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Abstract

The occurrence of the opisthobranchs Diaphana globosa, Hermaeopsis variopicta, Doris bertheloti, Rostanga rubra, Janolus cristatus and Flabellina bulbosa in the Azores is reported for the first time. Our findings expand the known geographical distribution of these species in the north-east Atlantic Ocean and increase the known diversity of opisthobranchs in the archipelago to 150 species. These results provide further support for the well-documented affinity of the Azorean marine biota to the eastern Atlantic and Mediterranean coasts.

Abstract

The marine cryptogenic species Aplysia dactylomela was recorded in the Mediterranean Sea in 2002 for the first time. Since then, this species has rapidly colonized the eastern Mediterranean, successfully establishing stable populations in the area. Aplysia dactylomela is a heterobranch mollusc found in the Atlantic Ocean, and commonly known as the spotted sea hare. This species is a voracious herbivorous with generalist feeding habits, possessing efficient chemical defence strategies. These facts probably promoted the acclimatation of this species in the Mediterranean ecosystems. Here, we report three new records of this species in the Balearic Islands and Catalan coast (NE Spain). This data was available due to the use of citizen science platforms such as GROC (Catalan Opisthobranch Research Group). These are the first records of this species in Spain and the third in the western Mediterranean Sea, thus reinforcing the efficient, fast, and progressive colonization ability of this sea hare. We have demonstrated that citizen science is a valuable tool for the early awareness of new colonizations as well as for monitoring the advance and settlement of new populations of cryptogenic species.

Abstract

Three specimens of Lomanotus barlettai were found while scuba diving at Sveta Marina (Labin, Croatia, Adriatic Sea). It is the first record from the Adriatic Sea and the third for the whole Mediterranean Sea, after those reported from the Catalan coast of Spain.

Abstract

The colonization of foreign species into the Mediterranean Sea has increased in number and geographic coverage over the past decades. For instance, the marine mollusc Haminoea cyanomarginata has scattered across the Central and Eastern Mediterranean since its description in the Red Sea by Heller and Thompson in 1983. In this study, we add the first records of the species in the Western Mediterranean basin and review the progression of its colonization from the Red Sea. The new records were obtained through the online database of the NGO called Catalan Opisthobranch Research Group (Spain), thus highlighting how citizen science platforms can provide an early warning for marine scientists and managers in relation to exogenous species.

Abstract

Nudibranchs are beautiful creatures with marvellous colour patterns that, quoting T. E. Thomson (1976), they are to the molluscs what the butterflies are to arthropods or orchids to angiosperms. For instance, four Felimida species belonging to the “luteorosea” colour group from the NE Atlantic and the Mediterranean Sea show a yellow spotted pattern above a purple mantle background, i. e. F. luteopunctata, F. luteorosea, F. rodomaculata, F. rolani. While the monophyly of F. luteorosea and F. luteopunctata has been recently recovered using molecular markers, the phylogenetic status of the elusive F. rodomaculata, endemic from the Canary Islands, has never been assessed in molecular studies. Although F. rodomaculata presents a different chromatic pattern, the lack of sound distinctive morpho-anatomical differences led some authors to suggest this species is a junior synonym of F. luteopunctata. Here, we aim to solve the controversial taxonomic status of F. rodomaculata. We conducted an integrative approach based on molecular phylogenetics and morphological analysis, including specimens collected at the type locality. Our results indicate that F. rodomaculata is, in fact, a chromatic variation of F. luteopunctata. Our study reinforces recent evidence of body colour variability within some chromodoridid nudibranchs and the need of caution in the use of this as a diagnostic character in the taxonomy of the group.

Abstract
The systematics of the gastropod clade Umbraculida, particularly the family Tylodinidae, has been a matter of debate. The Tylodinidae of the Mediterranean Sea is a case in point, with no comprehensive molecular assessment of diversity having been carried out to date. Several species and genera have been erected and synonymized in the course of the last two centuries and only a single species from each of the genera Tylodina and Anidolyta are considered to be present in these waters. In order to shed light on the controversial taxonomy of the group, we carried out both morpho-anatomical study and molecular analyses using fragments of two mitochondrial genes, cytochrome c oxidase subunit I and 16S rRNA, and the nuclear gene histone H3. Phylogenetic analyses and species delimitation tests clearly recovered two independent lineages of Tylodina from the Mediterranean and Eastern Atlantic coast, the type species T. perversa and the resurrected T. rafinesquii. We found clear differences in shell and radular morphology between both species, as well as differences in their habitat and food preferences. Interestingly, we found strong evidence that T. rafinesquii is sister to T. fungina from the Eastern Pacific rather than to the sympatric T. perversa. Furthermore, the new morphological data strongly encourage the suppression of the genus Anidolyta, which should be considered a junior synonym of Tylodina.