A quest for the lost types of Lophiotoma (Gastropoda: Conoidea: Turridae): integrative taxonomy in a nomenclatural mess

International audienc

Tracking the Near Eastern origins and European dispersal of the western house mouse

Abstract: The house mouse (Mus musculus) represents the extreme of globalization of invasive mammals. However, the timing and basis of its origin and early phases of dispersal remain poorly documented. To track its synanthropisation and subsequent invasive spread during the develoment of complex human societies, we analyzed 829 Mus specimens from 43 archaeological contexts in Southwestern Asia and Southeastern Europe, between 40,000 and 3,000 cal. BP, combining geometric morphometrics numerical taxonomy, ancient mitochondrial DNA and direct radiocarbon dating. We found that large late hunter-gatherer sedentary settlements in the Levant, c. 14,500 cal. BP, promoted the commensal behaviour of the house mouse, which probably led the commensal pathway to cat domestication. House mouse invasive spread was then fostered through the emergence of agriculture throughout the Near East 12,000 years ago. Stowaway transport of house mice to Cyprus can be inferred as early as 10,800 years ago. However, the house mouse invasion of Europe did not happen until the development of proto urbanism and exchange networks — 6,500 years ago in Eastern Europe and 4000 years ago in Southern Europe — which in turn may have driven the first human mediated dispersal of cats in Europe

Assembly of the mitochondrial genome of the hydrothermal vent crab Segonzacia mesatlantica and detection of potential nuclear pseudogenes

International audienceWe assembled the mitogenome of the Bythograeid crab Segonzacia mesatlantica, using long-range amplification of the mitochondrial genome. The mitogenome is 15,521 base pair long (33.8% A, 21.7% C, 10.5% G, 34%T) with 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNAs and a 624 bp AT-rich region. The gene arrangement is similar to other Brachyuran species. A whole genome shotgun sequencing approach revealed the presence of mitochondrial pseudogenes in the nuclear genome. This fifth mitogenome for a species of Bythograeidae should help resolve the puzzling question of the evolutionary origin of a family limited to deep-sea hydrothermal vents

Not all spotted cats are leopards: evidence for a Hemilienardia ocellata species complex (Gastropoda: Conoidea: Raphitomidae)

The small conoidean Hemilienardia ocellata is one of the easily recognizable Indo-Pacific "turrids", primarily because of its remarkable eyespot colour pattern. Morphological and molecular phylogenetic analyses revealed four species that share this "characteristic" colour pattern but demonstrate consistent differences in size and shell proportions. Three new species - Hemilienardia acinonyx sp. nov. from the Philippines, H. lynx sp. nov. from Papua New Guinea and H. pardus sp. nov. from the Society and Loyalty Islands - are described based on the results of phylogenetic analyses. Although the H. ocellata species complex clade falls in a monophyletic Hemilienardia, H. ocellata and H. acinonyx sp. nov. possess a radula with semi-enrolled or notably flattened triangular marginal teeth, a condition that diverges substantially from the standard radular morphology of Hemilienardia and other raphitomids

Too familiar to be questioned? Revisiting the Crassispira cerithina species complex (Gastropoda: Conoidea: Pseudomelatomidae)

Crassispira cerithina (Anton, 1838) is a common shallow water conoidean gastropod species, broadly distributed throughout the Indo-West Pacific. It has a distinctive shell morphology and has been referred to in many publications. It is also the first species of its family to have been studied from the viewpoint of toxinology. However, our molecular phylogenetic analysis based on fragments of the COI and 28 S rRNA genes reveals the existence of two closely related distinct species, one of which is described as new (C. scala n. sp.). These two species are sympatric in several regions of the Indo-Pacific-in the Philippines, Papua New Guinea, Vanuatu and New Caledonia. They can be reliably distinguished by shell morphology and thus cannot be considered truly cryptic species. The radula is very similar in both species and does not permit species delimitation. A conchological reappraisal of further material similar to C. cerithina allows us to recognize two additional species, which are described as new (C. procera n. sp. from the Coral Sea and Philippines, and C. aurea n. sp. from Tahiti). These results demonstrate that even 'well-known' and seemingly well defined species may be species complexes and that molecular techniques should be routinely applied to confirm specimen identification, especially as part of resource-consuming studies, such as toxinology

COI and RAD-seq trees

MrBayes, BEAST and RAxML trees for COI; RaxML trees for the RAD seq dataset, with the loci shared by at least 30, 40, 50, 60, 70, 80% of the samples

Radseq raw data (demultiplexed fastq)

This file will be a zip file containing the demultiplexed raw reads for each sample. The un-assigned reads (no barcode identified) are not included. They are available on request

Incorporation of deep-sea and small-sized species provides new insights into gastropods phylogeny

