Haliotis mykonosensis Owen, Hanavan & Hall, 2001 in the Procida Island (Gulf of Naples) and in the Central Mediterranean Sea, with notes on the Mediterranean HALIOTIDAE

Seventeen living specimens of Haliotis mykonosensis Owen, Hanavan & Hall, 2001 are reported from the area between the wharf of Sancio Cattolico and Punta di Pioppeto (northern side of Procida Island, Naples) and twenty-six from further Central Mediterranean localities. The species was known up to now from the original description only and this note contributes to a better understanding of its real distribution in the Mediterranean Sea

The alien fissurellid Diodora ruppellii (G. B. Sowerby I, 1835): a first record for Libya from Tripoli Harbour

The mollusc Diodora ruppellii (G. B. Sowerby I, 1835) (Gastropoda: Lepetellida: Fissurellidae) is reported here for the first time as an alien species in Libyan coastal waters. Field surveys conducted throughout the winter period of 2018–2019 along the sandy shoreline bordering Tripoli Harbour yielded fourteen empty shells and one live specimen, all found within accumulating shell middens. While the finding of D. ruppellii in close proximity to Tripoli Harbour may allude to its introduction via shipping traffic, natural dispersal from nearby, known or yet undiscovered, Mediterranean populations cannot be ruled out. The current study forms part of a larger ongoing programme investigating the marine fauna of the littoral zone with a focus on the identification of non-native species. As D. ruppellii is so far recorded from Libya as based on the present punctiform record, we rank it here as a casual (i.e. not established) species in the country

New records of alien and cryptogenic marine bryozoan, mollusc, and tunicate species in Libya

New records of alien and cryptogenic invertebrate marine species in Libya are reported here based on field surveys conducted from June to November 2018, in a shallow bay next to the city of Tripoli. Those identified here include the cerithiid gastropod Cerithium scabridum Philippi, 1848, the goniodoridid sea slug Okenia longiductis Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli and Crocetta, 2019, the “spaghetti bryozoan” Amathia verticillata (delle Chiaje, 1822), and the ascidian Symplegma brakenhielmi (Michaelsen, 1904)

First documented record of the invasive cockle Fulvia fragilis (Forsskal in Niebuhr, 1775) (Mollusca: Bivalvia: Cardiidae) in Libya

The occurrence of the fragile cockle Fulvia fragilis (Forsskål in Niebuhr, 1775) in Libyan coastal waters (south-eastern Mediterranean Sea) is reported here for the first time based on the collection of twenty-nine live specimens from the shoreline in close vicinity to Tripoli Harbour, situated to the west of the country. The present record fills a gap in the geographic range of F. fragilis – its occurrence is already documented from the neighbouring territories of Egypt, Italy, Malta, and Tunisia. Although there are no certainties regarding the precise arrival date of this non-native bivalve in Libyan coastal waters, its presence within the environs of Tripoli Harbour might allude to its facilitated spread through ballast water from commercial shipping activity

First record of Aplysia dactylomela Rang, 1828 (Mollusca: Gastropoda) in Libyan coastal waters

The spotted sea hare Aplysia dactylomela Rang, 1828 is reported from four locations in Libyan coastal waters. The direct observation reported here resulted from a field survey of sea snails in the coastal environs of Tripoli, to the west of the country, while the remaining records result from postings made on the Facebook (TM) social media website, made by recreational spear-fishermen who took images and filmed specimens at Abo Fatma beach and Misrata, to the west of the country, and also at sites close to Benghazi and Al Hamamah, to the east of the country. This is the first record of A. dactylomela in Libyan waters

Insights into the role of deep-sea squids of the genus Histioteuthis (Histioteuthidae) in the life cycle of ascaridoid parasites in the Central Mediterranean Sea waters

