Application of molecular genetics and geometric morphometrics to taxonomy and conservation of cave beetles in central Italy

Integration of molecular genetic techniques and geometric morphometrics represent a valuable tool in the resolution of taxonomic uncertainty and the identification of significant units for conservation. We combined mitochondrial DNA cytochrome c oxidase subunit II gene sequence data and geometric morphometric analysis to examine taxonomic status and identify units for conservation in four species of the hypogean beetle Duvalius (Coleoptera, Trechinae) using mainly museum specimens collected in central Italy. Previous taxonomic studies based on morphological traits described several subspecies often inhabiting geographically distinct caves. Phylogenetic analysis identified two well supported monophyletic lineages and a number of different clades with relatively small genetic differences, suggesting a short divergence time in line with known geological history of the study area. Geometric morphometrics, on the other hand, recovered a high level of distinctiveness among specimens. Both genetic and morphometric analyses did not entirely corroborate former taxonomic nomenclature, suggesting possible rearrangements and the definition of evolutionary significant units. Beetles of the genus Duvalius are protected by regional laws and the majority of taxa considered in this study inhabit caves located outside protected areas. Our study advocates the importance of devoting protection efforts to networks of cave ecosystems rather than single locations or species.     

Norfolk Island Robins are a distinct endangered species: ancient DNA unlocks surprising relationships and phenotypic discordance within the Australo-Pacific Robins

Uncertain taxonomy hinders the effective prioritization of taxa for conservation. This problem is acute for understudied island populations in the southwest Pacific Ocean, which are increasingly threatened by habitat loss, predation and climate change. Here, we offer the first test of taxonomic limits and phylogenetic affinities of the iconic Pacific Robin radiation (Petroica multicolor) in order to prioritize the conservation of its nominotypical subspecies, the endangered Norfolk Island Robin (P. m. multicolor). We integrate phylogenetic analyses of ancient DNA and quantitative measures of plumage and morphometric variation to show that the Norfolk Island Robin should be recognized as a distinct species. Phenotypic and genetic datasets contradict the longstanding treatment of Pacific Robins (including Norfolk Island Robins) and Scarlet Robins (P. boodang) as a single species. Instead, we show that Norfolk Island Robins are deeply divergent from Scarlet Robins and have more genetic similarity to Red-capped Robins (P. goodenovii) than to other Pacific Robins. This finding is unrepresentative of the current taxonomic and conservation status of the Norfolk Island Robin, which we propose should be recognised as an endemic endangered species. Our study clearly shows that in the absence of contemporary tissues, ancient DNA approaches using historical museum specimens can address taxonomic questions that morphological traits are unable to resolve. Further, it highlights the need for similar studies of other threatened Norfolk fauna with uncertain taxonomic status in order to ensure appropriate conservation prioritization.     

Redescription of the western Balkan species Xerocampylaea waldemari and its phylogenetic relationships to other Urticicolini (Gastropoda: Hygromiidae)

The proper identification of species has significant implications for conservation and general knowledge of ecosystem variety. It is especially important for biodiversity hotspots and former Pleistocene refugia, such as the Balkans. In this paper, we evaluate the taxonomic status of the endemic Balkan species Fruticicola waldemari A. J. Wagner, 1912, using both recently collected material and museum specimens. Phylogenetic analyses based on two mitochondrial markers, 16S rRNA and cytochrome c oxidase subunit I, show that this species is closely related to the representatives of Xerocampylaea, including a conchologically similar and partly sympatric species, X. erjaveci. Analyses of shell and genital morphology as well as mitochondrial DNA sequences indicate that X. waldemari and X. erjaveci are separate but closely related species. These species differ in shell morphology (size, umbilicus diameter, microsculpture) as well as genital morphology. Nevertheless, a further study with more comprehensive sampling of both taxa is required to fully understand the complex pattern of genetic and morphological variation observed.     

Genetic and morphological characterization of the freshwater mussel clubshell species complex (Pleurobema clava and Pleurobema oviforme) to inform conservation planning

The shell morphologies of the freshwater mussel species Pleurobema clava (federally endangered) and Pleurobema oviforme (species of concern) are similar, causing considerable taxonomic confusion between the two species over the last 100 years. While P. clava was historically widespread throughout the Ohio River basin and tributaries to the lower Laurentian Great Lakes, P. oviforme was confined to the Tennessee and the upper Cumberland River basins. We used two mitochondrial DNA (mtDNA) genes, 13 novel nuclear DNA microsatellite markers, and shell morphometrics to help resolve this taxonomic confusion. Evidence for a single species was apparent in phylogenetic analyses of each mtDNA gene, revealing monophyletic relationships with minimal differentiation and shared haplotypes. Analyses of microsatellites showed significant genetic structuring, with four main genetic clusters detected, respectively, in the upper Ohio River basin, the lower Ohio River and Great Lakes, and upper Tennessee River basin, and a fourth genetic cluster, which included geographically intermediate populations in the Ohio and Tennessee river basins. While principal components analysis (PCA) of morphometric variables (i.e., length, height, width, and weight) showed significant differences in shell shape, only 3% of the variance in shell shape was explained by nominal species. Using Linear Discriminant and Random Forest (RF) analyses, correct classification rates for the two species'' shell forms were 65.5% and 83.2%, respectively. Random Forest classification rates for some populations were higher; for example, for North Fork Holston (HOLS), it was >90%. While nuclear DNA and shell morphology indicate that the HOLS population is strongly differentiated, perhaps indicative of cryptic biodiversity, we consider the presence of a single widespread species the most likely biological scenario for many of the investigated populations based on our mtDNA dataset. However, additional sampling of P. oviforme populations at nuclear loci is needed to corroborate this finding.     

