How do Iowa Darters reproduce?

     Iowa darters reach sexual maturity at about the age of 1 year (Copes 1986).  They are considered to be “early spawners”. Some Iowa darters may begin to reproduce as early as late April/early May and may continue to spawn well into the month of July.  Typically however, their period of spawning is May-June (Eddy et al. 1974).  During the spawning season, the pigmentation of the male fish changes colors.  Darters of this species usually feature 9-12 dark bands/spots on their sides.  However, when spawning, the coloration changes to a bright greenish, bluish and their 10 red spots in-between the green bands become brighter as well to attract females.  Males of many different species of animals, such as birds, exhibit this quality.  Bright, flashy colors represent good health. (Eddy et al. 1974). The actual process of spawning is quite interesting.  The male will search for an area and establish his territory.  He will defend this area from all other males of his species.  When a female, ready to reproduce, enters his territory, he will swim circles around her until she stops on the vegetation, sand or roots.  The male then continues to mount the female, they both vibrate, the female’s eggs are released and the male fertilizes them.  The eggs then attach to the vegetation (Copes 1986).



Figure 1. Male darter breeding coloration.

Figure 2. Female darter coloration.



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