Resource competition and sexual selection in the European lobster

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Effect of fragmentation, habitat loss and within-patch habitat characteristics on ant assemblages in semi-arid woodlands of eastern Australia.

The reliability of ants as bioindicators of ecosystem condition is dependent on the consistency of their response to localised habitat characteristics, which may be modified by larger-scale effects of habitat fragmentation and loss. We assessed the relative contribution of habitat fragmentation, habitat loss and within-patch habitat characteristics in determining ant assemblages in semi-arid woodland in Queensland, Australia. Species and functional group abundance were recorded using pitfall traps across 20 woodland patches in landscapes that exhibited a range of fragmentation states. Of fragmentation measures, changes in patch area and patch edge contrast exerted the greatest influence on species assemblages, after accounting for differences in habitat loss. However, 35% of fragmentation effects on species were confounded by the effects of habitat characteristics and habitat loss. Within-patch habitat characteristics explained more than twice the amount of species variation attributable to fragmentation and four times the variation explained by habitat loss. The study indicates that within-patch habitat characteristics are the predominant drivers of ant composition. We suggest that caution should be exercised in interpreting the independent effects of habitat fragmentation and loss on ant assemblages without jointly considering localised habitat attributes and associated joint effects

A morphometric analysis of Eunice Cuvier (Annelida, Polychaeta) species

Morphology has been the subject of several studies in Eunice specially in the context of the taxonomy and evolutionary relationships of taxa within this genus. In this study we opt for a morphometric approach comparing five species of Eunice to assess if it was possible to delimitate them by shape variables. The morphology of E.fucata, E.insularis, E. cf. ornata, E.rubra, and Eunice sp. was compared using traditional morphometric analysis of 16 measured variables. After removing the size-effect, a Canonical Variates Analysis applied to morphometric variables was able to discriminate all species. In CV1 two major groups of species were discriminated: E.fucata/E.insularis and E. cf. ornata/E.rubra/Eunice sp. CV2 strongly discriminated all species, with E. cf. ornatawith higher scores and E.rubra with lower ones. The characters that differentiate the species were the relative size of antennae, peristomium and anteriormost setigers. This study also demonstrated that peristomium width and palps length were the best variables for body size estimation in Eunice, since they were highly correlated to the size-estimator. Through morphometric analysis it was possible to delimitate species and choose diagnostic characters for the genus Eunice, a result likely to be valid for other polychaete species.<br>Estudos morfológicos em Eunice são muito comuns, especialmente em um contexto taxonômico e de relações evolutivas de táxons deste gênero. Neste estudo, optamos por uma abordagem morfométrica comparando cinco espécies de Eunice para avaliar a possibilidade de delimitá-las através de variáveis de forma. A morfologia de E.fucata, E.insularis, E. cf. ornata, E.rubra e Eunice sp. foi comparada utilizando-se análises de morfometria tradicional de 16 variáveis mensuradas. Após a remover o efeito de tamanho, uma Análise de Variáveis Canônicas aplicada às variáveis morfométricas permitiu a discriminação de todas as espécies. Em CV1, dois grupos maiores de espécies foram discriminadas: E.fucata/E.insularis e E. cf. ornata/E.rubra/Eunice sp. CV2 discriminou fortemente todas as espécies com E. cf. ornataapresentando escores maiores e E.rubra os menores. Os caracteres que diferenciaram as espécies foram o tamanho relativo das antenas, do peristômio e dos setígeros anteriores. Este estudo também demonstrou que a largura do peristômio e o comprimento dos palpos são as melhores variáveis para estimar o tamanho do corpo em Eunice, já que ambas estiveram altamente correlacionadas com o estimador de tamanho. Através de análises morfométricas foi possível delimitar as espécies e escolher caracteres diagnósticos para o gênero Eunice, um resultado provavelmente válido para outras espécies de poliquetas