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

Abstract

Investigations were carried out about the reproductive biology of the dusky grouper, Epinephelus marginatus (Lowe, 1834) a serranid protogynous hermaphrodite fish inhabitant of rocky bottoms from shallow waters up to 200 m depth. Samples were caught in the islands that form Arvoredo Biological Marine Reserve (SC - Brazil) and the coastal islands near Florianópolis region from March 1998 to May 2000. Data from samples of juvenile groupers on intertidal pools were used to link their occurrence in the pools to the post-spawning season. To describe the histological changes on gonads along the reproductive cycle and to establish maturation scales, 109 groupers were histologically tested for sex determination. First maturation size was determined for females (L50=470 mm; r²=0.99). The results of calculated gonadosomatic (GSI) and hepatosomatic (HSI) indexes, showed that maturation occurred along the spring months and the spawning activity during the summer with a peak in December. Liver recovery (HSI elevation) was evident in the autumn, was the post spawning season. The relationship between length and weight was W = 9 · 10-6 · TL3.1149 (r²=0.998; n=246).<br>Este trabalho trata sobre a biologia reprodutiva da garoupa verdadeira, Epinephelus marginatus (Lowe, 1834) um peixe teleósteo pertencente à família Serranidae, hermafrodita protogínico e característico do litoral rochoso, que vive desde águas rasas até os 200 m de profundidade. As amostragens foram realizadas nas ilhas que compõem a Reserva Biológica Marinha do Arvoredo (SC) e ilhas costeiras próximas da região de Florianópolis entre março de 1998 e maio de 2000. Dados de coletas de juvenis em poças de marés foram utilizados visando relacionar a sua ocorrência nestes ambientes com o período de pós-reprodução. Procedeu-se à análise histológica de 109 exemplares, a partir da qual foram descritas as alterações histológicas nas gônadas ao longo do seu ciclo sexual e foram estabelecidas as escalas de maturação. Desta forma determinou-se um tamanho de primeira maturação para as fêmeas (L50=470 mm; r²=0,99). O comportamento dos valores dos índices calculados (Índice Hepatossomático (IHS) e Índice Gonadossomático (IGS)) elucidou um período reprodutivo com maturação das gônadas ao longo dos meses de primavera, vindo a desovar na estação do verão, sendo nítida a recuperação do fígado (elevação do IHS) no outono, pós reprodução. Calculou-se também a relação peso comprimento P = 9 · 10-6 · CT 3,1149 (r²=0,998; n=246)

Population structure and reproductive biology of Loricariichthys melanocheilus Reis & Pereira, 2000 (Siluriformes: Loricariidae) in the rio Ibicuí, Brazil

“…Some researchers have established relationships between hepatosomatic index and reproductive cycles of several species (Agostinho et al, 1990;Querol et al, 2002;Andrade et al, 2003;Costa et al, 2005;Cantanhêde et al, 2007;Viana et al, 2008). According to Agostinho et al (1990), gonad maturity and reproductive activity imply the use of materials obtained from ingested food and mostly from energy reserves deposited in different parts of the body.…”

Age, growth, and reproductive aspects of the dusky grouper Mycteroperca marginata (Actinopterygii: Epinephelidae) in a man-made rocky habitat in southern Brazil

“…Like other Serranidae species, the dusky grouper is characterized by slow growth, sedentary and territorial behavior, and a complex reproductive strategy (protogynous hermaphroditism) (Chauvét, 1991;La Mesa et al, 2002;Andrade et al, 2003;Fennessy, 2006). These biological features make this species particularly vulnerable to anthropogenic threats like increasing fishing pressure (Manooch, 1987;Falcón et al, 1996;Cornish & HarmelinVivien, 2004).…”

Reef fishes of the Anchieta Island State Park, Southwestern Atlantic, Brazil

“…Among actinopterygians, it is remarkable that 83.3% of the recorded epinephelids (groupers) are either CR, EN, VU or NT. Besides being protogynous hermaphrodites, epinephelids are slow-growing and long-living species with late maturity (Andrade et al 2003, Mitcheson et al 2008, Reñones et al 2010, being thus highly vulnerable to fishery.…”