Utilize este identificador para referenciar este registo: http://hdl.handle.net/10348/4332
Título: Life history, population dynamics and production of eastern mosquitofish, Gambusia holbrooki (Pisces, Poeciliidae), in rice fields of the Lower Mondego River Valley, West Portugal.
Autor: Cabral, João Alexandre
Marques, João Carlos
Palavras-chave: Mosquitofish
Gambusia holbrooki
Poeciliidae
Growth
Reproduction
Population dynamics
Production
Data: 1999
Citação: Cabral J. A. and Marques J. C., 1999
Relatório da Série N.º: 20;6
Resumo: The introduced population of Gambusia holbrooki from the rice fields of the lower Mondego River Valley, Portugal, was studied for 15 months, relating their life cycle and population dynamics with its production, in order to assess the role of the species in the energy flow and secondary production in this type of agro-ecosystem. Two main annual cohorts (1995 and 1996 cohorts) were identified. The females outnumbered males and the average female/male-ratio was 4. The inspection of ovary developmental stages of this viviparous fish, revealed that the most important reproductive period was between April and August. The first recruits were recorded in June and were present thereafter until October. Males from the parental cohort died before August, whereas parental females could survive until October. Mean adjusted fecundity (number of embryos divided by female standard length) peaked in July 1996 (0.95) and in June 1997 (1.05). Females reached greater sizes, had a higher growth rate and lived longer than males. Annual production was estimated at 3.101 g×m–2×year–1 (ash-free dry weight, AFDW), the average biomass at 2.896 g×m–2 (AFDW), and the P/B ratio was 1.071. A conjugation of life history, population dynamics, production and ecological traits (e.g. fast growth, reduced longevity, viviparity, high productivity, an intermediate position in food chain, and no special habitat requirements for reproduction) clearly show that the populations of G. holbrooki, introduced into rice fields all over the world, may play an important role in the structure and functioning of the biological communities of these important agro-ecosystems.
Revisão por Pares: yes
URI: http://hdl.handle.net/10348/4332
Tipo de Documento: Artigo
Aparece nas colecções:DEBA - Artigo publicado em Revista Científica Indexada

Ficheiros deste registo:
Ficheiro Descrição TamanhoFormato 
7. Cabral and Marques 1999.pdf
  Restricted Access
431,43 kBAdobe PDFVer/Abrir Solicitar cópia


FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex mendeley Endnote Logotipo do DeGóis Logotipo do Orcid 

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.