The use of phylogeny with uneven or limited taxon sampling may bias our interpretation of organismal evolution, for instance, the origin(s) of the deep-sea animals. The Mollusca is the second most speciose phylum, in which the Gastropoda forms the largest group. However, the currently proposed hypotheses of gastropod phylogeny are mainly based on part of their taxonomic diversity, notably on the large-sized and shallow-water species. In this study, we aimed at correcting this bias by reconstructing the phylogeny with new mitogenomes of deep-sea gastropods including Anatoma sp., Bathysciadiidae sp., Bayerotrochus teramachii, Calliotropis micraulax, Coccocrater sp., Cocculina subcompressa, Lepetodrilus guaymasensis, Peltospira smaragdina, Perotrochus caledonicus, Pseudococculinidae sp., and Shinkailepas briandi. This dataset provided the first reports of the mitogenomes for the Cocculiniformia, three vetigastropod superfamilies: Pleurotomarioidea, Lepetelloidea, and Scissurelloidea, and the neritimorph family Phenacolepadidae. The addition of deep-sea representatives also allowed us to evaluate the evolution of habitat use in gastropods. Our results showed a strongly supported sister-group relationship between the deep-sea lineages Cocculiniformia and Neomphalina. Within the Vetigastropoda, the Pleurotomarioidea was revealed as the sister-group of the remaining vetigastropods. Although this Glade was presently restricted to the deep sea, fossil records showed that it has only recently invaded this habitat, thus suggesting that shallow waters was the ancestral habitat for the Vetigastropoda. The deep-sea Lepetelloidea and Lepetodriloidea formed a well-supported Glade, with the Scissurelloidea sister to it, suggesting an early transition from shallow water to deep sea in this lineage. In addition, the switch between different chemosynthetic habitats was also observed in deep-sea gastropod lineages, notably in Neomphalina and Lepetelloidea. In both cases, the biogenic substrates appeared as the putative ancestral habitat, confirming the previously proposed hypothesis of a wooden-step to deep-sea vents scenario of evolution of habitat use for these taxa

Data from: Delimiting species of marine gastropods (Turridae, Conoidea) using RAD-sequencing in an integrative taxonomy framework

Species delimitation in poorly-known and diverse taxa is usually performed based on monolocus, DNA barcoding-like approaches, while multilocus data are often used to test alternative species hypotheses in well-studied groups. We combined both approaches to delimit species in the Xenuroturris / Iotyrris complex, a group of venomous marine gastropods from the Indo-Pacific. First, COI sequences were analyzed using three methods of species delimitation, ABGD, PTP and GMYC to propose primary species hypotheses (PSH). Second, RAD-seq data were also obtained and an IQ-tree phylogenetic tree produced. We tested the impact of the level of missing data on the robustness of the phylogenetic tree obtained with the RAD-seq data. Alternative species partitions revealed with the COI dataset were also tested using the RAD-seq data and the BFD method. The congruence between the species hypotheses proposed with the mitochondrial gene and the clades in the RAD-seq tree, together with the morphological variability of the shell and the radula and the distribution pattern, was used to turn the PSH into secondary species hypotheses (SSH). Allopatric PSH defined with the COI gene were interpreted to correspond to intraspecific structure. Most of the species are found sympatrically in the Philippines, and only one is confidently identified as a new species and described as Iotyrris conotaxis n. sp. The results obtained demonstrate the efficiency of the combined monolocus/multilocus approach to delimit species

Data from: Delimiting species of marine gastropods (Turridae, Conoidea) using RAD-sequencing in an integrative taxonomy framework

Species delimitation in poorly-known and diverse taxa is usually performed based on monolocus, DNA barcoding-like approaches, while multilocus data are often used to test alternative species hypotheses in well-studied groups. We combined both approaches to delimit species in the Xenuroturris / Iotyrris complex, a group of venomous marine gastropods from the Indo-Pacific. First, COI sequences were analyzed using three methods of species delimitation, ABGD, PTP and GMYC to propose primary species hypotheses (PSH). Second, RAD-seq data were also obtained and an IQ-tree phylogenetic tree produced. We tested the impact of the level of missing data on the robustness of the phylogenetic tree obtained with the RAD-seq data. Alternative species partitions revealed with the COI dataset were also tested using the RAD-seq data and the BFD method. The congruence between the species hypotheses proposed with the mitochondrial gene and the clades in the RAD-seq tree, together with the morphological variability of the shell and the radula and the distribution pattern, was used to turn the PSH into secondary species hypotheses (SSH). Allopatric PSH defined with the COI gene were interpreted to correspond to intraspecific structure. Most of the species are found sympatrically in the Philippines, and only one is confidently identified as a new species and described as Iotyrris conotaxis n. sp. The results obtained demonstrate the efficiency of the combined monolocus/multilocus approach to delimit species