Tropidofusus ypotethys: a new genus and new species of Columbariidae (Mollusca: Gastropoda: Turbinelloidea)

ABSTRACT

The genus Tripidofusus n. gen. is proposed to include Tropidofusus ypotethys n. sp. from bathyal depths off New Zealand, as well as Fulgurofusus aequilonius and Columbarium benthocallis from the abyssal zones of the Bering Sea and Scotia Sea, respectively. Tropidofusus can be distinguished from both Fulgurofusus and Coluzea on the basis of its lower spire, prominent peripheral keel, long, thin siphonal canal, as well as in having a much thinner shell that lacks axial sculpture. The type species, Tropidofusus ypotethys n. sp., differs from its congeners in having a broader peripheral keel, smaller aperture and longer siphonal canal, as well as by inhabiting bathyal rather than abyssal depths. The genus is reviewed and the relationships of Tropidofusus to other supraspecific taxa within Columbariidae are discussed, as are relationships among the families within Turbinelloidea.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:3CA568AD-1B6F-4D4E-9DF7-8377CABB8553     

Phylogenetic relationships between isolated populations of the limestone‐dwelling microsnail Gyliotrachela hungerfordiana (Gastropoda: Vertiginidae)

The vertiginid species Gyliotrachela hungerfordiana, an obligate limestone‐dwelling microsnail, is relatively widespread and is found on a large number of isolated limestone hills in Peninsular Malaysia. To elucidate the pattern of colonization of these hills, we conducted a molecular phylogenetic analysis on G. hungerfordiana subpopulations from 15 separate limestone outcrops. As outgroups, we also included five related Peninsular Malaysian Vertiginidae (Gyliotrachela frequens, Gyliotrachela transitans, Gyliotrachela salpinx, Gyliotrachela depressispira and Paraboysidia tarutao), one population each. A combined analysis of nuclear (internal transcribed spacer 1) and mitochondrial (cytochrome c oxidase 1) sequences showed that (1) G. hungerfordiana is monophyletic; (2) there is a clear geographical pattern in the phylogenetic relationships between G. hungerfordiana populations, with genetic distances increasing with geographic distance; (3) this pattern is disturbed by a few long‐distance (north‐west to south‐east and north to south) colonizations.     

Systematic revision and molecular phylogeny of the land snail genus Fruticocampylaea (Gastropoda: Hygromiidae) from the Caucasus region

This paper presents a systematic revision and a molecular phylogenetic analysis of the Caucasian land snail genus Fruticocampylaea. The genus is newly delimited based on the reduction of the cavities adjoining the seminal duct in the penial papilla. Shell and genitalia of all five species (F. narzanensis, F. kobensis, F. tushetica sp. nov., F. christophori, F. daghestana) are described and figures provided. All synonyms and all locality records are listed. Maximum likelihood and Bayesian analyses of mitochondrial and nuclear DNA sequences (fragments of cox1, 16S rDNA, ITS2 and 28S rDNA) confirm the monophyly of Fruticocampylaea. The reduction of the dart apparatus and the conical plug, via which the dart apparatus inserts into the vagina, as well as the molecular phylogenetic analyses, suggests a sister group relationship between Fruticocampylaea and Circassina (without Abchasohela). Furthermore, the molecular phylogenetic analyses indicate that the Fruticocampylaea species originated in a rapid radiation. The uplift of the Greater Caucasus in the Late Miocene or Pliocene or climatic changes at the end of the Pliocene or in the early Pleistocene may have caused the radiation of Fruticocampylaea. Low intraspecific variability can be explained by population bottlenecks during Pleistocene glacial periods followed by postglacial population increase.

http://zoobank.org/urn:lsid:zoobank.org:pub:AB15158D-21A3-4945-8D49-F7DE8E406E2B     

Systematic revision of the formerly monotypic genus Tanganikallabes (Siluriformes: Clariidae)

