Fish ID help

[TheBluegillMaster]

thanks for the help. I think I can do a pretty decent job identifying the bigger fish, but the minnows and darters are always so difficult, with all the colors, patterns and more. Any tips with that?

 

[Fish Sticks]

thanks for the help. I think I can do a pretty decent job identifying the bigger fish, but the minnows and darters are always so difficult, with all the colors, patterns and more. Any tips with that?

Just look at lots of pics and and listen to fisheries podcasts that talk about their characteristics. Might still be a tessellated darter I am just not sure with fins collapsed and no sub orbital bar. I am not a pro either lol

 

[Mike]

You have to control for variables other than what tour looking at, observational data is dangerous to make conclusions from.

Heres a study suggesting otherwise

“To investigate whether introductions of nonnative trout affect growth and diet of nongame fish in small streams, we designed a field experiment to examine interactions between slimy sculpin Cottus cognatus and native brook trout Salvelinus fontinalis or nonnative brown trout Salmo trutta. We hypothesized that brown trout would compete with and reduce growth of slimy sculpin. We expected no change in slimy sculpin growth in treatments with brook trout because the two species co-occur in their native range and thus may have evolved methods to partition resources and decrease competitive interactions. Enclosures (1 m2) were stocked with (1) juvenile brown trout and slimy sculpin, (2) juvenile brook trout and slimy sculpin, or (3) slimy sculpin alone (control). Fish were stocked at three densities to examine intraspecific versus interspecific competition. Replicates of each treatment were placed in riffles in Valley Creek, Minnesota, and six experimental trials were conducted over three summers (2002-2004). Brown trout presence was associated with reduced growth of large slimy sculpin in enclosures, whereas brook trout presence produced no change in slimy sculpin growth; these effects did not depend on fish density. Brown trout or brook trout presence was not associated with shifts in the diets of slimy sculpin, indicating that reduced slimy sculpin growth in the presence of brown trout was not due to prey selection or prey availability changes. Our research suggests that effects on growth of slimy sculpin in Valley Creek differ between introduced brown trout and native brook trout; however, the mechanisms underlying changes in slimy sculpin growth are unclear. Although brook trout and brown trout appear to fill similar ecological roles in small, coldwater streams, brown trout may negatively impact growth of nongame fish.”

USGS Publications Warehouse

To investigate whether introductions of nonnative trout affect growth and diet of nongame fish in small streams, we designed a field experiment to examine interactions between slimy sculpin Cottus cognatus and native brook trout Salvelinus fontinalis or nonnative brown trout Salmo trutta. We...

pubs.er.usgs.gov

 

[Mike]

I wouldn’t care about other variables in a simple fisheries management (forage introduction) exercise as long as the conditions for the forage fish species seemed suitable for success. This was not an experiment; it was fisheries management. If one were to convert it into an experiment one would have needed to measure variables associated with BT diet and growth before and after the sculpin introduction and establishment of a reproducing population. Given the small life-long home range of sculpins (a square meter or two or three) and the time that it would have taken to establish a population throughout the riffles/runs in this stream section such an experiment would have likely taken at least a decade to complete. The primary, shorter trem fisheries management objective was met, which was to establish and grow a reproducing population of slimy sculpins in an effort to expand the forage base for the Class A wild BT population. Whether the BT impacted the individual sculpin growth rates didn’t matter so long as the sculpins eventually reached maturity, spawned successfully, and their population grew and you don’t need an experiment to observe that and come to a conclusion that population establishment and growth were successful despite the presence of a Class A BT population. The only assumption was, as elsewhere, that the BT would feed on them.