Baeolidia moebii Bergh, 1888

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 : 479-483

Baeolidia moebii Bergh, 1888

( Figs. 2 A–B, 3A, 4A–B, 5, 6A)

Baeolidia moebii Bergh, 1888: 778 , pl. LXXIX, Figs. 10–16 , pl. LXXX, Figs. 1–4 . Baeolidia major Eliot, 1903: 252 .

Baeolidia major amakusana Baba, 1937: 335 .

Berghia major ( Eliot, 1903) : Edmunds 1969, 467, Fig. 10 . Spurilla major ( Eliot, 1903) : Rudman 1982, 169, Figs. 18 –19.

Type locality. Grand Bay, Rodrigues Island, Mauritius.

Type material. To our knowledge no type material remains. We designate the specimen MNCN 15.05/63447 from Mozambique as the neotype in order to avoid confusion with similar species.

Material examined. Neotype: MNCN 15.05/63447, one specimen, dissected, 18 mm in length preserved, Mozambique, Zavora Bay, collected by Yara Tibiriça, January 2012. Other material: CASIZ 177602, one specimen, dissected, 10 mm in length preserved, Philippines, Luzon Island, Batangas Bay, Calumpan Peninsula, collected by Terrence M. Gosliner, 16 April 2008; CASIZ 157017, two specimens, dissected, 25 and 24 mm in length preserved, Philippines, Luzon Island, Batangas Province, Balayan Bay, Seafari Beach, collected by Ángel Valdés and Mary James Adams, 12 May 2001; CASIZ 186211, one specimen, dissected, 10 mm in length preserved, Philippines, Luzon, Batangas Province, Calumpan Peninsula, Batangas Bay, collected by Alicia Hermosillo, 0 4 May 2011; CASIZ 180327, one specimen, dissected, 6 mm in length preserved, Hawaii, Maui, Airport Beach, collected by Cory Pittman, 0 4 October 2008; CASIZ 0 76055, one specimen, dissected, 16 mm in length preserved, Mexico, Baja California, Gulf of California, San Jose Island, Punta Colorado, collected by Antonio J. Ferreira 15 July 1971.

Geographical distribution. Originally described from Mauritius ( Bergh 1888), it is also known from the Seychelles (Gosliner et al. 2008), Tanzania ( Eliot 1903; Edmunds 1970), Mozambique (present study), the Reunion Island ( Bidgrain 2013), Australia ( Cobb & Mullins 2013), Indonesia (Gosliner et al. 2008), the Philippines (Gosliner et al. 2008), Japan ( Baba 1933b, 1937, 1955; Ono 1999, 2004; Nakano 2004) and the Marshall Islands (present study). This species is also found in the Eastern Pacific: Hawaii ( Kay 1979; Gosliner 1980), tropical Pacific North America (Gosliner et al. 2008) and Mexico ( Farmer 1966). Recently, it has also been reported in Turkey ( Turk & Furlan 2011).

External morphology ( Figs. 2 A–B, 3A): Body large, broad, tapering gradually towards posterior end of foot. Foot corners tentaculiform. Body colour variable, commonly greyish white or brownish green ( Fig. 2 A). Some specimens reddish ( Fig. 2 B). Background colour brownish green, overlaid with reticulate ochre pattern. Dorsum usually with bright white patches. Whitish or yellow ring on anteriormost edge of head, continuing towards oral tentacles and forming a distinct light band; both, ring and band, may be interrupted. Rhinophores, oral tentacles and foot corners same as body colour. Rhinophores shorter than oral tentacles. Rhinophores studded with minute knobs ( Fig. 3 A); apex white. Oral tentacles with white tips.

Cerata length variable. Cerata flattened, almost leaf-like. Branches of digestive gland brownish-green, shining through translucent body wall. Whitish patches on outer side of cerata, probably with bright yellow marks. Cerata usually with bright yellow subapical band and just below it a purplish area. Apex translucent white. Cerata composed of up to nine arches, leaving a distinct gap between pre and post-pericardial groups. Each arch with 4–15 cerata, decreasing in size towards foot. Anus cleioproctic, within second right arch. Genital opening placed among cerata of anteriormost group on right side.

Anatomy. Masticatory border of jaws smooth ( Fig. 4 A). Radular formulae 17 x 0.1.0 ( MNCN 15.05/ 63447, 18 mm), 19 x 0.1.0 ( CASIZ 0 76055, 16 mm), 20 x 0.1.0 ( CASIZ 177602, 10 mm) and 22 x 0.1.0 ( CASIZ 180327, 6 mm). Radular teeth bent upwards with up to 100 elongate, fine and acutely pointed denticles from side to side, without central notch or central cusp ( Fig. 4 B). Teeth progressively smaller towards posterior region of radula. Oral glands fragile, small and spongy, lying dorso-laterally to buccal bulb ( Fig. 5). Oral gland morphology variable, from rounded to elongate. Salivary glands large.