The monotypic genus Tanganikallabes, endemic to Lake Tanganyika, is a poorly known member of the family Clariidae. Examination of 142 specimens housed in museum collections has revealed the presence of at least two additional species in this genus. Tanganikallabes alboperca sp. nov. is distinguished from all congeners by the length of its pelvic fins, the presence of a depigmented vertical bar on the opercular margin, and a combination of additional morphometric (pectoral spine length, preanal length, body depth at anus) and meristic (dorsal and anal fin ray counts) characters. Tanganikallabes stewarti sp. nov. is distinguished from other Tanganikallabes species by having a relatively shorter, incomplete lateral line, and shallow body depth at the anus, as well as shorter prepelvic and preanal lengths, and a longer anal fin with a higher number of fin rays. Several morphological characters, as well as genetic data from cytochrome b (mitochondrial DNA) and 18S–ITS1–5.8S–ITS2–28S (ribosomal DNA), indicate that Tanganikallabes constitutes a monophyletic group within the Clariidae and support the recognition of additional species diversity. The monophyly of Tanganikallabes, coupled with the geographical isolation of this group to a single lake satisfy the requirements for its classification as a true species flock, the latest to be described from Lake Tanganyika. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 121–142.     

Conchometrics, systematics and distribution of Melanopsis (Mollusca: Gastropoda) in the Levant

In this conchometric study, the systematics and distribution of the freshwater gastropod Melanopsis in the Levant are described. Of the ten species found, three are widespread, two have narrow distributions and five are known only from their type locality. Five smooth‐shelled species are recognized (buccinoidea, ammonis, dircaena, khabourensis and meiostoma). Within M. buccinoidea, Jordan Valley populations may belong to a separate subspecies. M. ammonis is clearly differentiated from buccinoidea of the nearby Jordan Valley, but less so from buccinoidea of more distant sites; differences between ammonis and meiostoma are significant but not diagnostic. Five species have ribbed shells. Within costata, four subspecies are recognized (in the northern Orontes, upper Jordan, Sea of Galilee, and in southernmost parts of the Levant). Throughout the Levant, M. buccinoidea frequently hybridizes with M. costata and fossil evidence suggests that these species have been hybridizing for the last 1.5 Myr. M. saulcyi differs from M. costata in its narrower shell and shorter, bumpier ribs and frequently hybridizes with M. buccinoidea throughout the Levant. Specimens from Homs differ from those of the Jordan Valley in their higher figurativity index, fewer ribs and lower rib density. M. germaini differs from M. costata in its more numerous ribs, M. pachya in its shorter ribs, and M. infracincta in its bumpy shell in which each rib has huge tubercles, with a pronounced ridge flanking the columella. Our conclusion that there are ten species in the Levant differs from previous studies that suggested only two subspecies of one species (or superspecies). This difference could stem from (1) our use of nonstandard as well as standard conchometrics, (2) a reappraisal of the importance of the shell vs. the radula in intrageneric systematics, and (3) differences of opinion on the subspecies concept. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 144 , 229?260.     

Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa

The monophyly of the land snail family Camaenidae has been in doubt due to a disjunct bihemispheric distributional pattern and to the lack of morphological synapomorphies. A cladistic analysis is presented using an ingroup composed of representatives of the three subfamilies distributed in Australia and 52 other species with American distribution. Bradybaenidae, Helicidae and Helminthoglyptidae were used as outgroups. Fifty morphological characters were treated as unordered and analysed using Pee-Wee ver. 2.9, a program for parsimony analysis using implied weights. The results of the analysis support Camaenidae as a monophyletic family (synapomorphies: oval genital orifice, absence of penial sheath). Two of the three Australasian subfamilies, Sinumeloninae and Camaeninae, are monophyletic in the strict consensus tree. The American taxa are classified in eight genera and arranged into two main clades. Caracolus is proposed as the sister group of the American Continental Camaenidae. The genus Solaropsis , previously excluded from this family by different authors, is reassigned to Camaenidae. Shell characters proved to be phylogenetically informative in defining Pleurodonte , Caracolus , Solaropsis , Isomeria and Labyrinthus . © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 138, 449–476.     

Phylogeography of Plectostylus Beck, 1837 (Gastropoda: Stylommatophora: Orthalicoidea): Origin and isolation of the Fray Jorge forest relicts in northern Chile

Among the questions surrounding the biogeographical history of the Chilean biota, none has gathered more interest than the origin of the Fray Jorge (FJ) forest relict and its biota. Inserted in a semi‐desert area, this forest enclave exists due to the existence of a very particular microclimate in this region. The age of the disjunction and the historical relationship between the FJ biota with the remaining components of South America are explained by two distinct, competing hypotheses: the first suggests that it would have become isolated during the climatic changes of the Paleogene/Neogene, while the second suggests that the isolation is a product of Quaternary glaciations. To discriminate between these competing hypotheses, we used DNA sequence phylogeny methods and molecular genetic dating to the study of a genus of land snails (Plectostylus) that occurs in the FJ relict and throughout Chile. The phylogeny shows a clear distinction between forest and arid clades, and each of these clades is formed by many geographically circumscribed populations. The FJ fragment snails form a clade that is sister to all other forest clades. The separation between the Fray Jorge clade and the other forest clades dates back to the Paleogene/Neogene. Our data suggest that the FJ forest is a relict from the forests that occupied that landscape during the Paleogene/Neogene and retreated due to the aridification of the region. We also observe that the current taxonomy of the Plectostylus genus must be re‐evaluated.     