Ascaridoid nematodes comprise a wide range of heteroxenous parasites infecting top fish predators and marine mammals as definitive hosts, with crustaceans, squids, and fishes acting as intermediate/paratenic hosts. Limited data exist on the species and role of several intermediate and paratenic hosts in the life cycle of these parasites. In the aim of adding knowledge on the role of squid species in their life cycle, we have here investigated the larval ascaridoid nematodes collected from the deep-sea umbrella squid Histioteuthis bonnelli and the reverse jewel squid Histioteuthis reversa captured in the Central Mediterranean Sea (Tyrrhenian Sea). Morphological study and sequence analysis of the internal transcribed spacer (ITS) regions of the ribosomal DNA (rDNA) and the mitochondrial cytochrome c oxidase subunit 2 (mtDNA cox2) gene locus revealed the occurrence of Anisakis physeteris and of an unidentified species of the genus Lappetascaris. Sequence analysis revealed that specimens of Lappetascaris from both squid species matched at 100% sequences previously deposited in GenBank from larval ascaridoids collected in octopuses of the genus Eledone of the Mediterranean Sea. The Bayesian inference tree topology obtained from the analysis of the fragments amplified showed that Lappetascaris specimens were included in a major clade comprising Hysterothylacium species collected in fishes of the families Xiphiidae and Istiophoridae. As regards the site of infection in the squid host species, A. physeteris larvae predominated (60.7%) in the gonads, while those of Lappetascaris (76.3%) were found infecting the mantle musculature. The overall high values of parasitic load suggest both squid species as transmitting hosts of third stage larvae of Lappetascaris to top predator fishes, as well as the umbrella squid as an intermediate/paratenic host in the life cycle of A. physeteris in the Mediterranean Sea

Evolución de la comunidad de moluscos del lago Sabaudia: causas antropogénicas

The evolution of the molluscan biota in Sabaudia Lake (Italy, central Tyrrhenian Sea) in the last century is hereby traced on the basis of bibliography, museum type materials, and field samplings carried out from April 2009 to September 2011. Biological assessments revealed clearly distinct phases, elucidating the definitive shift of this human-induced coastal lake from a freshwater to a marine-influenced lagoon ecosystem. Records of marine subfossil taxa suggest that previous accommodations to these environmental features have already occurred in the past, in agreement with historical evidence. Faunal and ecological insights are offered for its current malacofauna, and special emphasis is given to alien species. Within this framework, Mytilodonta Coen, 1936, Mytilodonta paulae Coen, 1936 and Rissoa paulae Coen in Brunelli and Cannicci, 1940 are also considered new synonyms of Mytilaster Monterosato, 1884, Mytilaster marioni (Locard, 1889) and Rissoa membranacea (J. Adams, 1800). Finally, human-driven environmental changes and cumulative anthropogenic pressures proved to be the whole driver of the constitution of the human-induced malacofauna studied, casting doubts on the correct use of the definition of "native fauna"

New records of the genus Pachygrapsus (Crustacea : Decapoda) from the central Mediterranean Sea with a review of its Mediterranean zoogeography

The occurrence of Pachygrapsus maurus and Pachygrapsus transversus is reported from the Maltese Islands for the first time on the basis of one specimen of P. maurus collected in 1990 and numerous recent specimens, and the distribution of the two species is mapped. The controversial presence of P. maurus in Italy is confirmed and two new sites for this species are reported, including the first for the mainland of Italy. The examination of the historical specimen of P. maurus from the Genova area revealed a misidentification of P. transversus; this record could be a result of ship-mediated transport. First notes on the habitat of P. maurus in the central Mediterranean Sea are given. Updated maps of the distribution of P. maurus and P. transversus in the Mediterranean are provided and the zoogeography of these species is revisited.peer-reviewe

The protected taxon Ocypode cursor (Linnaeus, 1758)(Crustacea : Decapoda : Ocypodidae) - documenting its well-established presence in the Central Mediterranean

Ocypode cursor (Linnaeus, 1758) is the only Ocypode species present in the Mediterranean Sea, and one of the nine marine crustacean species protected in the basin. It is widely distributed in the eastern Mediterranean, but knowledge about its presence in the central Mediterranean is very limited so far. We hereby first document the established presence of O. cursor in the central Mediterranean (Sicily and Malta), backdate the known presence of this taxon in Italy, and offer preliminary observations on the main known Maltese population. In Sicily, O. cursor is distributed along most of the south-western coast of the island of Sicily, whilst at least three beaches in the Maltese Islands are known to support populations of this species. The main Maltese population exhibits numerous similarities (e.g. burrow width, zonation along the beach) to another Mediterranean population studied in northern Cyprus, although occurring at lower densities. We conclude that the species has been probably present within the study area for a long period, but went undetected in view of the low population densities at which it previously occurred, the lack of a comprehensive census for the species within the same study area, and its nocturnal habits. The presence of this species in the central Mediterranean seems to be attributable to secondary natural spreading.peer-reviewe