Matheus Oliveira Freitas

Omobranchus punctatus (Teleostei: Blenniidae), an exotic blenny in the Southwestern Atlantic

The muzzled blenny Omobranchus punctatus (Valenciennes), native to the Indo-Pacific region, is recorded in the Southwestern Atlantic coast, inhabiting natural and artificial substrates in the proximities of three large Brazilian seaports (states of Bahia, Rio de Janeiro and Santa Catarina). Due to its habitat and habits, the introduction of this species was probably by ship or oil rigs, presumably associated within fouling. It is also argued that the muzzled blenny can maintain populations in natural and artificial (mariculture facilities) coastal environments in the Southwestern Atlantic.

Feeding ecology of Lutjanus analis (Teleostei: Lutjanidae) from Abrolhos Bank, Eastern Brazil

Diet and feeding ecology of the mutton snapper Lutjanus analis were investigated in the Abrolhos Bank, Eastern Brazil, the largest and richest coral reefs in the South Atlantic, where about 270 species of reef and shore fishes occur. To evaluate seasonal and ontogenetic shifts in the diet, specimens of L. analis were obtained through a fish monitoring program in four cities in southern Bahia State, from June 2005 to March 2007. Stomachs from 85 mutton snappers that ranged in size from 18.1 to 74.0 cm TL were examined. Prey were identified to the lowest possible taxon and assessed by the frequency of occurrence and volumetric methods. Variations in volume prey consumption were evaluated using non-metric multi-dimensional scaling ordination, analysis of similarity, and similarity percentage methods. Significant differences in diet composition among size classes were registered, whereas non significant differences between seasons were observed. Considering size-classes, food items consumption showed important variations: juveniles ( 50.1 cm TL) consumed basically fish, mostly Anguiliformes. Lutjanus analis is an important generalist reef predator, with a broad array of food resources and ontogenetic changes in the diet. This snapper species plays an important role on the trophic ecology of the Abrolhos Bank coral reefs.

Age and growth of the dog snapper Lutjanus jocu (Bloch & Schneider, 1801) in Abrolhos Bank, Northeastern Brazil

We determined the age and growth of the dog snapper (Lutjanus jocu), caught in the region of Abrolhos Bank, Bahia State, by the fishermen from coastal communities of Prado, Alcobaca, Caravelas, and Nova Vicosa. We examined 205 sectioned otoliths of fish caught by harpoon, longline, hand line, and gill nets (14.5 to 79.5 cm fork length). The formation of each ring was considered annual. The sectioned otoliths showed between 0 and 29 rings. Nearly half of the analyzed specimens had between 0 and 7 rings (88 of 205). Fish caught with nets in the estuarine region were the juvenile, while fish caught with lines and harpoons were the oldest. Two von Bertalanffy growth models were fitted to length-at-age data: one assuming constant variance of length-at-age (SVB) and another assuming constant coefficient of variation, i.e. variance increasing as a function of average size (CVVB). The SVB estimates were Loo = 87.82 cm, K = 0.10, and t0 = -1.486 and the CVVB estimates were Loo = 117.60 cm, K = 0.06, and t0 = -2.470. The largest Loo values estimated by the CVVB model are supported by reports from the literature of larger animals occurring in the deeper outer shelf of Abrolhos Bank. Growth parameters were also estimated for males and females separately (SVB model) (Loo = 92.80 cm, K = 0.099, and t0 = -1.680 for males, and Loo = 82.10 cm, K = 0.105, and t0 = -1.570 for females).

Diet and reproduction of the goliath grouper, Epinephelus itajara (Actinopterygii: Perciformes: Serranidae), in eastern Brazil

1 Instituto Meros do Brasil, Brazil 2 Grupo de Pesquisa em Ictiofauna – GPIC, Museu de Historia Natural Capao da Imbuia, Curitiba, PR, Brazil 3 Programa de Pos-Graduacao em Zoologia, Universidade Federal do Parana, Curitiba, PR, Brazil 4 Programa de Pos-Graduacao em Ecologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil 5 Universidade Federal do Espirito Santo – UFES-DCAB – CEUNES, Sao Mateus, ES, Brazil 6 Instituto de Biologia, Depto de Biologia Marinha, Universidade Federal do Rio de Janeiro. Rio de Janeiro, RJ, Brazil 7 Universidade Federal da Paraiba, Centro de Ciencias Aplicadas e Educacao, Campus IV – Litoral Norte, Rio Tinto, PB, Brazil 8 Nucleo de Pesquisas em Limnologia Ictiologia e Aquicultura, Universidade Estadual de Maringa, Maringa, PR, Brazil 9 Inter-American Tropical Tuna Commission, La Jolla, CA, USA (present address)

Feeding ecology of two sympatric species of large-sized groupers (Perciformes: Epinephelidae) on Southwestern Atlantic coralline reefs

A garoupa e o badejo-verdadeiro sao predadores oportunistas de grande porte, com estrategia de emboscada, comumente encontrados em recifes tropicais do Atlântico Sul. A dieta das duas especies foi investigada, avaliando influencias ontogeneticas, espaciais e temporais, assim como a sobreposicao no uso de recursos entre estes dois predadores co-orrentes no Banco dos Abrolhos, Brasil. Decapodes e peixes foram os principais itens alimentares de Epinephelus morio, enquanto que os peixes foram as principais presas de Mycteroperca bonaci. Ambas as dietas foram significativamente influenciadas pelo tamanho corporal e habitat, mas apenas individuos menores de E. morio alimentaram-se quase que exclusivamente de crustaceos. Como as duas especies utilizam muitas presas semelhantes, a coexistencia parece ser facilitada pelo fato de E. morio se alimentar principalmente de crustaceos, particularmente do caranguejo Cronius ruber, enquanto que o badejo-verdadeiro consome relativamente poucos crustaceos e grande quantidade de peixes. Predadores como as especies estudadas podem causar efeitos indiretos na comunidade e influenciar uma grande variedade de processos ecologicos, como conexoes entre predadores de topo e intermediarios e predadores intermediarios e seus recursos.