Dispersal and gene flow in free-living marine nematodes

Dispersal and gene flow determine connectivity among populations, and can be studied through population genetics and phylogeography. We here review the results of such a framework for free-living marine nematodes. Although field experiments have illustrated substantial dispersal in nematodes at ecological time scales, analysis of the genetic diversity illustrated the importance of priority effects, founder effects and genetic bottlenecks for population structuring between patches <1 km apart. In contrast, only little genetic structuring was observed within an estuary (<50 km), indicating that these small scale fluctuations in genetic differentiation are stabilized over deeper time scales through extensive gene flow. Interestingly, nematode species with contrasting life histories (extreme colonizers vs persisters) or with different habitat preferences (algae vs sediment) show similar, low genetic structuring. Finally, historical events have shaped the genetic pattern of marine nematodes and show that gene flow is restricted at large geographical scales. We also discuss the presence of substantial cryptic diversity in marine nematodes, and end with highlighting future important steps to further unravel nematode evolution and diversity

First report of the exotic blue land planarian, Caenoplana coerulea (Platyhelminthes, Geoplanidae), on Menorca (Balearic Islands, Spain)

In April 2009 two specimens of a terrestrial flatworm were collected from under a rock in an orchard at Ciutadella de Menorca on the easternmost Balearic island of Menorca (Spain). Their external morphology suggested that both specimens belonged to the invasive blue planarian Caenoplana coerulea, a species which is native to eastern Australia. Sequence data of a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) and of the entire 18S ribosomal RNA confirm its identification. This is one of the first records of the species in Europe where it has only been found in one locality in the United Kingdom, France and NE Spain

Review of the genus Endothyrella Zilch, 1960 with description of five new species (Gastropoda, Pulmonata, Plectopylidae)

All known taxa of the genus Endothyrella Zilch, 1960 (family Plectopylidae) are reviewed. Altogether 23 Endothyrella species are recognized. All species are illustrated and whenever possible, photographs of the available type specimens are provided. Five new species are described: E. angulata Budha & Páll-Gergely, sp. n., E. dolakhaensis Budha & Páll-Gergely, sp. n. and E. nepalica Budha & Páll-Gergely, sp. n. from Nepal, E. robustistriata Páll-Gergely, sp. n. from the Naga Hills, India, and E. inexpectata Páll-Gergely, sp. n. from Sichuan, China. Helix (Plectopylis) munipurensis Godwin-Austen, 1875 is synonymized with Helix (Plectopylis) serica Godwin-Austen, 1875, and Plectopylis (Endothyra) gregorsoni Gude, 1915 is synonymized with Helix (Plectopylis) macromphalus W. Blanford, 1870. Plectopylis plectostoma var. exerta Gude, 1901 is a synonym of Plectopylis plectostoma var. tricarinata Gude, 1896, which is a species in its own right. Five species of the genus Chersaecia viz. Plectopylis (Chersaecia) bedfordi Gude, 1915, Helix (Plectopylis) brahma Godwin-Austen, 1879, Helix (Plectopylis) Oglei Godwin-Austen, 1879, Helix (Plectopylis) serica Godwin-Austen, 1875, and Plectopylis (Endothyra) williamsoni Gude, 1915 are moved to Endothyrella. The holotype of Plectopylis hanleyi Godwin-Austen, 1879 seems to be lost; therefore, P. hanleyi is considered to be a nomen dubium.ArticleZOOKEYS. (529):1-70 (2015)journal articl

Moluscos terrestres da Ilha de Santa Maria. Lista preliminar.

V Expedição Científica do Departamento de Biologia – Santa Maria e Formigas 1990.A ilha de Santa Maria tem, desde os primórdios dos estudos malacológicos do Arquipélago, chamado a atenção dos estudiosos pela originalidade da sua formação geológica e da sua malacofauna (Morelet, 1860). A pequenez dos seus 97 km2 é compensada pela sua avançada idade geológica, quando comparada com a das restantes ilhas açorianas. Se bem que a hipótese de Zbyszewski & Ferreira (1961), que apontava para o vindoboniano (ca. 12 Ma) a origem dos calcários fossilíferos existentes na ilha, tenha vindo a ser corrigida para datas muito mais recentes (ca. 3.5-4 Ma), tendo-se estimado as lavas mais antigas em cerca de 6 Ma (Feraud et al., 1984), Santa Maria continua a ser a relíquia geológica do Arquipélago. É, provavelmente, esta ancestralidade em relação às outras ilhas que justifica a elevada taxa de endemismos que a caracteriza (ca. 19% quando comparada com ca. 8% de São Miguel, numa análise preliminar de dados em preparação para publicação)

Moluscos terrestres das Flores. Lista preliminar.

