Baeolidia gracilis Carmona, Pola, Gosliner & Cervera, 2014, sp. nov.
Creators: name: Carmona, Leila
name: Pola, Marta
name: Gosliner, Terrence M.
name: Cervera, Juan Lucas
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Nudibranchia
Aeolidiidae
Baeolidia
Baeolidia gracilis

description: Baeolidia gracilis sp. nov.
LSID urn:lsid:zoobank.org:act:A50C22AD-2E31-4D77-841F-7DEF78087E20 (Figs. 12 B, 13A–B, 14A)
Berghia sp. 2: Gosliner et al. 2008, 404.
Material examined. Holotype: CASIZ 0 83766, one specimen, dissected, 9 mm in length preserved, Philippines, Luzon, Batangas Province, Calumpan Peninsula, Maricaban Strait, collected by Terrence M. Gosliner, 22 February 1992.
Type locality and habitat. Arthur's Rock (South West side of Calumpan Peninsula), Maricaban Strait, Calumpan Peninsula, Batangas Province, Luzon, Philippines. Found under coral rubble in 10 m of water.
Geographical distribution. Thus far, known only from the Philippines (present study).
Etymology. The specific name refers to the slender body of this species.
External morphology (Figs. 12 B): Body moderately elongate, tapering close to translucent posterior end of foot. Foot corners rounded. Head and pericardium dark greyish blue. Posterior part of notum and cerata ochre. Iridescent greyish blue and bright ochre pigment over pericardium. Reticulate brown pattern close to foot edges. Rhinophores approximately equal in length to oral tentacles. Rhinophores dark greyish blue with only few moderately short papillae, mainly in posterior part. Oral tentacles short, slender, tapering near apices. Oral tentacles with same colour as rhinophores.
Cerata long, flattened, pod-bean-like. Cerata with greenish ochre net, converging on translucent apex. Inner margin with opaque white line. Cerata in three arches followed by five rows, leaving a distinct gap between prepericardial group and post-pericardial groups. Each group with 1–9 cerata, decreasing in size towards foot. Anus cleioproctic, below second right arch. Gonopore among cerata of anteriormost group on right.
Anatomy. Masticatory process smooth (Fig. 13 A). Radular formula 9 x 0.1.0 (CASIZ 0 83766, 9 mm). Radular teeth bilobed with 48–63 elongate, acutely pointed denticles on either side of notch (Fig. 13 B). Two pairs of oral glands. Oral glands delicate. First pair elongate, laying dorso-laterally to buccal bulb. Second pair smaller, rounded, emptying on ventral side of head. Salivary glands absent.
Reproductive system diaulic (Fig. 14 A). Preampullary duct widening into 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 moderately large, ovoid, short stalk connecting to short oviduct, before latter forms female glands. Vagina ventral to penis.
Remarks. While most of the Baeolidia species have a stout body, Baeolidia gracilis sp. nov. is much more slender than the others members of this genus (see e.g. Fig. 12). The cerata of this species are also particular. They are long, flattened and pod-bean-like rather than being leaf-like. This morphological features and its colour pattern characterize this species. Regarding colouration, B. gracilis sp. nov. most closely resembles B. rieae sp. nov. and B. lunaris sp. nov.. However, B. gracilis sp. nov. has a white line on the inner margin of the cerata that is not present in B. rieae. sp. nov. Moreover, B. rieae sp. nov. lacks the second pair of oral glands of B. gracilis sp. nov.. The latter species does not have the white spot close to the base of cerata of B. lunaris sp. nov.. Both species also differ in the radular morphology (see Fig. 11 E–F for B. lunaris sp. nov. and 13A–B for B. gracilis sp. nov.). In terms of internal anatomy, in addition to this new species, only B. variabilis sp. nov. and B. palythoae have two pairs of oral glands. B. variabilis sp. nov. and B. gracilis sp. nov. have consistent differences in colouration, while B. palythoae has papillae over the masticatory border, which is smooth in B. gracilis sp. nov..
description: Published as part of 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, pp. 477-514 in Zootaxa 3802 (4) on pages 500-501, DOI: 10.11646/zootaxa.3802.4.5, http://zenodo.org/record/249605