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Vol. 44 No. 4, 2005
Do Eastern Mosquitofish Exhibit Anti-predator Behavior towards Red Swamp Crayfish?
Emília Pereira Leite1, Pedro Manuel Anastácio3, Margarida Ferreira2, Luís Vicente2, and Alexandra Marçal Correia1,*
1Universidade
de Lisboa, Museu Nacional de História Natural, Departamento de Zoologia
e Antropologia (Museu Bocage), Centro de Biologia Ambiental (CBA), R.
Escola Politécnica, 58, 1269-102 Lisbon, Portugal
2Universidade
de Lisboa, Faculdade de Ciências, Departamento de Biologia Animal,
Centro de Biologia Ambiental (CBA), Campo Grande, P-1749-016 Lisbon,
Portugal
3Institute of Marine Research (IMAR),
c/o Departamento de Ecologia, Universidade de Evora, R. Romão Ramalho,
59, 7000-671 Évora, Portugal
Emília Pereira Leite, Pedro Manuel Anastácio, Margarida Ferreira, Luís Vicente, and Alexandra Marçal Correia (2005)
Anti-predator behavior has been described in many freshwater fish
species. Freshwater crayfish may have a great impact on prey species
through behavioral changes. The eastern mosquitofish, Gambusia holbrooki, and the red swamp crayfish, Procambarus clarkii,
are native to North America, and have been introduced worldwide,
causing negative effects on aquatic ecosystems. The interactions
between these exotic species are poorly known. In natural habitats P. clarkii consumes G. holbrooki,
but it is not clear if the mosquitofish has anti-predator defenses
against the crayfish. The main objective of this study was to determine
if G. holbrooki exhibits anti-predator behavior in the presence of P. clarkii.
To address this question, laboratory tests were performed in
experimental aquaria, analyzing the following behavioral traits of the
mosquitofish: activity, distance from the predator, and space use. The
mosquitofish were generally active and mainly preferred open space in
both controls and treatments. Results suggest that G. holbrooki does not display anti-predator behavior when exposed to P. clarkii under the laboratory conditions used in this study.
Key words: Predator avoidance, Gambusia holbrooki, Procambarus clarkii, Activity, Space use.
*Correspondence: Tel: 351-21-3965853. Fax: 351-21-3969784. E-mail: amcorreia@fc.ul.pt
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