Species limits and phylogenetic relationships of red‐finned cryptic species of the seasonal killifish genus Hypsolebias from the Brazilian semi‐arid Caatinga (Teleostei: Cyprinodontiformes: Rivulidae)

Members of the Hypsolebias antenori species group comprise a diverse clade of morphologically similar seasonal killifishes occurring in a vast region of the semi‐arid savannah of northeastern Brazil. The present paper focuses on an assemblage of three allopatric cryptic species (H. antenori from isolated coastal river drainages, Hypsolebias igneus from the São Francisco River basin and Hypsolebias coamazonicus sp. nov. from the Parnaíba River basin) sharing almost identical colour patterns, including the presence of an orangish red anal fin in males, thus herein named as the red‐finned assemblage. A tree‐based approach using mt‐DNA (cytochrome b) supports delimitation of all three species, but indicates that the red‐finned assemblage is paraphyletic – H. igneus and H. coamazonicus are closely related to Hypsolebias nudiorbitatus, whereas H. antenori is the sister group to a clade comprising all 13 species of the H. antenori group included in the analysis. Morphological characters are useful to diagnose species, but are not informative for most clades highly supported by molecular data. H. coamazonicus is distinguished from all other congeners by the possession of a dark grey or black stripe on the dorsal fin in males. The basal position of H. antenori is related to uplift episodes involving the Araripe‐Borborema plateau during the Miocene, which isolated the coastal area inhabited by H. antenori from the remaining areas of the Caatinga. The sister group relationship between H. igneus and H. coamazonicus is attributed to a past connection between the São Francisco and Paranaíba River until the Tertiary.     

A pre‐Miocene Irano‐Turanian cradle: Origin and diversification of the species‐rich monocot genus Gagea (Liliaceae)

The Irano‐Turanian (IT) floristic region is considered an important center of origin for many taxa. However, there is a lack of studies dealing with typical IT genera that also occur in neighboring areas. The species‐rich monocot genus Gagea Salisb. shows a center of diversity in IT region and a distribution in adjacent regions, therefore representing a good study object to investigate spatial and temporal relationships among IT region and its neighboring areas (East Asia, Euro‐Siberia, Himalaya, and Mediterranean). We aimed at (a) testing the origin of the genus and of its major lineages in the IT region, (b) reconstructing divergence times, and (c) reconstructing colonization events. To address these problems, sequences of the ribosomal DNA internal transcribed spacer (ITS) region of 418 individuals and chloroplast intergenic spacers sequences (psbA‐trnH, trnL‐trnF) of 497 individuals, representing 116 species from all sections of the genus and nearly its entire distribution area were analyzed. Divergence times were estimated under a random molecular clock based on nrITS phylogeny, which was the most complete data set regarding the representation of species and distribution areas. Ancestral distribution ranges were estimated for the nrITS data set as well as for a combined data set, revealing that Gagea most likely originated in southwestern Asia. This genus first diversified there starting in the Early Miocene. In the Middle Miocene, Gagea migrated to the Mediterranean and to East Asia, while migration into Euro‐Siberia took place in the Late Miocene. During the Pleistocene, the Arctic was colonized and Gagea serotina, the most widespread species, reached North America. The Mediterranean basin was colonized multiple times from southwestern Asia or Euro‐Siberia. Most of the currently existing species originated during the last 3 Ma.     

