Marta Pola

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.

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.

A new species of Tambja (Nudibranchia: Polyceridae: Nembrothinae) from southern Brazil

A new species of the genus Tambja Burn, 1962 is described from the western Atlantic on the coast of Brazil. To date, the genus Tambja was represented in the Atlantic Ocean by nine species but only three of them have been recorded from the western Atlantic: T. gratiosa from the Gulf of Mexico, T. divae from Brazil and T. oliva from the Caribbean coast of the Isthmus of Panama. Tambja stegosauriformis sp. nov. is easily distinguished from all its congeneric Atlantic species of the genus by having very well developed light blue tubercles scattered on the yellowish-orange ground with an elongate crest behind the gill until the end of the tail. The anterior margin of the notum is very wide and elevated and it extends into a kind of lapel around the rhinophores. This peculiar external morphology and its conspicuous coloration characterize this species.

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.

Taxonomic revision and phylogenetic analysis of the genus Tambja Burn, 1962 (Mollusca, Nudibranchia, Polyceridae)

This paper discusses the systematics and phylogeny of the genus Tambja Burn, 1962 throughout tropical and temperate areas in the Atlantic, eastern Pacific and Indo‐Pacific. The phylogenetic relationships within Tambja are unknown and a comprehensive taxonomic revision is necessary in order to construct a phylogeny of the genus. To date, Tambja comprises 28 nominal species, 22 of which have been examined morphologically based on newly collected and type material. The reproductive systems of four species (T. limaciformis (Eliot, 1908), T. sagamiana (Baba, 1955), T. amakusana, Baba, 1987 and T. olivaria, Yonow, 1993) were studied for the first time and two species previously considered as valid, Tambja morosa (Bergh, 1877) and Tambja kushimotoensis Baba, 1987, are here synonymized. Of the remaining six nominal species, no additional material has been found since their original description. The holotypes of three (T. diaphana (Bergh, 1877), T. gratiosa (Bergh, 1890) and T. marbellensis Schick & Cervera, 1998) have been re‐examined and the original descriptions improved. Tambja diaphana is regarded as nomen dubium. Tambja amitina (Eliot, 1905), T. divae (Marcus, 1958) and T. anayana Ortea, 1989 remain as valid species until further comparison with new specimens can be made. New structures are also described for several taxa. Morphological and anatomical data from 22 nominal Tambja species have been used to construct a phylogeny. The phylogenetic analysis rejects the monophyly of Tambja and shows its preliminary relationships within the subfamily Nembrothinae.

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.

Protaeolidiella atra Baba, 1955 versus Pleurolidia juliae Burn, 1966: One or two species?

Protaeolidiella atra Baba, 1955 and Pleurolidia juliae Burn, 1966 are two species traditionally regarded as the members of Aeolidiidae but recently attributed to Facelinidae. Because of their apparent similarities, Rudman (J Molluscan Stud 56:505–514, 1990) rendered P. juliae as a junior synonym of P. atra. In this paper, we conducted a review of both species and completed their descriptions with new data regarding the anatomy of the reproductive system. P. atra and P. juliae have differences in their colouration, number of cerata and characteristics of their reproductive system. Based on these differences, we conclude that these species are not conspecific and should be regarded as distinct taxa.

Burnaia Miller, 2001 (Gastropoda, Heterobranchia, Nudibranchia): a facelinid genus with an Aeolidiidae’s outward appearance

In recent years, several morphological and molecular analyses have been undertaken to study the phylogenetic systematics of Aeolidiidae members. The monospecific genus Burnaia could not be included in the previous analysis, due to the lack of material. This study includes two specimens of Burnaia helicochorda from Australia and places them in their systematic position using two mitochondrial and one nuclear genes (COI and 16S, and H3, respectively). A description of its anatomy is also included with colour pictures of the animal and scanning electron micrographs of radula and jaws. Based on our results, B. helicochorda does not belong to Aeolidiidae since it appears nested among some facelinids.

First molecular phylogeny of the subfamily Polycerinae (Mollusca, Nudibranchia, Polyceridae)

The subfamily Polycerinae includes four genera with around 46 species described to date. This subfamily is characterized by a limaciform body, which may have simple tentacular processes on the margin of the oral veil. Phylogenetic relationships between the genera of the subfamily Polycerinae (Polyceridae) have not yet been studied, and therefore, the only available information is based on morphological descriptions. The present study reports the first phylogenetic analysis of Polycerinae based on the mitochondrial genes cytochrome oxidase subunit I and the large ribosomal subunit (16S rRNA) using maximum likelihood and Bayesian methods. Our results showed that Polycerinae is monophyletic, but the relationships within the subfamily as well as within Polycera remain unresolved. A key finding of this study is that there are clearly two sympatric species of Polycera present in South Africa: Polycera capensis Quoy and Gaimard, 1824 also found in Australia and an undescribed Polycera sp. On the other hand, the studied specimens of the genus Gymnodoris were clustered within Polycerinae, reopening the problem of the systematic position of this genus. Additional genes and species of Polycerinae and Gymnodoris would provide more information and probably fully resolve this situation.