Babakina festiva, (ROLLER, 1972)

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 : 672-673

BABAKINA FESTIVA ( ROLLER, 1972)

( FIGS 1A , 2 , 3A )

Babaina festiva Roller, 1972: 416 , figures 1–9.

Babakina festiva ( Roller, 1972) – Roller, 1973; Gosliner, 1990; Baba, 2000.

Material examined: CASIZ 070589 , one specimen, 28 mm, dissected, California , x.1971, Shane Anderson . CASIZ 071054 , one specimen, 17 mm, collected on kelp holdfast, Paradise Cove , Malibu , Los Angeles, California, xi.1971, Shane Anderson . CASIZ 69850 , four specimens, two dissected, Matanchen , near San Blas, Nayarit, Mexico , 25.i.1975, Gary McDonald . CASIZ 067110 , one specimen, from tide pool, Fitzgerald Marine Reserve , Moss Beach, San Mateo County, 14 June 1987, Terrence M. Gosliner .

Distribution: This species is known from California and middle and northern Japan ( Roller, 1972; McDonald, 1983; Gosliner, 1990; Baba, 2000).

External morphology: The body is elongate and slender, with a trailing posterior end of the foot ( Fig. 1A ). Living animals are 10–32 mm in length. The anterior margins of the foot and tentaculiform foot corners are bilabiate and slightly notched. The body colour can range from a translucent light pink to a purple cast. A short opaque white patch extends medially from the anterior end of the head to just in front of the rhinophores. The moderately long cerata are cylindrical and taper distally. They are translucent white and the deep reddish brown digestive gland is visible in the basal two-thirds followed by a covering of succession of three subapical bands of opaque white, yellow and opaque white. The apex is translucent white. The cerata are densely clustered and continuous throughout the length of the body. There are approximately 100 cerata on either side of the body and they are not clearly divisible into distinct clusters or rows. The largest arch is the most anterior. The red-brown rhinophores share a common base, are perfoliate and have 31–43 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 have a somewhat wrinkled texture. They are the same colour as the ground colour with a lighter tip. The tentacular anterior foot corners are pinkish purple basally with a purple tip. 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 just posterior to the rhinophore base.

Buccal armature: The jaws ( Fig. 2A, B ) are tanbrown. The masticatory border contains 3–4 rows of numerous irregularly, triangular denticles. The radula formula is 13 ¥ 0.1.0 ( CASIZ 07589) and 23 ¥ 0.1.0 ( CASIZ 069850) in two specimens examined. The rachidian tooth ( Fig. 2C, D ) is broad with wide, triangular central cusp. There are 8–15 elongate, acutely pointed denticles on either side of the central cusp. The number of denticles is not equal on either side. For example, on one tooth there were 12 denticles on the right side and 15 on the left side. Some denticles share a common base and bifurcate above. In some instances denticles are present on the central cusp while in other cases they are only found laterally from the cusp.

Reproductive system: It has an androdiaulic arrangement ( Fig. 3A ). The narrow elongate preampullary duct widens into the convoluted ampulla. The ampulla consists of 2–3 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. The prostatic portion enters the wider proximal portion of the penial sac. The penial papilla is contained within the penial sac. The unarmed penial papilla is elongate and conical in shape. It narrows to a rounded apex and exists adjacent to the elongate bursa copulatrix. The oviduct is elongate and connects to the pyriform receptaculum seminis. The receptaculum is straight in the specimen from California and curved apically in the specimen from Mexico. 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 and the albumen glands are similar in size. The mucous gland is much larger than the other two female glands and exits ventral to the penis and bursa copulatrix.

Remarks: The anatomy of this species fits well with the original description by Roller (1972). Roller did not describe the reproductive anatomy and it is presented here. Its anatomy conforms largely to that described by Baba (2000). The presence of a curved receptaculum seminis and a thin bursa copulatrix are identical between the Japanese specimen described by Baba and the specimens examined here from California and Mexico. The fundamental arrangement of organs is similar to that described by Miller (1974) for B. caprinsulensis , with a proximal receptaculum seminis and a distal bursa copulatrix. This arrangement has been noted as the most plesiomorphic condition found in the Aeolidina ( Gosliner & Kuzirian, 1990; Gosliner & Willan, 1991). Some differences in reproductive anatomy between the two species are noted ( Table 1 ). The ampulla of B. festiva is much wider and less elongate than that of B. caprinsulensis . The penis of B. festiva is elongate while that of B. caprinsulensis is much shorter. The bursa copulatrix of B. festiva is thin and elongate while that of B. caprinsulensis is bulbous and recurved. In B. festiva , the receptaculum seminis is pyriform while that of B. caprinsulensis is thin and elongate.

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 2. Babakina festiva (Roller, 1972), scanning electron micrographs. A, jaw. B, detailed view of masticatory border, from Mexican specimen (CASIZ 069850). C, radular teeth of specimen from Malibu, California (CASIZ 070589). D, radular teeth of specimen from Nayarit, Mexico (CASIZ 69850).

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.