Phenotypic Differentiation of Ecologically Significant Brachidontes Species Co-Occurring in Intertidal Mussel Beds from the Southwestern Atlantic

Fil: Adami, Mariana Laura. División Zoología Invertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Pastorino, Guido. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia. Ciudad Autónoma de Buenos Aires; ArgentinaFil: Orensanz, J.M.. Centro Nacional Patagónico (CENPAT- CONICET). Puerto Madryn. Chubut; Argentin

Taxonomía y distribución de los poliquetos pelágicos del Atlántico Sudoccidental

This work is based on the analysis of 420 planktonic samples of 7 oceanopraphic cruises distributed over the Argentine, Uruguayan and South brasilian continental shelf (SW Atlantic ocean), as well as from some oceanic sectors, adjacent to the continental slope. Vertical hauls were performed in all stations from 100 m depth to surface, except in the Walter Herwig cruise (where vertical hauls were predominantly performed out of slope sectors, between 300 and 500 m depth to surface) and Productividad cruise in which only surface waters were hauled. A list of 27 species are determined, corresponding to 5 families: Iospilidae (3 species), Lopadorrhynchidae (4), Alciopidae (9), Typhloscolecidae (5) and Tomopteridae (6). Larvae and epitokous forms of benthonic species are not taken into account. The genus Iospilus is revised, Pariospilus and Iospilopsis being considered their synonyms; the identity of Pariospilus affinis Viguier is maintained, being transferred to the genus Iospilus. The species Vanadis studeri Apstein is redescribed and its synonymy is established. The taxonomic value of the apical glands of Tomopteris species is discussed and some specimens are found to coincide with T. kefersteini in relation to the mentioned glands. All the species found in this work are described and illustrated, a systematic key being added for their identification. Considering the vertical nature of the hauls, it was not possible to specify the habitats of the different species; for this reason they are grouped as species from subtropical and subantartic areas of influence. The first group, made up of 17 species, shows and evident graduation in its latitudinal distribution, some of them being more restricted in their distribution than the others. The second group, of 4 species, is found south to the tropical convergence, in transitional waters, towards cold sectors. The third group, of 6 species, is found to be distributed all along the continental shelf, in subtropical and subantartic regions, and extending their distribution northwards, possibly related to deep water levels. The general scheme is coincident with the distribution of other planktonic groups (Copepods, Euphausiids). As a general feature, neither coastal nor shelf water specimens of pelagic Polychaeta were found, with exception of T. septentrionalis. A comparison with the results in Tebble's paper (1960) in the southwest Atlantic ocean is made, 12 of our species being coincidently found in the same hydrological area by that author. The drift of the main water masses of the South Atlantic ocean is accepted as a possible cause for the distribution of the pelagic Polychaeta of the southwest Atlantic regions

Onuphidae (Annelida, Polychaeta) da região de Ubatuba, litoral norte do estado de São Paulo, Brasil Onuphidae (Annelida, Polychaeta) from Ubatuba, north coast of the São Paulo State, Brazil

<abstract language="eng">Ten species of onuphid polychaetes were identified from the sublitoral of Ubatuba, on the coast of the state of São Paulo, Brazil: Diopatra cuprea (Bosc, 1802); Diopatra tridentata Hartman, 1944; Kinhergonuphis difficilis (Fauchald, 1982); Kinhergonuphis fauchaldi Lana, 1991; Kinhergonuphis orensanzi (Fauchald, 1982); Kinhergonuphis tenuis (Hansen, 1882); Mooreonuphis nebulosa (Moore, 1911); Mooreonuphis pallidula (Hartman, 1965); Mooreonuphis intermedia (Kinberg, 1865); Onuphis dibranchiala Willey, 1905. A discussion on the characteristics of the species found and related species is also provided

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