Baeolidia ransoni ( Pruvot-Fol, 1956 )

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 : 487-489

Baeolidia ransoni ( Pruvot-Fol, 1956)

( Figs. 2 F, 6D, 7A–B)

Aeolidiopsis ransoni Pruvot-Fol, 1956: 228 , Fig. 1 .

Type locality. Kaukura Atoll, French Polynesia.

Type material. To our knowledge no type material exists. We designate the specimen CASIZ 0 65417 from North of Madang, Papua New Guinea, as the neotype in order to avoid confusion with similar species.

Material examined. Neotype: CASIZ 0 65417, one specimen, dissected, 3 mm in length preserved, Papua New Guinea, North coast, North of Madang, collected by Richard C. Willan, 31 January 1988. Other material: CASIZ 0 65300, one specimen, dissected, 10 mm in length preserved, Papua New Guinea, North coast, North of Madang, collected by Richard C. Willan, 31 January 1988; CASIZ 186209, one specimen, dissected, 7 mm in length preserved, Philippines, Luzon, Batangas Province, Calumpan Peninsula, Balayan Bay, collected by Terrence M. Gosliner, 28 April 2011; CASIZ 186208, one specimen, Philippines, Luzon, Batangas Province, Calumpan Peninsula, Balayan Bay, collected by Terrence M. Gosliner, 28 April 2011.

Geographical distribution. First described for Kaukura Atoll, French Polynesia ( Pruvot-Fol 1956), it is also known from the Indo-Pacific ( Australia, Papua New Guinea and the Philippines) (Gosliner et al. 2008), Japan ( Nakano 2004; Ono 2004) and Hawaii ( Pittman & Fiene 2012a).

External morphology ( Fig. 2 F): Body broad, large, tapering close to posterior end of foot. Foot corners rounded. Body colour translucent with small light ochre and medium bright white spots all over. Density of spots varies. Rhinophores smooth, translucent with ochre pigment. Apex white. Oral tentacles short, slender, tapering near apices. Oral tentacles translucent with small light ochre and medium bright white spots. Cerata flattened, almost leaf-like. Cerata large, closely oppressed to the body surface rather than erect. Cerata translucent with small light ochre and medium bright white spots. Tips translucent. Cerata up to twenty-three rows. Each row contains 1–4 cerata, decreasing in size towards the foot. Anus acleioproctic, dorsally to notal brim. Gonopore located among cerata of anteriormost group on right.

Anatomy. Masticatory edge smooth ( Fig. 7 A). Radular formulae 11 x 0.1.0 ( CASIZ 186209, 7 mm) and 13 x 0.1.0 ( CASIZ 0 65417, 3 mm). Radular teeth pectinate, short with 18–46 elongate, acutely pointed denticles from side to side, without a notch or central cusp ( Fig. 7 B). Oral glands absent. Salivary glands present.

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

Remarks. The other two Palythoa feeders, Baeolidia harrietae ( Rudman, 1982) and B. palythoae Gosliner, 1985 , were transferred and ascribed to Baeolidia respectively by Gosliner (1985). However, Aeolidiopsis ransoni was retained as the sole species of Aeolidiopsis because of its acleioproctic anus dorsal to the notal brim (Pruvot- Fol 1956; Gosliner 1985; Miller 2001). Carmona et al. (2013) showed that, from a molecular point of view, the position of the anus and the rhinophoral ornamentation are not significant phylogenetically in Baeolidia . Hence, Aeolidiopsis ransoni was transferred to Baeolidia .

Only B. harrietae and B. palythoae have some resemblance with B. ransoni in their colouration, the reticulate pattern of the digestive gland and the cerata lying out the body. However, the smooth rhinophores of the latter species distinguish B. ransoni from B. harrietae and B. palythoae . The teeth of B. ransoni are a diagnostic character for this species ( Fig. 7 B). Teeth of B. ransoni lack a central cusp or central notch, are quite arched, pectinate, and have elongate and acutely pointed denticles from side to side. So far, this radular morphology has not been found in any other Baeolidia species.

This species was included in the molecular study by Carmona et al. (2013) ( Fig. 1 ).

Figures

FIGURE 1. Phylogeny of Baeolidia, based on Carmona et al. (2013). Names on right side of vertical bars refer to revised classification.

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 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.

FIGURE 7. Scanning electron photographs. (A – B) Baeolidia ransoni (CASIZ 065417); (A) Detailed view of the masticatory border; (B) Radular teeth; (C – D) Baeolidia salaamica (CASIZ 184524); (C) Detailed view of the masticatory border; (D) Radular teeth. Scale bars: A, 50 µm; B, 100 µm; C, 50 µm; D, 150 µm.