RESUMO
Tubastraea coccinea Lesson, 1830 and T. tagusensis Wells 1982 are azooxanthellate corals non-native to Brazil and introduced through fouling on oil platforms, the primary vector. They first invaded the tropical rocky reefs at Ilha Grande Bay (southwest Atlantic Ocean), during the early 1990s. Currently, at some Brazilian locations these species occupy 80% of the benthos of the shallow subtidal. They cause economic and environmental impacts by fouling shipping and modifying native communities. This study provides observations of an additional mechanism of secondary dispersal by T. coccinea and T. tagusensis that were seen attached to floating wood debris and marine litter, which are highly abundant in the region. Such rafting corals have been found adjacent to invaded reefs and stranded on beaches. These observations indicate that transport by rafting over long distances may be another mechanism of range expansion and secondary introduction of these invasive species within the region.
Assuntos
Antozoários , Animais , Oceano Atlântico , Brasil , Ecossistema , Espécies Introduzidas , MadeiraRESUMO
Teredinidae (shipworms) is a family of marine wood-boring bivalves that has an important role in the degradation of wood through its symbiotic relationship with cellulolytic bacteria. To evaluate the rate of degradation of wood by teredinids in two sites with different oceanographic conditions in Rio de Janeiro State, Brazil, artificial structures composed of pine wood sheets were immersed in the ocean for three months at Arraial do Cabo in an area under the influence of upwelling, and at Ilha Grande Bay under tropical and oligotrophic influences. After the immersion period, teredinids were removed from the collectors, identified, and counted. Wood consumption by the teredinids was quantified by comparing the dry weights of the collectors before and after immersion. Associated bacteria were isolated and their cellulolytic activities evaluated at different temperatures and salinities. Two Teredinidae species were recorded: Bankia gouldi and Lyrodus floridanus. The highest wood degradation rate and enzymatic activities of the isolated bacterial strains were recorded at Arraial do Cabo, suggesting that upwelling influenced the activities of those species.
Assuntos
Bivalves , Madeira , Animais , Bactérias , Brasil , Brânquias , Salinidade , TemperaturaRESUMO
Species of Serpulidae are common on benthic and biofouling communities, occurring attached on both natural and artificial substrates. In this paper, Serpulids were collected from intertidal to subtidal areas, on rocky shore and suspended artificial plates in port areas. Herein we report three new records of serpulid species to the coast of Rio de Janeiro, Brazil. We also discuss the misidentification of Spirobranchus tetraceros, which was previously reported to the north of Rio de Janeiro.
Assuntos
Animais , Anelídeos/anatomia & histologia , Anelídeos/classificação , Classificação , Distribuição Animal , BrasilRESUMO
Species of Serpulidae are common on benthic and biofouling communities, occurring attached on both natural and artificial substrates. In this paper, Serpulids were collected from intertidal to subtidal areas, on rocky shore and suspended artificial plates in port areas. Herein we report three new records of serpulid species to the coast of Rio de Janeiro, Brazil. We also discuss the misidentification of Spirobranchus tetraceros, which was previously reported to the north of Rio de Janeiro.(AU)
Assuntos
Animais , Anelídeos/anatomia & histologia , Anelídeos/classificação , Distribuição Animal , Classificação , BrasilRESUMO
The genus Pyura is widely distributed with 99 valid species. Since 1961, Pyura vittata (Stimpson, 1852) has been reported to the Southwest Atlantic but new collections and a revision of the morphological characters of samples deposited in scientific collections revealed that samples had been confused with two other species: Pyura gangelion (Savigny, 1816) and Pyura beta sp. nov. present in the Caribbean sea and Brazil. In Brazil, P. vittata is not present south to Bahia, P. beta was found from Espírito Santo to São Paulo, while P. gangelion was only found in Espírito Santo, and we suggest that populations of both P. beta and P. gangelion are non-native in Brazil.
Assuntos
Urocordados , Animais , Brasil , Região do CaribeRESUMO
El crecimiento del cirripedio intermareal Tetraclita stalactifera fue comparado en dos sitios influenciados por condiciones de resurgencia y tropicales en la región del Cabo Frio, Brasil. La hipótesis fue que el crecimiento es más grande en el sitio con más elevada producción. En esta región, cinco cuadrantes de 10 x 10 cm fueron raspados en el intermareal de las costas rocosas, en cada una de estas localidades, para estudiar el crecimiento de T. stalactifera desde el reclutamiento hasta finalizar el experimento o la muerte del individuo. El diámetro de la base de T. stalactifera fue medido para 18 individuos en el sitio tropical (Ponta da Fortaleza) y 22 en el sitio de resurgencia (Ponta da Cabeza) por medio de fotografías digitalizadas y el software ImageTool. Los resultados observados mostraron una mayor tasa de crecimiento en el área bajo la influencia tropical (0.07 mm/día) que en el área bajo influencia de resurgencia (0.06 mm/día). La localización del sitio, periodo de resurgencia o periodo del asentamiento no afectaron las tasas de crecimiento. Otros efectos o interacciones sinérgicas como la temperatura y la disponibilidad de alimento pueden afectar el crecimiento de esta especie en la región.
Growth of the intertidal barnacle Tetraclita stalactifera was compared in two sites under upwelling and tropical influence at Cabo Frio region, Brazil. The hypothesis was that growth is higher at sites with an enhanced productivity. Five quadrates of 10 x 10 cm were cleared in an intertidal zone of each site to follow growth from recruitment and onwards. Base diameters were measured for 18 individuals at the tropical site (Ponta da Fortaleza) and 22 at the upwelling site (Ponta da Cabeça) using digitalized photos and ImageTool software. Mean growth rates were 0.07 mm/day at the tropical site and 0.06 mm/day at the site under upwelling influence. No effect of location, upwelling season or settlement time was found on barnacle growth rates. Other factors or synergic interactions such as temperature and food availability could influence T. stalactifera growth.
Assuntos
Animais , Comportamento Animal/fisiologia , Thoracica/crescimento & desenvolvimento , Ecossistema Tropical , Brasil , Comportamento Alimentar/fisiologia , Estações do Ano , TemperaturaRESUMO
A rugosidade dos substratos afeta o assentamento de larvas de invertebrados marinhos, tanto em substratos naturais quanto em substratos artificiais. Elevadas taxas de assentamento são esperadas em substratos com maior rugosidade/ heterogeneidade devido aos microhabitats formados e também à alteração do movimento da água sobre o substrato. Neste estudo foi avaliado o assentamento de cracas em substratos lisos e rugosos, dispostos na região de Cabo Frio, RJ, Brasil (220 59' S, 420 02' W). Dez blocos de granito comercial (100 cm2) foram fixados ao costão rochoso no nível de maré 0,6. Cinco blocos eram lisos (controle) e cinco blocos apresentavam 20 pequenas cavidades (5 mm f , 3mm profundidade) regularmente distribuídas no bloco. O experimento foi conduzido por 7 dias e repetido em 5 semanas. Como resultado observamos o maior assentamento nos blocos rugosos (Max. 398 indivíduos) do que nos blocos lisos (Max. 38 ind.). Não foi observada diferença significativa entre o número de assentados no centro do bloco em relação à sua margem, indicando que não houve o efeito de borda. Foram observadas diferenças significativas no assentamento entre as 5 semanas do experimento, afetada pela maior presença de larvas cípris durante algumas semanas. Este experimento mostra como a variabilidade estrutural pode influenciar o assentamento de larvas de Cirripedia.