Large-scale dispersal patterns and habitat use of plains topminnowFundulus sciadicus: implications for species conservation

Abstract

Movement behaviors attributed to spawning, dispersal, or altered habitat availability are essential to the ecology of many lotic fishes and, although considerable research has described movements of sport fish, little is known about the movement patterns of nongame species. Streams and rivers, wherein plains topminnow Fundulus sciadicus are prevalent, occur in a nonequilibrium state in which habitat patches are sporadically created and lost due to hydrologic variability. This results in regular extirpation and need for recolonization of many plains fishes, including plains topminnow. Species persistence, therefore, is dependent on tolerances to fluctuating habitat conditions and life-history traits that allow dispersal over large areas. To better understand the regional distribution of plains topminnow, we monitored large-scale dispersal patterns and habitat use of two introduced populations in Nebraska. In 2011 and 2012, plains topminnow were marked using visible implanted elastomer (VIE) marks and released at the center of two 3000-m study reaches. Populations were sampled monthly from April to November in 2011 and April through September in 2012 to describe movement patterns and habitat use. Plains topminnow were highly mobile, consistently associated with select habitat features, and the estimated individual home range exceeded standard sampling reach distances by nearly four times. The movement of plains topminnow occurred at greater rates and to distances further than known for similar species. These large-scale movements likely help maintain connectivity among populations within stream drainages and facilitate recolonization of regularly extirpated habitat patches. In this context, species movement may be critical to the maintenance and potential recovery of populations of this and other rare lotic fishes.

Swimming and jumping ability of 10 Great Plains fish species

“…An effort to identify differences in swimming and jumping ability within a species that reside in variable water velocities has not been conducted. Although our results showed no significant differences between lotic and lentic topminnow, it should be noted that topminnow are backwater specialists and seek low flow areas even within a lotic system (Schumann et al 2014). Ideally, another candidate species could be assessed to investigate variability in swimming or jumping performance associated with this microhabitat selection.…”

Experimental analysis of reintroduction strategies to conserve the vulnerable plains topminnow Fundulus sciadicus in Nebraska

“…Like other opportunistic species, plains topminnow have life history traits that facilitate widespread dispersal, and their populations can increase rapidly in suitable habitats (Kinney & Lynch 1991, Winemiller & Rose 1992, Schumann et al 2012, 2015b. In just 2 yr, we were able to demonstrate that reproduction had occurred at 35% of reintroduction sites.…”

“…The persistence of plains topminnow at reintroduction sites through multiple generations despite high mortality rates suggests that reproduction has widely occurred. At sites where plains topminnow did not persist, it is possible that critical habitat for this species is no longer available; however, mobile individuals may seek and occupy suitable habitat elsewhere (Schumann et al 2015b).…”

“…reintroduction site) as 40 times the mean stream width (range: 150 to 300 m), based on measurements at 5 random points (Patton et al 2000). No sampling was conducted outside of the reintroduction site; however, dispersal of plains topminnow away from reintroduction sites has been previously described (Schumann et al 2015b). …”

Food habits of imperiled Plains Topminnow and diet overlap with invasive Western Mosquitofish in the Central Great Plains

“…Gastropods are an important diet item for both lentic and lotic populations of Plains Topminnow and are associated with heavily vegetated backwater areas, the preferred habitat of Plains Topminnow (Schumann et al 2015 a ). This affinity for prey in preferred habitat indicates the importance of habitat availability when developing management strategies and recovery plans.…”