RESUMOCom o principal objetivo de fornecer ferramentas para auxiliar na implementação do manejo sustentável de peixes ornamentais na Reserva de Desenvolvimento Sustentável Amanã, Amazonas, foi realizado o estudo da biologia reprodutiva de Heros efasciatus Heckel, 1840, um ciclídeo com potencial ornamental e com poucos trabalhos sobre a sua biologia e ecologia, apesar de já ser comercializado em algumas regiões amazônicas. Coletas bimestrais foram realizadas de fevereiro de 2006 a janeiro de 2007 em dez igarapés contribuintes do Lago Amanã e Urini, sendo utilizados três aparelhos de pesca (rede de arrasto, rapiché e armadilha tipo matapi) e ainda galhadas artificiais nas amostragens realizadas próximas aos lagos. Foram capturados 140 exemplares de H. efasciatus, sendo 50 fêmeas, 42 machos, e 46 indivíduos cujo sexo não foi identificado devido ao pequeno tamanho. O tipo de crescimento encontrado foi isométrico, sendo que o maior indivíduo observado apresentava 174 mm e o menor 14 mm. Os resultados encontrados auxiliarão na adoção de medidas de manejo, como a determinação de tamanhos mínimos de captura, superiores aos tamanhos médios de maturação (97 mm para as fêmeas) e o estabelecimento de períodos de defeso durante a época de sua reprodução (outubro a janeiro). A pequena abundância de indivíduos da espécie, quando comparada com o total de exemplares capturados (apenas 0,07%) e a baixa fecundidade média, de 2502 ovócitos, indica que se deve trabalhar anualmente apenas com um pequeno número de indivíduos, a fim de garantir a continuidade do estoque.PALAVRAS-CHAVE: Amazonas, Cichlidae, peixe ornamental, reprodução de peixes. The aim if the present work is to supply basic information that may help the management of ornamental fishes in the Amanã Sustainable Reserve, State of Amazonas, Brazi. A study of the reproductive biology of Heros efasciatus, a cichlid fish with ornamental potential, was performed using specimens collected bi-monthly between February 2006 and January 2007 in ten creeks contributing to Lakes Amanã and Urini. The sample collection gear included hand net, seine and traps. In addition, artificial tree branches were used for sampling near the lakes. A total of 140 specimens of H. efasciatus were captured, which corresponded to only 0.07% of all specimens collected. Of this total, 50 were male, 42 were female, and 46 individuals could not be sexed due to their small size. The type of growth founded was isometric; with individuals' sizes varying from 14 mm to 174 mm. Average fecundity was estimated at 2,502 oocytes. The results of this study will help in implementing several sustainable management measures, such as establishing a minimum size for capture (higher than 97 mm) and imposing a no-fishing restriction during the spawning season of this species (from October till January). To ensure stock continuity due to the low density and low fecundity of H. efasciatus, we suggest that exploitation of this species for ornamental trade be kept to a small number of individuals per year. Reproductive biology...

Length‐weight relationships (LWRs) were estimated for 16 ornamental fish species from Amanã Lake and nine tributary streams, in Central Brazilian Amazonia. Sampling was carried out bimonthly for a year (2007–2008), using two sets of four gillnets (20 m × 2 m, 2,5; 3,5; 04; 4,5 cm stretch mesh size); trawls were performed with seine nets (35 m × 6 m, 3 mm stretch mesh size); native fish‐traps (fyke‐net like fish‐traps woven from local lianas), and dip nets (0.5 m × 0.5 m stretch mesh size). Measurements were done for standard length (SL – 0.1 cm precision) and total weight (Wt – 0.01 g precision). This study provides information on the length–weight relationships for all sampled species and, in addition, provides new maximum standard lengths for six species.

We describe the most important reproductive aspects of the flag cichlid Mesonauta insignis in the floodplain (várzea) lakes of the Central Brazilian Amazon. Between September 2005 and August 2006, fish were collected monthly from mattresses of aquatic macrophytes. Biometric measurements as well as macroscopic and microscopic analyses of the gonads were performed. Standard body lengths ranged from 2.4 to 9.3 cm, and weight−length relationships were indicative of isometric growth patterns. Reproduction events were detected in all months, but the gonadosomatic index indicated a reproductive season from October to February (during low and rising water periods), reaching a reproductive peak in February. Average fecundity was 1184 ± 40.82 (mean ± SD) mature oocytes. M. insignis exhibits an asynchronous oocytal development, characteristic of multiple spawnings. Morphological and histological analyses indicated 5 gonadal maturation stages for females. Average standard length at first sexual maturation was 5.18 cm for females and 5.5 cm for males. M. insignis shows late sexual maturation. Taken together, these aspects suggest that a life history strategy of 'equilibrium' predominates in the species; consequently, M. insignis can be considered vulnerable to high extraction rates, and can only be exploited sustainably if adequate precautionary management procedures are adopted. Some management measures are suggested for the exploitation of this species in the Central Amazon.