unarmed penial papilla is contained within the penial sac, and it is elongate and conical in shape, and the sac is usually curved. It narrows to rounded apex and exists adjacent to the rounded, straight bursa copulatrix. The oviduct is elongate and connects to the pyriform receptaculum seminis. The other portion of the oviduct emerges from the base of the receptaculum and, after a short distance, enters the small albumen gland. The membrane gland is similar in size than the albumen gland. The mucous gland is much larger than the other two female glands and exits ventral to the penis and bursa copulatrix.

Remarks: The external morphology and colouration of Babakina anadoni were described from of a single specimen from the northern Spain ( Ortea, 1979). Ortea erected the new genus Rioselleolis to accommodate this species and considered that this genus should be included in a separate family, without proposing a new family. Rolán et al. (1991) transferred this species to the genus Babakina , based on additional material and personal communications with R. Roller.

Our specimens match the external appearance described by Ortea (1979), although some Canarian specimens appear to have a lighter ground body colouration than those from the coast of Spain. Moreover, the features of the radula and jaws described by Rolán, Rolán-Alvarez & Ortea (1991) fit well with those specimens dissected here from eastern and western Atlantic. The reproductive system is described for the first time here, and does not vary significantly in any of the specimens examined. Redfern (2001) collected a single specimen of Babakina from Bahamas (western Atlantic), which attributed to B. festiva . He described the external appearance only, which is very similar to specimens from the eastern Atlantic. The internal anatomy of Redfern’s specimen (present study), as well as that of the Brazilian specimens, agrees with that of B. anadoni collected from the eastern Atlantic. Thus, we conclude that his specimen belongs to this species rather than B. festiva .

Gosliner (1990) questioned whether the three nominal species of the genus are distinct and may refer only to one biological species. However, after completing a comparative examination of material it is evident that B. anadoni is a valid species. Externally, B. anadoni can be recognized from other species by the presence of a subapical band of yellow followed by another more distal band of orange. This species has symmetrically arranged denticles on either side of the central cusp as in B. caprinsulensis . The other two species have an asymmetrical arrangement of denticles. Several reproductive characters clearly distinguish this species from other Babakina ( Table 1 ). The penis of B. anadoni is elongate as in B. festiva . However, the bursa copulatrix is rounded as in B. caprinsulensis , except that the duct is straight in B. anadoni rather than curved.

Figures

Figure 1. A, Babakina festiva (Roller, 1972), living animal, Fitzgerald Marine Reserve, San Mateo County California, photo by T. M. Gosliner. B, Babakina caprinsulensis Miller, 1974, living animal, Poor Knights Islands, North Island, New Zealand, photo by I. Skipworth. C, Babakina anadoni (Ortea, 1979), living animal, Algarve, Portugal, photo by Jose Augusto Silva. D, Babakina indopacifica sp. nov., living animal, Mindanao, Philippines, photo by T. M. Gosliner.

Figure 3. Reproductive anatomy. A, Babakina festiva (Roller, 1972), specimen CASIZ 069850, scale = 1.0 mm. B, Babakina caprinsulensis Miller, 1974, after Miller (1974). C, Babakina anadoni (Ortea, 1979), from Bahamian specimen, MNCN 15./46706. Scale bar = 0.3 mm. D, Babakina indopacifica sp. nov., specimen from Mindanao, Philippines. Scale bar = 0.5 mm. Abbreviations: am = ampulla, bc = bursa copulatrix, fgm = female gland mass, od = oviduct, p = penis, rs = receptaculum seminis, vd = vas deferens.

Figure 4. Babakina anadoni (Ortea, 1979), scanning electron micrographs. A, jaw, specimen from Tarifa, Spain (MNCN 15.05/46702). B, masticatory border, specimen from Bahamas (MNCN 15./46706). C, radular teeth, specimen from Tarifa, Spain (MNCN 15.05/46702). D, radular teeth, specimen from Bahamas, MNCN 15./46706.