Biogeographical homogeneity in the eastern Mediterranean Sea - I: the opisthobranchs (Mollusca: Gastropoda) from Lebanon

Abstract

A reviewed knowledge of the opisthobranch species from Lebanon (eastern Mediterranean Sea), based on literature records (scattered throughout various papers published over a period of more than 150 years) and recently collected material (1999-2002 within the CEDRE framework and other samples), is presented, yielding a total number of 35 taxa recorded from the Lebanese shores identified to species level. Special emphasis has mainly been given to the alien species, for which scattered notes are also given. The known opisthobranch biota is composed of 22 native (~ 63%), 12 alien (~ 34%) and one cryptogenic (~ 3%) taxa. Eleven of these (Berthella aurantiaca, B. ocellata, Aplysia fasciata, Felimare picta, Felimida britoi, F. luteorosea, F. purpurea, Phyllidia flava, Dendrodoris grandiflora, D. limbata and Aeolidiella alderi) constitute new records for the Lebanese fauna, whilst the examined material of a further seven species (Elysia grandifolia, Pleurobranchus forskalii, Aplysia dactylomela, Bursatella leachii, Syphonota geographica, Goniobranchus annulatus, Flabellina rubrolineata) anecdotally cited from Lebanon on the basis of the samples here studied, is here first explained. One additional taxon belonging to the genus Haminoea has been identified to genus level only. Despite the searching effort poning the basis of the material analyzed here, data reported clearly suggest that strong investments are still needed for a better understanding of the eastern Mediterranean opisthobranch fauna.

New Mediterranean Biodiversity Records (July 2015)

“…Özcan et al, 2010), Lebanese (Crocetta et al, 2013), and Israeli specimens (Pasternak et al, 2011). Coloration agrees with all specimens from the Mediterranean (e.g.…”

“…After its first occurrence in the Mediterranean, in a rock pool on the island of Salamina, Saronikos Gulf, Greece in 2004 (Daskos & Zenetos, 2007), the species has been found along the Mediterranean coasts of Turkey, at Beldibi, Antalya (2008) (Pasternak et al, 2011 and references within); in Lebanon (Crocetta et al, 2013); and in Greece, island of Kastelorizo, in 2010 .…”

“Opisthobranch” (mollusks) inventory of the Faro Lake: a Sicilian biodiversity hot spot

“…The other introduced species, namely Polycera hedgpethi, Melibe viridis, Haminoea cyanomarginata and Chelidonura fulvipunctata, did not show invasive behavior. A further suspected NIS, Tayuva lilacina, is provisionally considered a cryptogenic species, in agreement with Crocetta et al (2013) and authors cited within.…”

“…The 47 species (24 "occasional", 20 "settled", and three "invasive") reported for the small Faro Lake represent a remarkable data set, with respect to the whole Mediterranean (248 "opisthobranch" species listed by Sabelli et al 1990) as well as some regional inventories (35 taxa from Lebanon, in Crocetta et al 2013). Such a high number of species is particularly impressive if compared with the "quite rich" "opisthobranch" fauna (more than 20 species) reported for the widest Sicilian lagoon, the "Stagnone di Marsala", by Cattaneo Vietti and Chemello (1991).…”

New Mediterranean Biodiversity Records (December 2017)

“…Within the framework of the CEDRE project (French-Lebanese cooperation programme 1999-2002), a review of "opisthobranchs" from Lebanon was previously published based on both published and unpublished data (Crocetta et al, 2013). On a better screening of the material and photos collected, with the aim to publish a general review of Lebanese marine biota (G. Bitar, in preparation), an overlooked photo depicting a sea slug was found.…”