Juan Lucas Cervera

A Tale That Morphology Fails to Tell: A Molecular Phylogeny of Aeolidiidae (Aeolidida, Nudibranchia, Gastropoda)

Aeolidida is one of the largest clades of nudibranchs with at least 560 known species. However, its systematics has not been studied in a comprehensive manner. Phylogenetic analyses of larger clades such as Nudibranchia or Cladobranchia have usually included a poor sample of aeolids. Furthermore, phylogenetic studies at the family or generic level in Aeolidida are a few and far between. The first molecular phylogeny of the aeolid family Aeolidiidae is presented here. This study, the most comprehensive for Aeolidida to date, uses new sequences of two mitochondrial (COI and 16S) genes and one nuclear gene (H3). 251 specimens from members of seven families of Aeolidida, including 39 species of Aeolidiidae were studied. Excluding Pleurolidia juliae, Aeolidiidae is monophyletic. Our results resolve the systematic relationships within the Aeolidiidae at a generic level, requiring changes in the systematics of this family. Spurilla, Anteaeolidiella, Limenandra and Aeolidia are well-supported and monophyletic clades. Aeolidiella stephanieae is transferred to Berghia and Aeolidiopsis ransoni and Spurilla salaamica to Baeolidia, to maintain the monophyletic lineages reflected in this study. The systematics of Cerberilla remains unclear. Some species earlier attributed to Aeolidiella are now grouped in a previously unnamed clade that we designate as Bulbaeolidia gen. nov.

Analytical solvent sublation of metallic dithizonates. Part I. Solvent sublation of copper

The analytical applicability of the solvent sublation technique was investigated in connection with the separation and pre-concentration of trace metals combined in the form of dithizonates. Sodium lauryl sulphate was used as a collector in connection with dithizone solutions in isobutyl methyl ketone. Under suitable experimental conditions the process allows for the quantitative separation of trace amounts of copper through the easy handling of large liquid samples of up to several litres. Several experimental parameters were studied and optimised including pH, co-ligand to collector ratio and flow-rate of carrier gas. The influence of background salinity was also studied.

The end of a long controversy: systematics of the genus Limenandra (Mollusca: Nudibranchia: Aeolidiidae)

Limenandra Haefelfinger and Stamm 1958 is a small genus within the Aeolidiidae with, until this paper, only two species: Limenandra nodosa Haefelfinger and Stamm 1958 and Limenandra fusiformis Baba 1949. Although most recent authors have regarded Limenandra as a junior synonym of Baeolidia Bergh 1888, recent molecular studies have demonstrated its monophyletic status and have rejected the circumtropical distribution attributed to the type species, L. nodosa. The present paper reviews the previously known species of Limenandra with additional morphological data and describes three new species: Limenandra barnosii sp. nov. and Limenandra rosanae sp. nov. from the Indo-Pacific are easily distinguished from all other Limenandra species by their vivid and bright colour patterns, while Limenandra confusa sp. nov., also from the Indo-Pacific, is very similar to the Atlantic and Mediterranean L. nodosa. The five species differ in colouration, the size and ornamentation of the cerata, the rhinophorial papillae, details of the reproductive system and the number of salivary glands. Additionally, Limenandra can be easily distinguished from other Aeolidiidae based on differences in the radular and receptaculum seminis morphology.

Molluscan diversity in the North Atlantic Ocean: new records of opisthobranch gastropods from the Archipelago of the Azores

New findings of opisthobranch gastropods are reported to the Azores resulting from fieldwork undertaken in the islands of Faial and Sao Jorge (Central Group, Azores) during August 2007. Intertidal and subtidal areas down to 35 metres deep were sampled. Forty-four species were collected and eight are new records to the Azores, namely Chelidonura africana, Odontoglaja sabadiega, Aplysia juliana, Elysia flava, Thuridilla picta, Doris sticta, Catriona maua and Taringa armata . This increases the diversity of opisthobranchs in the archipelago to 141 species. Our results provide further support for the closer affinity of the Azorean marine diversity with the eastern Atlantic/Mediterranean Sea biota (75% of species) but they also show a biogeographic bound with the Caribbean province (25% of common species).

A test of color-based taxonomy in nudibranchs: Molecular phylogeny and species delimitation of the Felimida clenchi (Mollusca: Chromodorididae) species complex

Traditionally, species identification in nudibranch gastropods relies heavily on body color pattern. The Felimida clenchi species complex, a group of brightly colored Atlantic and Mediterranean species in the family Chromodorididae, has a history of exceptional controversy and discussion among taxonomists. The most widely accepted hypothesis is that the complex includes four species (Felimida clenchi, F. neona, F. binza and F. britoi), each with a characteristic body color pattern. In this study, we investigated the taxonomic value of coloration in the Felimida clenchi complex, using molecular phylogenetics, species-delimitation analyses (ABGD, GMYC, PTP), haplotype-network methods, and the anatomy of the reproductive system. None of our analyses recovered the traditional separation into four species. Our results indicated the existence of three species, a result inconsistent with previous taxonomic hypotheses. We distinguished an undescribed species of Felimida and redefined the concepts of F. clenchi and F. binza, both highly polychromatic species. For the first time, molecular data support the existence of extreme color polymorphism in chromatic nudibranch species, with direct implications for the taxonomy of the group and its diversity. The polychromatism observed in the F. clenchi complex apparently correlates with the regional occurrence of similar color patterns in congeneric species, suggesting different mimicry circles. This may represent a parallel in the marine environment to the mechanisms that play a major role in the diversification of color in terrestrial and fresh-water chromatic groups, such as heliconian butterflies.