IV Expedição Científica do Departamento de Biologia – Flores 1989.A ilha das Flores, a mais ocidental e geologicamente uma das mais antigas do Arquipélago, regista uma das mais baixas taxas de endemismos na malacofauna terrestre Açoriana. Até ao presente, não sem alguma discórdia, apenas duas espécies, Balea nitida Mousson, 1858 e Phenacolimax (Insulivitrina) finitima (Morelet, 1860), são geralmente consideradas endémicas naquela ilha. Simroth (1889, fide Backhuys, 1975) sinonimizou com Phenacolimax (I.) pelagica (Morelet, 1860) todas as outras espécies daquele género descritas por este autor. Nobre (1924) não reconheceu a espécie descrita por Mousson, que sinonimizou com a europeia Balea perversa (L., 1758), e pôs reservas quanto às sete espécies de Phenacolimax stabile descritas por Morelet, admitindo também que um estudo mais aprofundado poderia vir a reduzir o número de espécies daquele género; Hoffmann (1929, fide Backhuys, 1975) reduziu-as a três. Riedel (1964), que fez a revisão dos Zonitidae açorianos baseado em material recolhido por P. Brinck e E. Dahl em 1957, não teve acesso a exemplares das Flores. Backhuys (1975) seleccionou as Flores como localidade tipo para Balea nitida Mousson, mencionou uma possível nova espécie de Actinella Lowe e, de modo preliminar e sem justificação descritiva, considerou P. (I.) finitima como parte daquilo que aquele autor chama 'complexo Phenacolimax (I.) brumalis (Morelet)'. O material recolhido na Expedição FLORES/89 veio revelar uma taxa de endemismos mais elevada, aparentemente mais conforme com a idade e o isolamento da ilha. Assim: (i) o subgénero Drouetia Gude, numa análise preliminar, deverá contar com duas, provavelmente três espécies novas; este subgénero, endêmico nos Açores, é objecto de estudo por um dos autores (AMFM) e terá apropriado tratamento em tempo oportuno; (ii) observação da morfologia externa do animal e da concha mostrou que poderá existir mais uma espécie de Phenacolimax para além daquela dada por Morelet para as Flores; o estudo desta espécie fará parte de um projecto de trabalho de um dos autores (CPB), a iniciar-se brevemente; (iii) aparentemente confirmam-se as suspeitas de Backhuys (1975) quanto ao género Actinella nas Flores; o material recolhido constituirá, em breve, objecto de revisão por um dos autores (RTC); (iv) finalmente, a descrição de uma nova espécie de Leptaxis Lowe foi levada a cabo por dois dos autores (AMFM e TB) e está em vias de publicação. Poderá, deste modo e em breve ser o número de endemismos das Flores aumentado significativamente, o que virá a modificar o cenário zoogeográfico do Arquipélago

Habitat suitability modelling of four terrestrial slug species in the Iberian Peninsula (Arionidae: Geomalacus species)

Ecological niche modelling (ENM) determines habitat suitability of species by relating records of occurrence to environmental variables. Here, we investigated habitat suitability of four terrestrial slugs of the genus Geomalacus from the Iberian Peninsula using ENM. The potential distribution of these species was estimated using maximum entropy modelling. For this we used published presence records, together with observations from our fieldwork, and 10 layers of environmental variables in a crossvalidation design using ` minimum predicted area' as a measure of success. For each species, the models predicted distributions with high accuracy, while restricting predictions to minimum areas. Precipitation, and to a lesser extent temperature, were the most important variables to predict the distributions of the four species. We then compared the predicted distributions with the currently known distributions. For G. anguiformis and G. maculosus the predicted distributions included the known distributions, but also nearby mountain areas where these species have not previously been found. For G. malagensis and G. oliveirae the models predicted much wider distributions. Subsequent dedicated fieldwork could not confirm the presence of G. oliveirae in the newly predicted areas. Conversely, G. malagensis was found at five new and distant localities, including areas in Portugal where the species has not previously been recorded.Fundacao para a Ciencia e Tecnologia (Portugal) [SFRH/BD/30024/2006, PTDC/BIA-BDE/74349/2006]; BELSPO projects [MO/36/017]; IUAP-SPEEDYinfo:eu-repo/semantics/publishedVersio

Population genetics of Tapes decussatus in the Lagoa de Santo Cristo, São Jorge : Preliminary results.