One Beringian genus less: A re‐assesment of Pacifimyxas Kruglov & Starobogatov, 1985 (Mollusca: Gastropoda: Lymnaeidae) questions the current estimates of Beringian biodiversity

The taxonomic position of three nominal species of lymnaeid snails placed by Kruglov & Starobogatov (1993) into the subgenus Lymnaea (Pacifimyxas) Kruglov & Starobogatov, 1985, has been re‐assessed based on a molecular genetic study of topotypic specimens and an examination of the type series and other materials available. It has been shown that the two species, Lymnaea (Pacifimyxas) magadanensis Kruglov & Starobogatov, 1985 and Lymnaea (Pacifimyxas) streletzkajae Kruglov & Starobogatov, 1985, are identical with the species Kamtschaticana kamtschatica (Middendorff, 1850) and must be treated as its junior synonyms. Hence, Pacifimyxas becomes a junior synonym of Kamtschaticana Kruglov & Starobogatov, 1984. The taxonomic identity of the third species of Pacifimyxas, Lymnaea (Pacifimyxas) perpolita, remains obscure, and this species is considered here as taxon inquirendum. Two other nominal species, Lymnaea aberrans (Westerlund, 1897) and Lymnaea middendorffi (W. Dybowski, 1904), have been synonymized with K. kamtschatica based on morphological and geographical evidence. The lectotype of Limnaea peregra var. middendorffi is designated. The actual level of species richness in the Beringian freshwater malacofauna may be 20–25% lower than it was determined on the basis of the traditional system. Some implications of this outcome for the biogeography of the Beringian freshwater fauna are discussed.     

A molecular test of Huxley's line: Cyrtandra (Gesneriaceae) in Borneo and the Philippines

A biogeographic and phylogenetic study of Cyrtandra (Gesneriaceae) in the Sundaland region (Borneo and Peninsular Malaysia) and the Philippines using nuclear ribosomal (ITS) DNA sequence data reveals a major division between the Cyrtandra floras of Sundaland and the Philippines. Palawan, the most westerly of the Philippine islands, emerges as an area of mixing between these two. The Bornean element in the Cyrtandra flora of Palawan (two species in our sample) appears to result from recent (i.e. Pleistocene) dispersal from Borneo. The remaining seven species sampled from Palawan are most closely related to those from elsewhere in the Philippines. However, the Palawan clade is sister to the other Philippine taxa, suggesting an ancient (possibly Pliocene) vicariance event. Huxley's line–a zoogeographic boundary placing Palawan and Borneo together–receives some support from this study as there is evidence of recent dispersal of Bornean flora into Palawan. However, in terms of more ancient biogeographic patterning of the region, Palawan has stronger links with the other Philippine islands.     

‘After Africa’: the evolutionary history and systematics of the genus Charaxes Ochsenheimer (Lepidoptera: Nymphalidae) in the Indo‐Pacific region

The predominantly Afrotropical genus Charaxes is represented by 31 known species outside of Africa (excluding subgenus Polyura Billberg). We explored the biogeographic history of the genus using every known non‐African species, with several African species as outgroup taxa. A phylogenetic hypothesis is proposed, based on molecular characters of the mitochondrial genes cytochrome oxidase subunit I (COI) and NADH dehydrogenase 5 (ND5), and the nuclear wingless gene. Phylogenetic analyses based on maximum parsimony and Bayesian inference of the combined dataset implies that the Indo‐Pacific Charaxes form a monophyletic assemblage, with the exception of Charaxes solon Fabricius. Eight major lineages are recognized in the Indo‐Pacific, here designated the solon (+African), elwesi, harmodius, amycus, mars, eurialus, latona, nitebis, and bernardus clades. Species group relationships are concordant with morphology and, based on the phylogeny, we present the first systematic appraisal and classification of all non‐African species. A biogeographical analysis reveals that, after the genus originated in Africa, the evolutionary history of Charaxes in the Indo‐Pacific, in particular Wallacea, may be correlated with the inferred geological and climatic history of the region. We propose that Wallacea was the area of origin of all Charaxes (excluding C. solon) occurring to the east of Wallace's [1863] Line. The earliest Indo‐Pacific lineages appear to have diverged subsequent to the initial fragmentation of a palaeo‐continent approximately 13 million years ago. Further diversification in Indo‐Pacific Charaxes appears primarily related to climatic changes during the Pliocene and possibly as recently as the Pleistocene. Although both dispersal and vicariance have played important roles in the evolution of the genus within the region, the latter has been particularly responsible for diversification of Charaxes in Wallacea. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 457–481.     

