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DNA sequences disclose a new species of Africonus cone snail from São Vicente (Gastropoda: Conidae)
(2017)
The sequencing of complete mitochondrial genomes of cone species belonging to the (sub)genus Africonus, which is endemic to Cabo Verde, has allowed the reconstruction of phylogenetic relationships among these species, as well as delimitation and validation of their taxonomic status. While several species were found to be synonyms, some populations had enough DNA sequence divergence to merit the species status. This is the case of some populations inhabiting São Vicente, which are hereby described as a new species. The new species shares similarity in shell morphology to Africonus miruchae (Röckel, Rolán & Monteiro, 1980), endemic to Sal, due to convergence, and with Africonus denizi Afonso & Tenorio, 2011, endemic to São Vicente, due to close phylogenetic relationship. Additionally, the three species have significant differences in radular morphology.
The genus Profundiconus Kuroda, 1956 is reviewed. The morphological characters of the shell, radular tooth and internal anatomy of species in Profundiconus are discussed. In particular, we studied Profundiconus material collected by dredging in deep water during different scientific campaigns carried out in the Solomon Islands, Madagascar, Papua New Guinea and New Caledonia. We reconstructed a phylogeny of 55 individuals based on partial mitochondrial cox1 gene sequences. The phylogeny shows several clades containing individuals that do not match any of the known species of Profundiconus based on their shell and radular morphologies, and are introduced here as five new species: Profundiconus maribelae sp. nov. from the Solomon Islands; P. virginiae sp. nov. from Chesterfield Plateau (New Caledonia); P. barazeri sp. nov. from Chesterfield Plateau and the Grand Passage area (New Caledonia); P. puillandrei sp. nov. from Norfolk Ridge (New Caledonia), Kermadec Ridge (New Zealand) and possibly Balut Island (Philippines); and P. neocaledonicus sp. nov. from New Caledonia. Furthermore, Profundiconus teramachii forma neotorquatus (da Motta, 1984) is raised to specific status as P. neotorquatus (da Motta, 1984).
Although cone snails are among the most studied group of gastropods, new species are still regularly described. Here, we focus on Afonsoconus Tucker & Tenorio, 2013, a lineage that includes only two species from the Indo-Pacific Ocean. The analysis of molecular (partial mitochondrial cox1 gene sequences) and morphological (shell and radular tooth) characters revealed that the samples collected by dredging in deep water during a recent expedition carried out in the Mozambique Channel are different from the samples collected in the Pacific Ocean. We thus introduce here a new species, Afonsoconus crosnieri sp. nov., from the SW Indian Ocean including records from the Mozambique Channel, the Comoros and Glorieuses Islands, Madagascar, South Africa and Reunion Island.
In the last few years, a sharp increase in the number of descriptions of new species of West African cone snails, particularly from the Cabo Verde Archipelago, has taken place. In previous studies, we used mitogenome sequences for reconstructing robust phylogenies, which comprised in total 120 individuals representing the majority of species (69.7%) described from this biogeographical region (except Angolan endemics) and grouped into seven genera within the family Conidae. Here, we add another 12 individuals representing endemic species that were missing in the previous studies. We use the phylogenies to identify monophyletic groups and a genetic divergence threshold (0.2% uncorrected p distance) to determine the number of valid species. As a result, the number of valid West African cone species could be drastically reduced to at least 40%, indicating that some recent poor-quality descriptions loosely based on phenotypic characters prone to convergence such as the shape and color patterns of the shell have contributed substantially to taxonomic inflation. Several previously accepted species with a reduced geographical distribution now become phenotypic forms of the remaining valid species, which increase their distribution ranges. In contrast, several cryptic species are now uncovered and described. For instance, Africonus insulae sp. nov. and Kalloconus canariensis sp. nov. are hereby introduced as new species. A detailed systematic account with illustrations and relevant information is presented. Lectotypes are designated for Conus trochulus and Conus irregularis, and neotypes for Conus crotchii and Conus diminutus. According to our results, it is strongly recommended that any future introduction of new taxa names for cone snails from West Africa should be supported by molecular and/or anatomical rather than exclusively shell morphological data. The taxonomic decisions here taken have direct implications for conservation and will eventually require re-evaluation of the Red List risk status of an important number of species.
The present work reviews the deep-water cone fauna of New Caledonia and its Economic Exclusive Zone. It is based on the material collected for more than 40 years by oceanographic expeditions in the deep waters surrounding New Caledonia, organized by the Muséum national d’histoire naturelle-Paris/ORSTOM, then Institut de Recherche pour le Développement, in the framework of the Tropical Deep-Sea Benthos programme. A total of 2377 lots containing 5113 specimens collected in depths between 100 and 1260 m have been examined. About 770 specimens were collected live, and allowed for radular and DNA studies. A phylogenetic analysis, based on the cox1 gene, of the deep-water cone snail fauna of New Caledonia is presented, along with a detailed, fully illustrated taxonomic account with data on geographic and bathymetric distribution and radular morphology. A total of 76 different species of cone snails were identified among the collected material. Of these, 22 corresponded to typical shallow water species, which were most likely translocated into deeper water, whereas 54 could be considered true components of the deep water (below 100 m) cone snail fauna. Species of the genus Profundiconus represent 22%, whereas those of the genera Conasprella and Conus represent 28% and 50%, respectively. Eleven deep water cone species can be considered as endemic to the New Caledonia EEZ, representing 20.3% of the total. The most abundant species found (more than 400 specimens each) were Conus (Afonsoconus) bruuni, Conasprella (Boucheticonus) alisi, Conasprella (Conasprella) boucheti, and Profundiconus vaubani. The new species Conus (Taranteconus) samadiae sp. nov. is hereby described.