Seasonal variation of macromedusae (Cnidaria) at North Bay, Florianópolis, southern Brazil

Abstract

Seasonal variation of large medusae abundance and biomass was studied in the North Bay, Santa Catarina, southern Brazil (27°30'S, 48° 32'W), from February to December 2005. Collecting was conducted seasonally with the help of fishing bottom trawl in 30-minute sections (12 in summer, 18 in each of the remaining seasons) in six stations, totaling 66 samples. Eight species were found: the hydrozoans Aequorea sp., Olindias sambaquiensis Müller, 1861, and Rhacostoma atlantica L. Agassiz, 1850; the cubozoans Chiropsalmus quadrumanus (Müller, 1859) and Tamoya haplonema Müller, 1859, and the scyphozoans Aurelia sp., Chrysaora lactea Eschscholtz, 1829 and Lychnorhiza lucerna Haeckel, 1880. Capture rates were low, up to 38 indiv. ha-1, and only ~47% of the samples were positive for jellyfish, comprising 206 individuals. Medusae abundance and species richness clearly changed from one season to another, but did not vary between the sites. Higher species richness (7 out of 8) and greater abundances were recorded during the fall (~60% and 72% of all medusae individuals and biomass respectively). Specific frequency of capture varied from 1.5 to 29% and C. lactea was the only species found in more than 25% of the samples. The three most common species dominated in different periods of the year: C. lactea during fall (78% of individuals and 60% of biomass), R. atlantica during winter (90% of individuals and 17% of biomass), and O. sambaquiensis in spring (78% of individuals and 40% of biomass). Only two individuals were caught during summer, one C. lactea and one R. atlantica. The results offer a general picture of the distribution of the macromedusae in the North Bay, but a continuous monitoring is desirable for a more detailed knowledge on the jellyfish dynamics in the Brazilian coastal waters

Macromedusae of Southern Brazil: temporal variation, population structure and biochemical composition

“…The study conducted by NOGUEIRA JÚNIOR et al (2010), also on the Santa Catarina coast, reported the same species of macromedusae as those reported in this study. Their investigation also highlights great variability in density values between sampling years, and the possible influence of oceanographic conditions on the population density along the coast -as also on the reproduction of the organisms.…”

“…For both O. sambaquiensis and R. atlanticum, species common in the south of Brazil, their occurrence has been reported in high densities in waters with temperatures of between 19.5 and 21.0°C during the spring (MIANZAN; GUERRERO (2000) and NOGUEIRA , despite the different behaviors of the same species as between the southeastern and southern regions of Brazil (NOGUEIRA JÚNIOR et al, 2010). Their cohorts appear to have been more influenced by the climatic conditions in 2014, characterized by milder winters and low influence of the continental drainage (higher salinities), suggesting favorable conditions for the development of the species.…”

Biodiversity of planktonic hydrozoans from a subtropical estuary: evidence of assemblage structure change

“…Yet, the total species richness reported probably still is slightly underestimated due to the difficulty of identifying the different species of Clytia and Obelia based on medusa morphology, the notorious fragility of planktonic hydrozoans which result in damaged and unidentifiable individuals (even when relatively few) that could represent additional species. Moreover, the use of different gear types also may help to find additional species such as Rhacostoma atlanticum and Olindias sambaquiensis , not sampled here but known to commonly occur in coastal waters nearby and occasionally entering estuaries (Nogueira Júnior et al ., 2010; Nogueira Júnior, 2012). These species are usually large-sized (reaching up to >40 mm) and thus rarely sampled in standard zooplankton nets as used here (Nagata et al ., 2014a).…”

Conformação gonadal, caracterização histoquímica e ultraestrutural da gônada masculina e espermatozoides em espécies de águas-vivas (Cubozoa e Scyphozoa, Medusozoa, Cnidaria)

“…No Brasil as espécies de Scyphozoa Lychnorhiza lucerna (Rhizostomeae) e, Chrysaora lactea (Semaeostomeae) são abundantes (Morandini et al 2005;Nogueira Júnior et al 2010). As cubomedusas Tamoya haplonema (Carybdeida) e Chiropsalmus quandrumanus (Chirodropida) possuem abundância menor, mas são relativamente comuns (Nogueira Júnior et al 2010).…”

“…As cubomedusas Tamoya haplonema (Carybdeida) e Chiropsalmus quandrumanus (Chirodropida) possuem abundância menor, mas são relativamente comuns (Nogueira Júnior et al 2010). Na Austrália as espécies do gênero Cassiopea normalmente são encontrados com a umbrella apoiada no substrato e a superficie oral para cima (Bigelow 1900; Morandini et al 2016b) (Bridge et al 1995;Odorico and Miller 1997;Marques and Collins 2004;Morandini et al 2016a).…”