Leonardo F. Machado

Reproductive biology of the dusky grouper Epinephelus marginatus (Lowe, 1834)

Este trabalho trata sobre a biologia reprodutiva da garoupa verdadeira, Epinephelus marginatus (Lowe, 1834) um peixe teleosteo pertencente a familia Serranidae, hermafrodita protoginico e caracteristico do litoral rochoso, que vive desde aguas rasas ate os 200 m de profundidade. As amostragens foram realizadas nas ilhas que compoem a Reserva Biologica Marinha do Arvoredo (SC) e ilhas costeiras proximas da regiao de Florianopolis entre marco de 1998 e maio de 2000. Dados de coletas de juvenis em pocas de mares foram utilizados visando relacionar a sua ocorrencia nestes ambientes com o periodo de pos-reproducao. Procedeu-se a analise histologica de 109 exemplares, a partir da qual foram descritas as alteracoes histologicas nas gonadas ao longo do seu ciclo sexual e foram estabelecidas as escalas de maturacao. Desta forma determinou-se um tamanho de primeira maturacao para as femeas (L50=470 mm; r2=0,99). O comportamento dos valores dos indices calculados (Indice Hepatossomatico (IHS) e Indice Gonadossomatico (IGS)) elucidou um periodo reprodutivo com maturacao das gonadas ao longo dos meses de primavera, vindo a desovar na estacao do verao, sendo nitida a recuperacao do figado (elevacao do IHS) no outono, pos reproducao. Calculou-se tambem a relacao peso comprimento P = 9 · 10-6 · CT 3,1149 (r2=0,998; n=246).

Diversity and seasonal changes in the ichthyofauna of rocky tidal pools from Praia Vermelha and São Roque, Santa Catarina

A survey of the tidal pool fish community was carried out between April 1998 and May 1999, at the beaches of Praia Vermelha (PV) and Sao Roque (SR), Santa Catarina, Brazil. The pool of PV was bigger and closer to the subtidal. Specimens were collected monthly at low tide, using quinaldine. In PV we collected 1287 fish belonging to 19 species and in SR 553 fish were caught corresponding to 11 species. In both pools, dominant species were Bathygobius soporator (Gobiidae), Abudefduf saxatilis (Pomacentridae), Parablennius pilicornis (Blenniidae), Gobiesox barbatulus (Gobiesocidae), Labrisomus nuchipinnis (Labrisomidae) and Epinephelus marginatus (Serranidae). Summer months had higher abundance and diversity values, and correspond to a recruitment season for both A. saxatilis and E. marginatus.

Space–Time Distribution of the Ichthyofauna from Saco da Fazenda Estuary, Itajaí, Santa Catarina, Brazil

Abstract From July 2003 to June 2004, the physiographic characteristics of the ichthyofauna of the estuary of Saco da Fazenda were studied in four defined areas representative of the estuary. A total of 4502 individuals were captured, with 42 species, 35 genera, and 21 families. Engraulidae were the most abundant fish, and Cetengraulis edentulus dominated the captures. The species of occasional occurrence prevailed in the samplings and were represented mainly by juvenile individuals. The highest abundances occurred during the months of summer and autumn, in contrast with high biomasses in the spring and autumn; area IV contributed the largest captures. The richness indexes, diversity, and equitability presented similar flotation patterns, with high values in spring and summer. The Jaccard index revealed a greater similarity in the composition of the ichthyofauna in areas II and IV, while the lowest happened between I and IV, which is probably due to the different sizes of these areas. This paper clearly shows the relevance of this estuary, albeit strongly impacted, for recruitment of small fish mainly during summer and autumn months.

Cleaning activity among Labridae in the Azores: the rainbow wrasse Coris julis and the Azorean blue wrasse Centrolabrus caeruleus

Cleaning interactions among the rainbow wrasse Coris julis and the azorean blue wrasse Centrolabrus caeruleus are presented with photographic registers, as well as the first record of the latter cleaning conspecifics from Azorean shallow rocky reefs.

Rocky reef fish community structure in two Azorean islands (Portugal) central North Atlantic

The community structure of shallow rocky reef fish fauna of the Azores Archipelago is described from underwater visual censuses carried out at eight areas (Terceira and Corvo Islands). A total of 52 fish species from 26 different families was observed, and the ten most abundant fish corresponded to 82.7% of all fish. Trophic categories are given for observed species with comments on distribution and densities along sampled depth strata. Mean densities along sampled strata were tested for significant differences. Sparidae, Labridae and Carangidae were the most speciose families being Diplodus sargus, Pagellus acarne, Coris julis, Thalassoma pavo and Tripterygion delaisi the most abundant species that consequently also accounted for the highest densities.

Cleaning interactions between the cleaner wrasse Symphodus melanocercus (Osteichthyes: Labridae) and brown meagre Sciaena umbra (Osteichthyes: Sciaenidae)

Cleaning interactions between the wrasse Symphodus melanocercus and brown meagre Sciaena umbra are documented from observations whilst free diving on a shallow rocky reef in the central Mediterranean Sea. Cleaning events occurred at cleaning stations mainly during the morning and gradually decreased in the evening. The body parts mostly cleaned were the opercular region and the fins, possibly as gnathiid isopods preferentially attach to these areas.