Ecologia da pesca e biologia reprodutiva do acará-disco (Symphysodon aequifasciatus, Pellegrin 1904) (Perciformes: Cichilidae) na RDS Piagaçu-Purus, Amazônia Central: subsídios para o manejo sustentável de um recurso natural
Historically ornamental fish have been commercially exploited in the Amazon. Nevertheless this exploitation has been carried out without much planning with little attention to the vulnerability of the fish population or to the social economical aspects of the activity for the local fishermen. Amo...
| Autor principal: | Cardoso, Felipe Rossoni |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/11225 http://lattes.cnpq.br/3106860463499551 |
| Resumo: |
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Historically ornamental fish have been commercially exploited in the
Amazon. Nevertheless this exploitation has been carried out without much
planning with little attention to the vulnerability of the fish population or to the
social economical aspects of the activity for the local fishermen. Among the
most known ornamental fish species commercially used is the discus fish
(Symphysodon spp.) but very little is known about its biology and ecology. The
little information available about this species comes from individuals raised in
captivity. This study aimed: a) describe the fishing of discus (Symphysodon
aequifasciatus, Cichlidae Pellegrin, 1904), b) determine the abundance and
colonization rate through artificial fishing atractors commonly used by local
fishermen, c) estimate size at first reproduction, fecundity, sex ratio to develop a
management plan for rational commercial use of the species. I also evaluated
the efficiency of underwater auditory methods to estimate presence and
abundance of discus and the impact of the cutting of the branches on the
riparian plant species (“araçá”, Eugenia sp.) used as fish atractors in the water.
This study was carried out in three areas of the Sustainable Development
Reserve Piagaçu-Purus (SDR-PP) in the dry season from September to
November in 2006 and 2007.
This study revealed that the fishing of discus occurs in very low intensity
and contributes little to the local economy at the SDR-PP and it uses very
artesanal forms of capturing, storage and transport. Fishing atractors showed
high efficiency as capturing grounds for discus and other commercially
important fish species. S. aequifasciatus was the most abundant species
representing more than 50% of all cichlids found in the attractors. Mean
fecundity was 1.490 eggs (± 304 SD), and population sex ratio was 1:1.
Estimated L 50 (body size at which 50% of the population is mature) was 98,4mm
(0,38 SD) and 95,8mm (0,86 SD) for females and males respectively.
Underwater auditory estimates of discus abundance by the local fishermen
predicted the number of discus in the attractors with more than 75% accuracy.
Ninety eight percent of the individuals of Eugenia sp. which branches were cut
to serve as fish attractors for discus showed regeneration indicating that the
impact on this plant species is neglectable. The biological information allied to
the local ecological knowledge and understanding of the social aspects involved
in the exploitation of discus generated by this study will be incorporated in the
management plan for the species. |