Towards a monophyletic genus Albinaria (Gastropoda, Pulmonata): the first molecular study into the phylogenetic position of eastern Albinaria species

Recent molecular phylogenetic studies of the terrestrial snail genus Albinaria have caused a radical reassessment of its taxonomy. These studies, however, were limited to western species. This paper examines mitochondrial 12S sequences and nuclear ITS1 & 2 sequences of both eastern and western species, and demonstrates that Albinaria, in its most recent definition, is not monophyletic. Both molecular datasets place ' Albinaria ' hedenborgi from Lebanon in a well-supported clade with species of the genus Cristataria , distributed south-east of the vicariant range of Albinaria . The remaining species from Cyprus, Turkey and Greece constitute a well-supported monophyletic group. These two clades form geographical clusters, whereas Albinaria in the current definition (including ' A. '  hedenborgi ) has a disjunct distribution. ' A.' hedenborgi should therefore be classified with Cristataria , together with the morphologically similar and geographically close ' A. '  nadimi .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 531−542.     

New insights into and limitations of the molecular phylogeny in the taxon-rich land snail genus Montenegrina (Mollusca: Gastropoda: Clausiliidae)

Rock-dwelling gastropods are usually patchily distributed in limestone habitats, presumably have low active and passive dispersal ability and often represent narrow-ranged endemic taxa. Their current taxonomy is predominantly shell morphology based, and it remains unknown whether the morphologically differentiated and geographically separated populations represent phylogenetic clades. In this study, we analysed the hyperdiverse, terrestrial door snail genus Montenegrina. Based on the current taxonomy defined by shell morphology, it contains 29 species and 106 subspecies distributed in the Balkan region. The constructed phylogenetic tree using three mitochondrial markers was used to test whether it agrees with the current taxonomy. In this comprehensive tree, about half of the species and subspecies are monophyletic. Some of the paraphylies could be reasonably resolved by taxonomic changes; that is, some subspecies should be reassigned or raised to species level. Other incongruencies probably arose due to introgression even between distant clades. The histone genes turned out to be unsuitable for elucidating the phylogeny of Montenegrina. In the species-delimitation tests, considerably more molecular operational taxonomic units were delimited than the number of presently described species. The present data indicate that (a) shell morphology-based taxonomy and taxon recognition can be problematic in such a large and morphologically highly variable genus; (b) the potential error due to incomplete sampling presents a problem in a genus as variable as Montenegrina; (c) multi-locus analyses should be conducted to arrive at a better basis for species delimitation; and (d) integrative approaches including genetic as well as morphological/anatomical data from a comprehensive geographic sample are necessary.     

Mimetic colour pattern evolution in the highly polymorphic Bombus trifasciatus (Hymenoptera: Apidae) species complex and its comimics

Müllerian mimetic systems have uncovered some of the dynamic processes by which natural selection can drive the radiation of convergent and divergent phenotypes. We examined evolution involving Müllerian mimicry in bumble bees by documenting the distribution and evolution of colour patterns amongst three colour‐polymorphic lineages –Bombus trifasciatus Smith, Bombus haemorrhoidalis Smith, and Bombus breviceps Smith – that mimic each other across ～14 colour groups in South‐East Asia. Using mitochondrial DNA sequence data, we estimated relationships within each lineage to infer the processes that gave rise to the colour diversity and develop hypotheses on species recognition. We expanded on our assessment of species delineation in the B. trifasciatus lineage using three nuclear gene fragments and morphometrics. Comparison of colour patterns amongst georeferenced specimens showed considerable variation in the degree and geographical range of mimicry amongst mimicry groups. Phylogenetic estimates show high rates of colour pattern evolution, with colour variation often exceeding variation within the fast‐evolving mitochondrial genes. The molecular data, and to some degree the morphometric data, support unique histories for several taxa recognized previously within the B. trifasciatus lineage, which may include several species. Early vicariant events within the B. trifasciatus lineage are likely to have occurred ～2.2 Mya in the mountains of south‐west China. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 805–826.     