A new species of Mosiera (Myrtaceae) from the Sierra de Nipe,Cuba

A new species, Mosiera nipensis (Myrtaceae), from the crest of the Sierra de Nipe, Cuba, is described and illustrated. This species is readily distinguished from all other species of Mosiera by two diagnostic characters: four-angled, slightly four-winged young twigs, and calyx lobes that are valvate in the bud. We suspect that this species grows on a serpentine substrate. It is known only from the holotype, a collection made in 1941. An assessment of its conservation status is urgently needed.     

The revenant: rediscovery of Margaritifera homsensis from Orontes drainage with remarks on its taxonomic status and conservation (Bivalvia: Margaritiferidae)

Since Margaritifera marocana (Pallary, 1918) and M. laosensis (Lea, 1863) were rediscovered, M. homsensis (Lea, 1865) remains the only pearl mussel species known solely based on old shell samples from natural history museums. This is also the last pearl mussel species, which is absent in a phylogeny of the family. Here, we aimed to provide an integrative revision of the taxonomic status of M. homsensis from the Orontes Basin. Using a newly collected specimen from the River Karasu, Hatay Province, southern Turkey, five gene partitions were sequenced, the cytochrome c oxidase subunit I (COI), large ribosomal subunit rRNA (16S), large ribosomal subunit rDNA (28S) and its D3 expansion segment (D3), and small ribosomal subunit rDNA (18S). The multi-gene phylogeny indicates that M. homsensis is a sister taxon of M. auricularia, but both these species are closely related to M. marocana by nuclear genes. The main conchological features, i.e., the shell shape, teeth morphology, and mantle attachment scars, as well as Fourier shell shape analysis have not shown principal differences between M. homsensis and M. auricularia. Based on these data, we concluded that M. homsensis is a valid species that is most closely related to M. auricularia. Special conservation efforts for a population of M. homsensis discovered in Turkey, including the formation of a nature reserve, might contribute to the conservation of the species. Finally, an extensive search for surviving populations in Orontes drainage (southern Turkey, Lebanon, and Syria) and the Nahr-el-Kabir River (Lebanon and Syria) remains necessary to develop a transboundary conservation strategy for this unique taxon.     

Molecular evidence for cryptic species in a narrowly endemic western North American springsnail (Pyrgulopsis gilae)

Pyrgulopsis gilae is a small springsnail that is narrowly distributed along the forks of the upper Gila River and currently being managed as a threatened and sensitive species by the State of New Mexico and United States Forest Service, respectively. A previous phylogeographic study of this species based on mitochondrial COI sequences delineated substantial divergence between several populations along the lower and upper reaches of the East Fork Gila River. The present study surveyed COI variation among a larger number of populations across the entire geographic range of P. gilae. Three haplotype groupings were delineated that were congruently resolved as clades by a Bayesian analysis. One of the clades was composed of populations along the lower East Fork and mainstem Gila River and corresponds to P. gilae as originally circumscribed. The other two clades were composed of populations along the Middle Fork and upper East Fork Gila River that were recently referred to P. gilae. These three geographically isolated clades do not share any haplotypes, have significant F_ST values, and are differentiated from each other by 3.9–6.3 % sequence divergence. Based on this evidence we suggest that the clades represent distinct species and should be managed as separate conservation units pending taxonomic revision of P. gilae. This study provides additional evidence that geographically disjunct subunits of Pyrgulopsis species often represent distinct monophyletic lineages that may warrant formal taxonomic recognition, and thus underscores the importance of fine-scale conservation genetics studies of these imperiled organisms.     

