Estudo faunístico e da distribuição das hidromedusas (Cnidaria, Hydrozoa) da região compreendida entre Cabo Frio (RJ) e Cabo de Santa Marta Grande (SC), Brasil

Abstract

Brazil has an extensive marine coast of over 9.200 km. However, the taxonomical, biogeographical and ecological knowledge of the organisms present in coastal and neritic waters is scanty. Although the gelatinous plankton constitutes one of the main groups of pelagic predators, is abundant and relatively large, in size, it is usually underestimated in number and importance by the traditional sampling methods. Hydrozoa are one of the most numerous and common groups in this planktonic community. Among the works on hydromedusae, only some included extensive areas of the Brazilian continental shelf, although sampling of oceanographic expeditions, as the ones accomplished by the Instituto Oceanográfico of the Universidade de São Paulo (IO-USP), are available for study. The goal of this study is to survey the hydromedusae species collected by two oceanographic expeditions by the Brazilian vessel carried out by IO-USP along the continental shelf between Cabo Frio (RJ) and Cabo de Santa Marta Grande (SC) (South Brazil Bight-SBB), in 1991 and 2001: Sardinha 1 and PADCT 2. The diversity and geographic distribution of the hydromedusae fauna were analyzed. Data were interpreted trying to infer correlations in the distribution of the species with the characteristic water masses present in the area (Coastal Water-CW; Tropical Water-TW; South Atlantic Central Water-SACW). The distribution data were also used in a Parsimony Analysis of Endemicity (PAE), to verify possible endemic areas of the species. From the 155 samples a total of 51,808 hydromedusae specimens were found, belonging to 20 species/morphotypes: 10 Anthoathecata; 5 Leptothecata; 3 Trachymedusae; 2 Narcomedusae. The diversity and abundance of the species were lower in the samples of PADCT 2 when compared to Sardinha 1. All of the species had already been recorded for the Brazilian coast; however, some had their geographical distributions enlarged. Liriope tetraphylla and Aglaura hemistoma were the most frequent and abundant species in the samples of the Sardinha 1 and PADCT 2, respectively. There are indications that the geographical distributions of some species are associated, as Aglaura hemistoma and Corymorpha gracilis; Solmundella bitentaculata and the pair Aglaura hemistoma-Liriope tetraphylla; Turritopsis nutricula and Proboscidactyla ornata, the last association usually occurring when both species are abundant. The relative low number of hydromedusae species found in SBB can be consequence of the sampling method, which did not aim at the gelatinous plankton. However, among the 20 identified species/morphotypes are the most frequent species already recorded for SBB, as Aglaura hemistoma, Liriope tetraphylla, Rhopalonema velatum, Solmundella bitentaculata and Turritopsis nutricula.. Some species distributions are associated to specific water masses like Turritopsis nutricula, Niobia dendrotentaculata, Proboscidactyla ornata, Solmundella bitentaculata and Corymorpha gracilis in a mixture of SACW and CW. Most individuals of Liriope tetraphylla and Eucheilota duo...

Spatial and temporal variation of planktonic cnidarian density in subtropical waters of the Southern Brazilian Bight

“…(medusae and polyps) decreased in abundance toward the outer stations. The most abundant species, the medusa L. tetraphylla, is particularly abundant in the highly productive waters off estuaries and also within estuaries, such as Cananéia (24.58S), Paranaguá (258S) and Babitonga (25.58S) bays in Brazil (Vannucci, 1957;Montú & Cordeiro, 1988;Tronolone, 2007;Nogueira, 2012); and also in the temperate waters of the La Plata Estuary (368S) (Zamponi & Genzano, 1994;Mianzan et al, 2000). A few siphonophores are restricted to or prefer coastal and estuarine waters, such as M. kochi along the SBB (Abreu & Nogueira, 1989;Cordeiro & Montú, 1991;Nogueira & Oliveira Jr, 1991;Nogueira, 2012).…”

“…Liriope tetraphylla and M. kochi exhibited similar patterns of spatial and temporal distribution, and may be among the most important planktonic predators in these shallow coastal waters. (Vannucci, 1963;Navas-Pereira, 1981;Cordeiro & Montú, 1991;Tronolone, 2007). We found a clear preference for the Stations 4 and 5 by C. gracilis; however, its preference for shelf waters, as previously suggested for the SBB (Vannucci, 1957(Vannucci, , 1963Tronolone, 2007; this study) contrasts with several occurrences in the estuarine waters of Sepetiba Bay (22.58S), Paranaguá Bay (258S) and Babitonga Bay (268S), where it was found in salinities ≥22 (Montú & Cordeiro, 1988;Navas Pereira, 1980;Nogueira, 2012).…”

<strong>Faunistic survey of Hydromedusae (Cnidaria, Medusozoa) from the coast of Paraná State, Southern Brazil</strong>

“…This number is likely less than the true species richness, since most of the 8500 km of the Brazilian coastline has scarcely or never been studied, including the coast of Paraná State (Marques et al 2003). Faunistic knowledge of this region is based on isolated studies, from oceanographic campaigns that revealed overall mesoscale patterns of spatial distributions and correlations of species with the main water masses on the South Brazilian Bight (SBB) (Vannucci 1957;Correia 1983;Tronolone 2007). However, extensive sampling (e.g., standardized continuous sampling) has not been carried out along the shelf off Paraná, and consequently the regional diversity and its dynamics are insufficiently known.…”

Preliminary assessment of the jellyfish bycatch captured off southern and southeastern Brazil

“…In Brazil there are about 22 species of Scyphozoa, 4 Cubozoa (Morandini et al, 2005) and more than 20 morphotypes of Hydrozoa only in the southeast and south regions (Tronolone, 2008). The occurrence of jellyfish as bycatch in shrimp artisanal fisheries has already been highlighted by Branco & Verani (2006) in Armação do Itapocoroi bay in Santa Catarina.…”