Monitoring the spread of non-indigenous species is fundamental to study global warming effects on marine biodiversity. A valuable tool is represented by the continuous updating of the geographic range expansion of non-indigenous species. Lamprohaminoea ovalis is a Lessepsian mollusc initially recorded in the Mediterranean Sea in 2001. This paper reports its range expansion over the last 20 years related to water warming. The first record of Lamprohaminoea ovalis from the Ligurian Sea (NW Mediterranean) is also reported. Two individuals (about 10 mm length) were observed on a sub-vertical rocky bottom at 26 m depth displaying potential trailing behaviour. This recent finding extends the currently known distributional range of Lamprohaminoea ovalis, representing the northernmost occurrence of this non-indigenous species in the western Mediterranean Sea.

Although Aplysia depilans is a widely known European species and the type species of the genus, the distinctions that separate it from other related congeners are not entirely clear. Aimed at improving this scenario, a detailed morphological description is performed herein, showing some unprecedented and useful features. Based on our anatomical examination, this study has found the opaline gland to be dark in colour, as well as a metapodium with an indistinctly delimited pedal sucker, a crop divided into two equal chambers of similar volume by a circular muscle, gizzard plates arranged in groups, and a peculiar penial sheath structure. All of these characters appear to be significantly different from the other species, based on a review of the anatomical literature and several examined samples of ongoing studies. Our central objective is to provide new data on the anatomy of the type species of Aplysiidae; and, based on topological evidence, to propose a new terminology and possible homologies to some important characters, such as parapodia lobation, cephalic tentacles, crop, penial sheath, gizzard plates and visceral ganglion in anaspideans, for future phylogenetic analysis. The subgenus Subaplysia Medina, Collins & Walsh, 2005 is regarded as a junior synonym of subgenus Aplysia Linnaeus, 1767.

The Brazilian Northeastern coast includes diverse ecosystems, particularly mangroves, coral and sandstone reefs. Although apparently high, the biodiversity of marine invertebrates from the State of Alagoas is still poorly documented. This study presents 28 new records of opisthobranch molluscs from Alagoas, 11 of which are also new records from the Brazilian Northeastern coast. In addition to comprising an important addition to knowledge about Alagoas reef biodiversity, the new records are useful data for future investigations such as biogeographical studies. Therefore, a list of all opisthobranch species known to date from Alagoas, as well as colour photographs of 32 species is provided.