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

Remarks. This species has not been studied under the name of Baeolidia moebii since its original description ( Bergh 1888). When Eliot (1903) described B. major , he pointed out that the latter could be merely a full-grown individual of B. moebii since the main difference between both species was the size. Nevertheless, Eliot (1903) finally described B. major as a valid species, owing to the ambiguities in the original description of B. moebii . Taking into consideration Eliot’s statements together with the proximity of both type localities ( Mauritius for B. moebii and Zanzibar for B. major ), Carmona et al. (2013) considered B. major as a junior synonym of B. moebii . Neither Bergh (1888) nor Eliot (1903) mentioned the presence of oral glands in B. moebii . Only Rudman (1982) pointed out the existence of salivary glands in this species. Two of our specimens possessed oral glands, and salivary glands were found twice. This variability could be an artefact of the state of preservation of these specimens. An alternative hypothesis could be an intraspecific variation for these two characters, which has also been observed in Limenandra nodosa ( Carmona et al. 2014c).

Despite the large variability in colouration, our specimens identified as Baeolidia moebii match with the information given by Bergh (1888) and Eliot (1903) as well as with more recent descriptions ( Edmunds 1969; Gosliner 1980; Rudman 1982). Gosliner (1985) stated the presence of a penial gland in the reproductive system of B. moebii (identified as Berghia major ). The only aeolidiid where this condition has been described is Limenandra nodosa ( Schmekel 1970) , although Carmona et al. (2014c) did not find any traces of a penial gland. Since none of the specimens here examined exhibited this structure, the existence of a penial gland for B. moebii is not confirmed ( Fig. 6 A).

Finally, excluding Baeolidia australis (see B. australis remarks), B. moebii colouration is clearly distinguishable from the remaining species of this genus. In terms of internal anatomy, the radular morphology of Baeolidia moebii is quite particular since teeth are bent and do not have any central notch or denticle. So far, only B. australis and B. lunaris sp. nov. have similar radular teeth. Baeolidia moebii and B. lunaris sp. nov. differ in size ( B. moebii is larger than B. lunaris sp. nov.), and rhinophorial ornamentation ( B. lunaris sp. nov. has elongate papillae instead of minute knobs and colouration). Additionally, the ampulla of B. moebii is larger than the ampulla found in B. lunaris sp. nov. Differences between B. moebii and B. australis are recorded in B. australis remarks.

This species was studied molecularly 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 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.

FIGURE 10. Photographs of the living animals. (A) Baeolidia rieae sp. nov., specimen from Japan, photo by Jum Imamoto, CASIZ 184525; (B – C) Baeolidia variabilis sp. nov.: (B) specimen from Marshall Islands, photo by Scott Johnson, CASIZ 187741; (C) specimen from the Philippines, photo by Terrence M. Gosliner, CASIZ 177715.

FIGURE 11. Scanning electron photographs. A, B, Baeolidia rieae sp. nov. (CASIZ 184525); (A) Detailed view of the jaw; (B) Radular teeth; (C – D) Baeolidia variabilis sp. nov. (CASIZ 177715); (C) Detailed view of the masticatory border; (D) Radular teeth; (E-F) Baeolidia lunaris sp. nov. (CASIZ 099221); (E) Detailed view of the masticatory border; (F) Radular teeth. Scale bars: A, 30 µm; B, 100 µm; C, 2 µm; D, 10 µm; E, 10 µm; F, 20 µm.

FIGURE 12. Photographs of the living animals. (A) Baeolidia lunaris sp. nov., specimen from Tanzania, photo by Terrence M. Gosliner, CASIZ 099221; (B) Baeolidia gracilis sp. nov., specimen from the Philippines, photo by Terrence M. Gosliner, CASIZ 083766; (D) Baeolidia scottjohnsoni sp. nov., specimen from Marshall Islands, photo by Scott Johnson, CASIZ 184503.

FIGURE 13. Scanning electron photographs. (A – B) Baeolidia gracilis sp. nov. (CASIZ 083766); (A) Detailed view of the masticatory border; (B) Radular teeth; (C – D) Baeolidia scottjohnsoni sp. nov. (CASIZ 184503); (C) Detailed view of the masticatory border; (D) Radular teeth. Scale bars: A, 3 µm; B, 10 µm; C, 50 µm; D, 100 µm.

FIGURE 14. Reproductive system. (A) Baeolidia gracilis sp. nov., specimen from the Philippines (CASIZ 083766); (B) Baeolidia scottjohnsoni sp. nov., specimen from Marshall Islands (CASIZ 184503). Scale bars: A, 0.5 mm; B, 1 mm. Abbreviations: am, ampulla; fgm, female gland mass; ps, penial sac; rs, receptaculum seminis; v, vagina; vd, vas deferens.

FIGURE 15. Schematic representation of differences of body shape among the genera Spurilla (A), drawing of Ascensión Cespedosa; Berghia (B), drawing of Ascensión Cespedosa; Limenandra (C), taken from Haefelfinger & Stamm (1958); and Baeolidia (D), taken from Rudman (1982).

FIGURE 16. Comparison of the radular morphology among the genera Spurilla (A), Berghia (B), Limenandra (C) and Baeolidia (D).

FIGURE 18. Map of the range of the different species of Spurilla, Berghia, Limenandra, and Baeolidia. A. Berghia and Limenandra. B. Spurilla and Baeolidia. Abbreviation: Isolated records of Baeolidia cryporos (star) and Spurilla braziliana (square).