Speciation in sympatric species of land snails from the genus Trochulus (Gastropoda,Hygromiidae)

The identification and designation of land snail species in the genus Trochulus on the basis of shell characteristics are problematic because of their great phenotypic plasticity. Some genetic analyses have proved inconclusive, with much variation within populations and apparent gene flow among them. We examined this issue by morphometric and molecular approaches on the morphologically similar species T. coelomphala, T. hispidus and T. striolatus, co‐occurring in the Alpenvorland of Germany. While these species differed in shell and reproductive system morphology, there were forms that turned out intermediate in shell characters between T. coelomphala and T. hispidus but had genital morphology similar to T. coelomphala. Phylogenetic analysis, however, showed that these forms clustered neither with T. coelomphala nor T. hispidus but are sister to T. striolatus from the same region, which suggests that they evolved by way of sympatric speciation. Further, these analyses suggest that T. coelomphala diverged within T. hispidus; a crossing experiment indicated that they were interfertile. Expanding the study to include all available Trochulus sequences enabled us to infer evolutionary relationships between them and showed that T. hispidus is polyphyletic. Some Trochulus samples of one nominal species were grouped within others. The combination of phenotypic plasticity and possible mitochondrial DNA introgression illustrates the complex nature of evolutionary processes and the need for caution in the application of traditional taxonomic practice.     

Distribution of land snails (Mollusca, Gastropoda, Pulmonata) on the island of Gran Canaria (Canary Islands) in relation to protected natural areas

The oceanic island of Gran Canaria, part of the Macaronesian Archipelagos, is highly deteriorated, a situation which has had negative repercussions for endemic species. A recent law, however, established 32 Protected Natural Areas in an attempt to remedy the problem. In the present work we show the distribution of common (non-endemic) land snails on the island. The snails were largely introduced by man over the past five centuries. A comparison between the distribution of the endemic land snails and the protected areas shows the latter to be generally adequate. We also suggest some modifications to the law in two Areas and the addition to the list of two further Areas so as to guarantee protection of several endemic species currently under threat (according to the criteria of the IUCN): 2 critically endangered, Hemicycla saulcyi saulcyi and Napaeus isletae, 2 vulnerable, Theba arinagae and Obelus despreauxii, and 1 lower risk, Hemicycla berkeleyi.     

Taxonomic revision of the genus Cutleria proposing a new genus Mutimo to accommodate M. cylindricus (Cutleriaceae,Phaeophyceae)

Molecular phylogenetic analyses of representative Cutleria species using mitochondrial cox3, chloroplast psaA, psbA and rbcL gene sequences showed that C. cylindrica Okamura was not included in the clade composed of other Cutleria species including the generitype C. multifida (Turner) Greville and the related taxon Zanardinia typus (Nardo) P.C. Silva. Instead, C. cylindrica was sister to the clade composed of the two genera excluding C. cylindrica. Cutleria spp. have heteromophic life histories and their gametophytes are rather diverse in gross morphology, from compressed or cylindrical‐branched to fan‐shaped, whereas the sporophytes are rather similar. In contrast, the monotypic species Z. typus has an isomorphic life history and resembles fan‐shaped Cutleria in morphology. Morphological comparisons of these taxa revealed that C. cylindrica is morphologically distinct from other Cutleria spp. and Z. typus in having cylindrical gametophytes with multiseriate trichothallic filaments instead of uniseriate filaments (hairs) characteristic of Cutleriales (or Cutleriaceae, Tilopteridales), and in lacking rhizoidal filaments in the crustose sporophytes. Therefore, based on the molecular and morphological data, the establishment of a new genus Mutimo to accommodate C. cylindrica, and the new combination of M. cylindricus, is proposed.     

Phylogeography of the whelk genus Cominella (Gastropoda: Buccinidae) suggests long‐distance counter‐current dispersal of a direct developer

The gastropod genus Cominella Gray, 1850 consists of approximately 20 species that inhabit a wide range of marine environments in New Zealand and Australia, including its external territory, the geographically isolated Norfolk Island. This distribution is puzzling, however, with apparently closely‐related species occurring either side of the Tasman Sea, even though all species are considered to have limited dispersal abilities. To determine how Cominella attained its current distribution, we derived a dated molecular phylogeny, which revealed a clade comprising all the Australian and Norfolk Island species nested within four clades of solely New Zealand species. This Australian clade diverged well after the vicariant separation of New Zealand from Australia, and implies two long‐distance dispersal events: a counter‐current movement across the Tasman Sea from New Zealand to Australia, occurring at the origination of the clade, followed by the colonization of Norfolk Island. The biology of Cominella suggests that the most likely method of long‐distance dispersal is rafting as egg capsules. Our robust phylogeny also means that the current Cominella classification requires revision. We propose that our clades be recognized as subgenera: Cominella (s.s.), Cominista, Josepha, Cominula, and Eucominia, with each subgenus comprising only of New Zealand or Australian species. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 315–332.