Baeolidia macleayi ( Angas, 1864 )

Carmona, Leila, Pola, Marta, Gosliner, Terrence M. & Cervera, Juan Lucas, 2014, Review of Baeolidia, the largest genus of Aeolidiidae (Mollusca: Nudibranchia), with the description of five new species, Zootaxa 3802 (4), pp. 477-514 : 484-485

Baeolidia macleayi ( Angas, 1864)

( Figs. 2 C, 3B, 4C–D, 6B)

Aeolis macleayi Angas, 1864: 65 , pl. VI, Fig. 4 .

Coryphella macleayi ( Angas, 1864) : Bergh 1878, 16. Spurilla macleayi ( Angas, 1864) : Burn 1969, 96.

Type locality. Port Jackson, New South Wales.

Type material. To our knowledge no type material remains. We designate the specimen CASIZ 0 71923 (6 mm) from Long Reef, North of Sydney, New South Wales, Australia, as the neotype in order to avoid confusion with similar species.

Material examined. Neotype: CASIZ 195247, one specimen, dissected, 6 mm in length preserved, Australia, New South Wales, North of Sydney, Long Reef, collected by Terrence M. Gosliner, 17 September 1989. Other material: CASIZ 0 71923, two specimens, dissected, 8 and 6 mm in length preserved, Australia, New South Wales, North of Sydney, Long Reef, collected by Terrence M. Gosliner, 17 September 1989.

Geographical distribution. Originally described from Port Jackson, Australia ( Angas 1864), this species is also known from New Zealand ( Burn 1962, 1969; Coleman 2001; Miller 2001; Burn 2006; Rudman 2007a).

External morphology ( Figs. 2 C, 3B): Body fairly short, broad, tapering close to posterior end of foot. Foot corners tentaculiform. Body colour translucent. Some specimens with white and lemon-yellow speckling over dorsum and head. Bright orange mark on pericardium with different intensity; it continues through head and posterior end of foot. Rhinophores ribbed ( Fig. 3 B), shorter than oral tentacles. Proximal two-thirds reddish or brownish. Distal part of rhinophores with lemon-yellow pigment. Oral tentacles translucent, may have white and lemon-yellow spots.

Cerata elongate and slender, or moderately short and bulb-shaped. Cerata translucent, being visible the brownish or bluish ramifications of digestive gland. Cnidosacs white. Cerata with bright lemon-yellow ring subapically. White spots over ceratal surface might form a second ring below the yellow one. Cerata composed of four arches and three rows, leaving a distinct gap between pre and post-pericardial groups. Each group with 3–10 cerata, decreasing in size towards foot. Anus cleioproctic, below second right row. Genital aperture below first right arch.

Anatomy. Masticatory process smooth ( Fig. 4 C). Radular formula 16 x 0.1.0 ( CASIZ 195247, 6 mm). Radular teeth bilobed with 30–40 elongate and acutely pointed denticles on either side of central cusp ( Fig. 4 D). Central cusp prominent, elongate. Oral glands spongy, moderately large, delicate, with uniform diameter throughout most of length. Oral glands dorso-laterally to buccal bulb. Salivary glands absent.

Reproductive system diaulic ( Fig. 6 B). Preampullary duct widening into moderately short ampulla. Postampullary duct dividing into oviduct and vas deferens. Vas deferens inserting into wider proximal portion of penial sac with unarmed penial papilla. Receptaculum seminis heart-shaped, short stalk connecting to short oviduct, before latter forms female glands. Vagina ventral to penis.

Remarks. We transfer Aeolis macleayi to Baeolidia because of the type of oral glands, which are exclusive of this genus in Aeolidiidae .

Excluding Baeolidia faustina (see B. faustina remarks), the colouration and the shape of the cerata distinguish B. macleayi from the remaining Baeolidia species. Regarding the radular morphology, the teeth found in B. macleayi are similar to B. rieae sp. nov., B. variabilis sp. nov. and B. gracilis sp. nov. Nevertheless, the central cusp of B. macleayi is larger than the minute central cusp found in the species mentioned above. Moreover, the shape of the receptaculum seminis is quite different between B. macleayi and B. rieae sp. nov., B. variabilis sp. nov. and B. gracilis sp. nov.: in B. macleayi it is heart-shaped; in B. rieae sp. nov. and B. variabilis sp. nov. it is bean-like, and the receptaculum seminis of B. gracilis sp. nov. is ovoid. In addition, it is worth mentioning that B. macleayi is a native species from Australia and New Zealand, whereas B. rieae sp. nov. was found in Japan, B. gracilis sp. nov. in the Philippines and B. variabilis sp. nov. is from the Philippines, Papua New Guinea and the Marshall Islands.

The oral glands of B. macleayi are first described and reported here.

Figures

FIGURE 2. Photographs of the living animals. A, B, Baeolidia moebii: (A) specimen from the Philippines, photo by Terrence M. Gosliner, CASIZ 177602; (B) specimen from Mozambique, photo by Yara Tibiriça, MNCN 15.05 / 63447; (C) Baeolidia macleayi, specimen from Australia, photo by Terrence M. Gosliner, CASIZ 71923; (D-E) Baeolidia japonica: (D) specimen from Japan, photo by Akira Kawahara, CASIZ 1814520; (E) specimen from Marshall Islands, photo by Scott Johnson, CASIZ 186795; (F) Baeolidia ransoni, specimen from the Philippines, photo by Terrence M. Gosliner, CASIZ 186208.

FIGURE 3. Different papillate rhinophores in Baeolidia: (A) from Rudman (1982); (B) from Gosliner (1985). Scale bars: A, 3 mm; B, 1 mm; C, 1.2 mm; D, 1.5 mm.

FIGURE 4. Scanning electron photographs. (A – B) Baeolidia moebii (CASIZ 180327): (A) Detailed view of the masticatory border; (B) Radular teeth; (C – D) Baeolidia macleayi (CASIZ 195247): (C) Detailed view of the masticatory border; (D) Radular teeth; (E – F) Baeolidia japonica (CASIZ 181357); (E) Detailed view of the masticatory border; (F) Radular teeth. Scale bars: A, 10 µm; B, 30 µm; C-D, 10 µm; E, 100 µm; F, 150 µm.

FIGURE 6. Reproductive system. (A) Baeolidia moebii, specimen from Mozambique (MNCN 15.05 / 63447); (B) Baeolidia macleayi, specimen from Australia (CASIZ 195247); (C) Baeolidia japonica, specimen from Marshall Islands (CASIZ 181357); (D) Baeolidia ransoni, specimen from the Philippines (CASIZ 186209). Scale bars: A – D, 0.5 mm. Abbreviations: am, ampulla; fgm, female gland mass; ps, penial sac; rs, receptaculum seminis; va, vagina; vd, vas deferens.