Spawning Ecology of the Critically Endangered Moapa Dace Revealed Through Underwater Videography

Moapa dace, Moapa coriacea, are an endangered cyprinid endemic to warm springs of southeastern Nevada.  This species was federally listed because of its limited range, low abundance, and impacts from introduced species.  Spawning by Moapa dace has never been documented.  Further knowledge of its spawning ecology will be important for identifying factors that induce spawning in captivity and will provide vital data for managers to utilize in habitat improvement projects.  We installed twelve underwater cameras equipped with infrared light to record both day and night activity.  Camera sites represented a variety of habitat-types (i.e. pools, glides, runs, and riffles).  We quantified available habitat by dividing the field of view in front of each camera into a grid.  Then we assessed dominant size and embeddedness of substrate, depth, and stream velocity in each grid-block.  We recorded approximately 21,000 hours of video from March through May 2012.  We randomly selected sixteen ten-minute video clips in every 24-hour period, from each camera, to analyze for spawning activity.  Based on activity reviewed to date, Moapa dace appear to be broadcast spawners.  Spawning events were recorded in three sites; one in a run, four in a glide, and five in a pool.