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The guppy as a conservation model: Implications of parasitism and inbreeding for reintroduction success

Van Oosterhout, Cock; Smith, Alan M.; Hänfling, Bernd; Ramnarine, Indar W.; Mohammed, Ryan S.; Cable, Joanne


Cock Van Oosterhout

Alan M. Smith

Bernd Hänfling

Indar W. Ramnarine

Ryan S. Mohammed

Joanne Cable


Ex situ conservation is of increasing importance to prevent the extinction of endangered animals in the wild. Despite low success rates of reintroduction programs few researchers have investigated empirically the efficacy of captive breeding regimes for the release of captive-bred vertebrates. We used guppies (Poecilia reticulata) from two populations in Trinidad to compare different conservation breeding regimes. The upper Aripo population was chosen for its small effective population size (Ne≈ 100) and genetic isolation, which makes it representative of many endangered natural populations. By contrast, the lower Aripo population is a genetically diverse, much larger population (Ne≈ 2400). We examined three captive-breeding regimes: (1) inbreeding fish crossed with their full siblings, (2) minimized inbreeding, no consanguineous matings, and (3) control fish crossed at random. We kept pedigree records for all regimes so that we could calculate inbreeding coefficients over four generations. The body size and fertility of guppies was significantly reduced due to inbreeding depression. The genetic load of sterile equivalents was particularly high for the lower Aripo population. Body size also declined due to breeding conditions in the captive environment. After four generations in captivity, the fish were released into a mesocosm in Trinidad. Captive-bred guppies were extremely susceptible to gyrodactylid parasites (58% survival rate) compared with their wild counterparts (96% survival). A reduced level of immunogenetic variation due to inbreeding and lack of exposure to natural parasites may have rendered captive-bred individuals more prone to infectious disease. The threat of disease outbreak is particularly high when naive captive-bred hosts are released in wild populations. Susceptible, captive-bred hosts could facilitate the transmission of parasites throughout the wild population, thus initiating an epidemic. This risk could potentially be reduced by prior exposure to parasites before release and gradual release of captive-bred individuals. © 2007 Society for Conservation Biology.


Van Oosterhout, C., Smith, A. M., Hänfling, B., Ramnarine, I. W., Mohammed, R. S., & Cable, J. (2007). The guppy as a conservation model: Implications of parasitism and inbreeding for reintroduction success. Conservation Biology, 21(6), 1573-1583.

Journal Article Type Article
Acceptance Date Jul 2, 2007
Online Publication Date Nov 7, 2007
Publication Date 2007-12
Print ISSN 0888-8892
Electronic ISSN 1523-1739
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 21
Issue 6
Pages 1573-1583
Public URL