What happens when two endangered species of fishes living in close proximity come into conflict?
This is the subject of a study by Lehigh University researchers Jennifer Gumm, Jennifer Snekser and Murray Itzkowitz published in the most recent issue of the journal Biology Letters.
The authors studied the Leon Springs pupfish (Cyprinodon bovinus) and the Pecos gambusia (Gambusia nobilis), both of which are endangered species found living together in Texas, in an attempt to understand the interactions between the two species.
The authors first estimated the population size of the pupfish over a period of seven years by counting territorial males present on the breeding shelf at the study site; they next studied the interactions between the pupfish and the gambusia by analyzing photographs of the breeding males taken in situ.
Gambusia affinis. Picture kindly supplied by David Schleser.
The authors found that the number of territorial male pupfish were declining over the period that they were studied, decreasing their efficacy at defending against intruding gambusia and consequently suffer increased egg predation or complete spawning failure.
The authors propose that artificially increasing the breeding ground area may be one way to solve theis conflict between the two endangered species.
Male pupfishes ...may disperse and escape interrupted spawnings andegg predation associated with high concentrations of gambusia.
Cyprinodon bovinus. Picture kindly supplied by the Texas Parks and Wildlife Department.
Habitat restoration may also increase population size by altering the expression of phenotypes via further decreasing competition among males, resulting in more territorial males and increased spawning rates typically associated with high-quality territories.
For more information, see the paper: Gumm, JM, JL Snekser and Murray Itzkowitz (2008) Conservation and conflict between endangered desert fishes. Biology Letters 4, pp. 655"658.