Going further on an intricate and challenging group of nudibranchs: description of five novel species and a more complete molecular phylogeny of the subfamily Nembrothinae (Polyceridae)

Nembrothinae is a colourful subfamily of nudibranch polycerids, which despite its large size and striking appearance, needs to be more thoroughly studied. The available scientific information about this subfamily is very recent, and pictures of living undescribed species become available every day. Nevertheless, the lack of associated material for morphological, anatomical, and molecular analysis results in scarce additional studies. In this paper, five novel species are described: Roboastra ernsti sp. nov., Roboastra nikolasi sp. nov., Tambja brasiliensis sp. nov., Tambja crioula sp. nov., and Tambja kava sp. nov. In addition, Tambja divae (Marcus, 1958), a species previously known only from the original description, is redescribed and additional data and comments on Tambja cf. amakusana Baba, 1987 and Tambja marbellensis Schick and Cervera, 1998 are provided. Molecular data (H3, COI and 16S genes) for all these novel species and some additional ones were obtained and included in a previous molecular database. Maximum‐likelihood, maximum‐parsimony and Bayesian analyses were carried out. The phylogeny presented here has revealed Nembrothinae to be an intricate and challenging group of nudibranchs to study. Intermediate missing species seem to be critical to understanding the evolutionary relationships within this group.

A descriptive study of some Antarctic notaspidean opisthobranchs (Gastropoda), with description of a new genus and species

During the expedition “ANTARTIDA 9101”, organized by the Spanish Oceanographic Institute to the South Orkney Islands, four specimens of notaspidean gastropods were collected. Three of them have been identified as Bathyberthella antarctica Willan and Bertsch, 1987. However, one specimen, although externally similar to B. antarctica, had an internal anatomy exhibiting features that have enabled us to consider it to be a new genus and species. This new taxon is characterized by the presence of jaws without mandibular elements, and a vaginal gland that partially surrounds the distal region of the vaginal duct. In this paper the new genus and species is described. Additional anatomical data of the specimens of B. antarctica collected during the expedition are also included.

Anatomical and taxonomical studies of the Antarctic nudibranchsAustrodoris kerguelenensis (Bergh, 1884) andA. georgiensis n. sp. from the Scotia Sea

During the expedition “ANTARTIDA 8611” to the Scotia Sea, organized by the Spanish Oceanographic Institute, several specimens ofAustrodoris were collected. Although nearly all have been identified asAustrodoris kerguelenensis (Bergh, 1884), one of them shows some anatomical features, mainly related to the reproductive system, that allows us to identify this specimen as a new species, which we have namedA. georgiensis. Therefore, with the aim of clarifying the taxonomical value of this species, a comparative study of the anatomy ofA. kerguelenensis andA. georgiensis is presented. Some new data on the diet ofA. kerguelenensis are also presented.

Review of Baeolidia , the largest genus of Aeolidiidae (Mollusca: Nudibranchia), with the description of five new species

Twenty species of the subgenus Pedionis occurring in the Chinese fauna are recognized, including two new species, P. aculeata sp. nov., P. papillata sp. nov. from Guizhou Prov., China. And, P. nankunshanensis Li, Dai & Li, 2011 is here considered as a junior synonym of P. yunnana Zhang & Viraktamath, 2010. A key to Chinese species of subgenus Pedionis is also provided as well as a checklist.

Description of two new phanerobranch nembrothid species (Nudibranchia: Polyceridae: Doridacea)

Two new species of dorid nudibranchs of the genus Tambja are described from the Indo-Pacific and the temperate waters of the western Atlantic. Tambja haidari sp. nov. is only known from the type locality in Senegal. This species has dark blue ground colour with yellow bands and sky-blue spots, which become real tubercles along the tail. The internal features are typical of species of the genus, with rachidian teeth that lack denticles and with a prostate slightly differentiated from the rest of the vas deferens. Tambja blacki sp. nov., from Papua New Guinea and eastern Australia, has yellow-green or green colour with black blotches. There are two large blotches on the head continuing from the inner side of the base of the rhinophores towards the rear. The notal margin is elevated and joins behind the gill in a well-developed hump. The reproductive system of this species is very characteristic because it has some features more typical of species of Nembrotha than of Tambja (i.e. vaginal gland absent, prostate spread over the bursa copulatrix and wide and elongate vagina). These descriptions bring the number of species of Tambja found around the world to 31.