Aliens in changing seascapes: a newly reported non-native sacoglossan (Mollusca, Heterobranchia) in the western Mediterranean Sea

We report the discovery of the Indo-Pacific sacoglossan Elysia nealae Ostergaard, 1955 from northeastern Sardinia (Central Tyrrhenian Sea). This is the first record of this species in the western Mediterranean Sea and only the second for the whole of the Mediterranean Sea following a report from Cape Epanomi, Greece. We discuss the identification of this species as well as the expansion of its geographical range. Data on the ecology and behavior of E. nealae leads us to hypothesize that the increase in the Mediterranean’s water temperature due to climate change has favored this non-native species and contributed to its expanded distribution

First record of the genus Dermatobranchus van Hasselt, 1824, in the Mediterranean Sea (Nudibranchia: Arminidae)

Three individuals of a nudibranch belonging to the genus Dermatobranchus (Arminidae) were found at a depth of 3 meters, in a bottom with sand and gravel, during night SCUBA diving activity in Porto Pirrone, Leporano (Taranto, Apulia, Italy). The external morphology and coloration of these Mediterranean individuals clearly resemble those of D. rubidus (Gould, 1852), a species known only from the central and western Pacific Ocean. This is the first record of the genus Dermatobranchus van Hasselt, 1824 for the Mediterranean Sea

Tritonia nilsodhneri marcus Ev., 1983 (Gastropoda, heterobranchia, tritoniidae): First records for the adriatic sea and new data on ecology and distribution of mediterranean populations

The nudibranch Tritonia nilsodhneri, usually feeding on a variety of gorgoniacean species, is known from different localities of the eastern Atlantic Ocean and the Mediterranean Sea. Knowledge of the host preferences of the Mediterranean populations is still scarce. Few records of this nudibranch have been reported from the eastern Mediterranean basin. With this report, the occurrence of T. nilsodhneri within the Mediterranean basin is extended to the Adriatic Sea. Furthermore, the list of the host species associated to the Mediterranean populations for feeding habits is increased from two up to five. Mediterranean specimens of T. nilsodhneri were observed for the first time feeding and spawning on Leptogorgia sarmentosa, Eunicella cavolini and E. labiata. Finally, these last two Gorgoniidae species are also reported here as a new host species for T. nilsodhneri

Molecular and morphological data provide evidence for only one alien species of pearl oyster in the Mediterranean Sea

Taxonomic identification of alien bivalve species in the Mediterranean Sea can be challenging because of high morphological variability and the occurrence of cryptic species complexes, as in the case of pearl oysters. While the presence of the Lessepsian species Pinctada radiata is well-established in the eastern Mediterranean Sea, the presence of P. fucata was recently suggested based on morphological data. In this study we performed an integrative assessment based on morphological and genetic data on pearl oysters collected across the Mediterranean Basin. Molecular species delimitation and phylogenetic analyses allowed a straightforward taxonomic assignment of all collected specimens to P. radiata. These specimens show the entire suite of morphological character states considered diagnostic of either P. fucata or P. radiata by previous studies. This finding clearly demonstrates that these morphological characters have no taxonomic value, and their variability observed in specimens from the Mediterranean Sea represents (part of) the intraspecific variability of P. radiata. While no evidence has been found for the presence of P. fucata, the earlier occurrences of P. radiata from the eastern and southern Mediterranean Sea are complemented with verified occurrence in the western and northern regions, demonstrating a further spreading of this non-native species throughout the Mediterranean Sea. This study clarifies the taxonomic identification and geographical distribution of pearl oysters in the Mediterranean Sea and substantiates the importance of molecular identification of alien bivalves characterized by extensive variation in shell characters

Sympatric sibling species: The case of Caloria elegans and Facelina quatrefagesi (Gastropoda: Nudibranchia)

The aeolid nudibranch Caloria elegans (Facelinidae) is quite common in the Mediterranean Sea and eastern Atlantic Ocean and is easily recognized by the presence of a typical black spot at the apical portion of its cerata. Facelina quatrefagesi (Facelinidae) was long considered as a synonym of C. elegans until recently, when it was re-evaluated as a valid species based mainly on rhinophore morphology. In order to definitively assess the status of these aeolid taxa, we employed an integrative taxonomy approach using the nuclear H3 and the two mitochondrial cytochrome oxidase subunit I and 16S markers. The molecular analyses clearly showed that, although morphologically closely related to C. elegans, F. quatrefagesi is a valid species

SEM/EDX analysis of stomach contents of a sea slug snacking on a polluted seafloor reveal microplastics as a component of its diet

Understanding the impacts of microplastics on living organisms in aquatic habitats is one of the hottest research topics worldwide. Despite increased attention, investigating microplastics in underwater environments remains a problematic task, due to the ubiquitous occurrence of microplastic, its multiple modes of interactions with the biota, and to the diversity of the synthetic organic polymers composing microplastics in the field. Several studies on microplastics focused on marine invertebrates, but to date, the benthic sea slugs (Mollusca, Gastropoda, Heterobranchia) were not yet investigated. Sea slugs are known to live on the organisms on which they feed on or to snack while gliding over the sea floor, but also as users of exogenous molecules or materials not only for nutrition. Therefore, they may represent a potential biological model to explore new modes of transformation and/or management of plastic, so far considered to be a non-biodegradable polymer. In this study we analysed the stomachal content of Bursatella leachii, an aplysiid heterobranch living in the Mar Piccolo, a highly polluted coastal basin near Taranto, in the northern part of the Ionian Sea. Microplastics were found in the stomachs of all the six sampled specimens, and SEM/EDX analyses were carried out to characterize the plastic debris. The SEM images and EDX spectra gathered here should be regarded as a baseline reference database for future investigations on marine Heterobranchia and their interactions with microplastics

Notulae to the Italian flora of algae, bryophtes, fungi and lichens: 16

In this contribution, new data concerning algae, bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the algal genera Acetabularia, Nitella, and Nitellopsis for the bryophyte genera Drepanocladus, Fissidens, Hookeria, and Weissia, the fungal genera Alnicola, Arthonia, Cortinarius, Inocybe, Leucoagaricus, Neohygrocybe, and Puccinia and the lichen genera Bacidina, Chaenotheca, Flavoplaca, Gyalecta, Heterodermia, Rinodina, Scytinium, and Squamarina