Appendicularian species groups and southern Brazil water masses

Abstract

The distribution of 19 species of appendicularia sorted out of a series of plankton samples taken between Cabo Frio (lat. 23º S) and Rio Grande do Sul (lat. 36º S) is discussed in relation to temperature and salinity. Most species showed a wide spectrum of temperature and salinity tolerance. No species was found to be exclusive of a single water mass. Eleven species were present in coastal waters, 16 in shelf waters and 13 in tropical waters. Ten species were found in the three water masses. Oikopleura longicauda was the most abundant species and O. dimca was found only over the shelf. Species of the genus Fritillaria were more sensitive to lower salinities and in a general way the number of species decreases coastalwards. Different groups of species were present in the same water mass and conversely similar groups occurred in different water masses. Five, eight and nineteen different groups of species occurred exclusively in shelf, coastal and tropical waters respectively. There was suggested the occurrence of stratified distribution and consequently the presence of different ecological niches within a single water mass. Several species probably reproduce more than once, most species are proterandric. Parasites and predators are mentioned. It is suggested that the knowledge of the past history of the water mass and its biological dynamics are more important for the interpretation of the distribution of the appendicularian fauna than temperature and salinity factors alone.

Variação da composição e abundância das espécies da Classe Appendicularia e seu uso como potenciais bioindicadoras de regiões e massas de água superficiais na área da Bacia de Campos, Rio de Janeiro, Brasil

“…Esnal, 1999;Tomita et al, 2003;Shiganova, 2005;Bonecker & Carvalho, 2006;Carvalho & Bonecker, 2010;Touzri et al, 2012). A ocorrência exclusiva de O. dioica na AC, água caracterizada por ser rica em nutrientes, pode estar relacionada ao fato de que essa espécie tem uma necessidade maior de alimentos do que as outras apendiculárias (Tomita et al, 2003 (Forneris, 1965), mas como no presente estudo, já foram encontradas em águas de plataforma e oceânicas na costa do Japão (Hidaka, 2008). Os maiores valores de densidade de O. rufescens foram encontrados sobre a influência da AT no período chuvoso.…”

“…A preferência de O. rufescens por uma determinada massa de água superficial ainda não foi descrita, mas sabe-se que essa espécie é frequentemente encontrada em regiões costeiras (Carvalho & Bonecker, 2010) e oceânicas (Hidaka, 2008) de águas quentes da região tropical (Aravena & Palma, 2002). Fritillaria formica apresentou preferência pela AT; esta espécie é considerada oceânica (Zakaria, 2006) e assim como no atual estudo, apresentou preferência pela AT em águas oceânicas no sul do Brasil (Forneris, 1965).…”

“…Alguns autores caracterizam as espécies de apendiculária como boas bioindicadoras de massas de água (Forneris, 1965;Hsiao et al, 2011). Algumas espécies mostraram uma preferência por águas continentais com mistura de águas oceânicas no Atlântico Sul Ocidental (Björnberg & Forneris, 1956;Capitanio & Esnal, 1997) apesar disso, pouco se conhece sobre a variação espacial (plataforma e talude), sobre as preferências hidrológicas e a função de bioindicadoras das espécies de apendiculárias.…”

Seasonal and spatial variability of appendicularian density and taxonomic composition in the Caravelas Estuary (Northeastern Brazil) and adjacent coastal area

“…Fenaux (1968) them considered as the two most important appendicularians off the Brazilian coast. Among the species found exclusively at the ocean stations, O. cornutogastra was characteristic of shelf waters (Forneris, 1965). O. albicans is characteristic of ocean waters, and is generally absent from the coastal regions (Esnal and Castro, 1977).…”

“…Appendicularians are numerically well represented, after the Copepoda, in coastal and estuarine environments. Studies on the distribution, specific composition, and abundance of appendicularians in oceanic regions of the southwest Atlantic have been carried out by several investigators, e.g., Lohmann (1896Lohmann ( , 1931, Lohmann and Buckmann (1926), Hentschell (1939), Fenaux (1967), Björnberg and Forneris (1956a, 1956b, 1958, Forneris (1965), Tundisi (1970), Esnal (1999), Campos (2000), and Bonecker and Carvalho (2006). Some studies have been carried out in coastal regions, where only species of the family Oikopleuridae (Bonecker et al, 1991;Vega-Pérez, 1993;Bonecker et al, 1998;Dias et al, 1999;Biancalana et al, 2005).…”