VIII Expedição Científica do Departamento de Biologia – Ilha do Faial - 1993.The Lagoa de Santo Cristo in São Jorge is the only place in the Azores where the venerid bivalve Tapes decussatus (Linnaeus, 1758) forms a well established and stable population. This is in itself already a remarkable situation, for the geographically nearest populations of this species live, as far as we know, along the Atlantic coasts of Portugal and Morocco. Thus the Azorean stock is separated from its neighbors by an oceanic gap of more than 1500Km. Another important characteristic of the Azorean Tapes population is the constant human pressure under which it survives. Indeed, Tapes is considered as a popular food item for human consumption and it has therefore been intensively fished in the Lagoa de Santo Cristo, even though in the last years several measures have been taken to regulate the Tapes fisheries

A century of coping with environmental and ecological changes via compensatory biomineralization in mussels

Accurate biological models are critical to predict biotic responses to climate change and human‐caused disturbances. Current understanding of organismal responses to change stems from studies over relatively short timescales. However, most projections lack long‐term observations incorporating the potential for transgenerational phenotypic plasticity and genetic adaption, the keys to resistance. Here, we describe unexpected temporal compensatory responses in biomineralization as a mechanism for resistance to altered environmental conditions and predation impacts in a calcifying foundation species. We evaluated exceptional archival specimens of the blue mussel Mytilus edulis collected regularly between 1904 and 2016 along 15 km of Belgian coastline, along with records of key environmental descriptors and predators. Contrary to global‐scale predictions, shell production increased over the last century, highlighting a protective capacity of mussels for qualitative and quantitative trade‐offs in biomineralization as compensatory responses to altered environments. We also demonstrated the role of changes in predator communities in stimulating unanticipated biological trends that run contrary to experimental predictive models under future climate scenarios. Analysis of archival records has a key role for anticipating emergent impacts of climate change

A new jewel-like species of the pill-millipede genus Sphaerobelum Verhoeff, 1924 (Diplopoda, Sphaerotheriida, Zephroniidae) from Thailand

A new species of the giant pill millipede genus Sphaerobelum is described: Sphaerobelum turcosa sp. nov. from the northeastern part of Thailand. Species delimitation is based on morphological characters and COI sequence data. The new species can be clearly discriminated from congeners by its greenish-blue body color, the face mask-like appearance of the thoracic and anal shields jointly when rolled up, and the combination of the following four characters: (1) the coxa of the second leg laterally with a sharp and long process, (2) the tarsi of legs 4–21 with 6–7 ventral spines, (3) the anterior telopods consisting of four conspicuous telopoditomeres, and (4) the immovable, slender (not strongly humped) and distally curved finger of the posterior telopods without a membranous spot. The interspecific COI sequence divergence between the new species and other Sphaerobelum species ranges from 17% to 23% (mean 20%). The intergeneric COI sequence divergence between the new species and Zephronia species ranges from 18% to 21% (mean 20%). The relationships among Sphaerobelum and Zephronia species based on the COI sequence data were not resolved in this study. Sphaerobelum turcosa sp. nov. is restricted to limestone habitat in Loei province and is probably endemic for the Thai fauna

Morphological and DNA analyses reveal cryptic diversity in Anentome wykoffi (Brandt, 1974) (Gastropoda: Nassariidae), with descriptions of two new species from Thailand

The assassin snail genus Anentome is widely distributed in South East Asia. In Thailand, the genus comprises at least six species, one of which is Anentome wykoffi, a species that may act as an intermediate host of parasitic trematodes. Recent fieldwork has shown that A. wykoffi is far more common and widespread in Thailand than has been assumed, yet the taxonomy remains poorly known. Therefore, this study explores morphological and DNA sequence (COI and 28S rRNA) variation in A. wykoffi to verify and finetune the taxonomic interpretation of this species. To this end, 12 populations of A. wykoffi were sampled in Thailand. This survey allowed us to preliminarily distinguish three putatively cryptic morphotypes. Shell shape measurements and geometric morphometric analyses revealed significant differences between these morphotypes, whereas SEM observations of the shell sculpture and radula confirmed the consistent separation of the three morphotypes. Finally, a combined phylogenetic and species delimitation analysis of COI and 28S rRNA sequence data showed that the three morphotypes represent three well-supported clades, one of which is sister group to A. cambojiensis. As such, the three morphotypes as defined by (1) the presence or absence of a carinated shoulder, (2) the number of spiral lines on the spira and (3) the pattern of the central cusps on the central radular tooth, are interpreted as three different species under the morphological and phylogenetic species concepts but also likely under the biological species concept, viz. A. wykoffi (sensu stricto), A. longispira sp. nov. and A. khelangensis sp. nov. The three cryptic species are (re)described and the implications of separation are briefly discussed