New information on body size and cranial display structures of Pterodactylus antiquus, with a revision of the genus

Pterodactylus antiquus has long been thought to have been quite small (~50 cm wingspan) and to have differed from P. longicollum, Ctenochasma, Germanodactylus, and Gnathosaurus in lacking a bony cranial crest, though a soft tissue crest and occipital lappet have been described. This article describes a new specimen of P. antiquus larger than all previously known specimens, which demonstrates that the species exceeded 1 m in wingspan and had a low bony cranial crest. A smaller, incipient crest was identified on the holotype specimen. Additional specimens, including the counterpart of Wellnhofer’s original occipital lappet specimen, provide evidence of the occipital lappet and the soft tissue crest extending upward above the naso-antorbital fenestra and orbit. In order to provide a proper taxonomic context for the findings, the recent synonymization of the species Pterodactylus antiquus and P. kochi on the basis of shared correlation of tooth number and skull length despite perceived differences in dentition and skull, neck, and trunk proportions is reviewed. A measurement error that had made it appear that P. antiquus differed significantly from P. kochi in proportions is documented, and after correction of the measurement error and reevaluation of the dental evidence there are no significant differences between the two nominal species. Thus, the synonymization of P. antiquus and P. kochi was appropriate, and a revised diagnosis is presented. In addition, the species P. longicollum and P. micronyx, which for some years have been viewed as not congeneric with P. antiquus, are placed in a new genus and transferred to Aurorazhdarcho, respectively.     

GENETIC STRUCTURE OF THE WESTERN NORTH AMERICAN AQUATIC GASTROPOD GENUS TAYLORCONCHA AND DESCRIPTION OF A SECOND SPECIES

The Bliss Rapids Snail (Taylorconcha serpenticola) is a threatenedspecies that ranges along a short reach of the middle SnakeRiver in southern Idaho. Additional Taylorconcha populationsof uncertain taxonomic status have recently been discoveredin other portions of the Snake River basin (Owyhee River, lowerSnake River). We investigated the phylogenetic relationshipsand population structure of these snails, together with twooutgroups, using cytochrome c oxidase subunit I (COI) of mitochondrialDNA and the first internal transcribed spacer region betweenthe 18S and 5.8S ribosomal DNA. These data show no sharing ofhaplotypes or genotypes among T. serpenticola and the Owyhee-LowerSnake populations, with both depicted as monophyletic unitswithin the Taylorconcha clade. Both of these datasets and morphologicalevidence suggest that the Owyhee-Lower Snake populations area distinct species, which we describe herein (T. insperata newspecies). Application of an available COI molecular clock suggeststhat Taylorconcha arose in the late Miocene, when ancestralSnake River drainage was impounded in an extensive lacustrinesystem (‘Lake Idaho’) in western Idaho. The shallowpopulation structuring of T. insperata suggests that the lowerSnake River was only recently colonized subsequent to incisionof Hells Canyon, draining of Lake Idaho, and development ofa through-going river in the late Neogene. The absence of significantgenetic structure in T. serpenticola, which is attributed tothe unstable course and flow regime of the middle Snake Riverduring the Quaternary, suggests that this species can be treatedas a single management unit. (Received 14 July 2005; accepted 23 September 2005)     

Updated taxonomic list and conservation status of chondrichthyans from the exclusive economic zone of Venezuela,with first generic and specific records

Using the last taxonomic review of chondrichthyans of the world, we selected the species distributed in the north-western Atlantic Ocean (NWA) and compared it with the available published literature related to the class Chondrichthyes in the Venezuelan exclusive economic zone. We also revised information from worldwide databases such as: FAO (NWA-31 area), GBIF, iSpecies, IUCN and OBIS, as well as available museum collection databases. The taxonomic validity was checked using the Catalogue of Fishes of the California Academy of Sciences and recent references. The past published Venezuelan lists of chondrichthyans combined included nine orders, 30 families and 108 species. The updated list with 12 orders, 36 families and 122 species increased by three new orders, six families, three shark genera, nine shark species (one replacing another species), one chimaera genus, two chimaera species, three batoid genera and six batoid species (two replacing other species). Four holotype specimens (two sharks and two rays) are deposited in Venezuelan Museums. Most of the species have an IUCN conservation status, including four species catalogued as Critically Endangered, six as Endangered and 18 species as Vulnerable. Deep-sea fisheries, scientific exploration and taxonomic/genetic revisions might add future increments to the Venezuelan chondrichthyan list.     

Redescription of Pennella sagitta (Copepoda: Pennellidae) from Histrio histrio (Pisces) in the North-west Atlantic Ocean with a provisional review of the genus Pennella

Pennella sagitta (L.) is redescribed from fresh specimens recovered from Histrio histrio (L.) and from material in the collection of the Smithsonian Institution. A small, delicate parasitic copepod, P. sagitta is shown to be a valid species, found only on fishes of the family Antennariidae. Attempts of earlier workers to synonymize P. diodontis with P. sagitta are rejected, and the distinguishing features of both species are presented. A neotype is proposed from material described herein, due to a lack of the original holotype. A provisional review of the genus Pennella Oken, 1816 is provided, and the taxonomic status of 31 species is discussed. Pennella exocoetus is described from material in museum collections. Seven species, P. balaenoptera, P. diodontis, P. exocoetus, P.filosa, P. instructa, P. makaira and P. sagitta are considered as valid members of the genus. The remaining species are reduced to synonymy with valid species or accorded the status of species inquirendae.