I've been making monthly collections of telescope shiners, Notropis telescopus, from Hurricane Creek in Jackson County, Alabama, since this past February for a study of the species' reproductive biology. I finally sat down yesterday afternoon and sorted out all of the male lengths (n=140) and all of the females (n=117) to calculate average standard length for each sex. This worked out to be 50.5 mm for females and 45.3 mm for males. I ran a 2-tailed t-test on the data testing for significance of difference, and males and females have significantly different SL with a p << .001.

That's all well and good, but I'm curious to compare it against any other N.A. cyprinids, especially Notropis species and closely related genera. I have a few species to compare this to, notably burrhead and silverstripe shiners, but I'd be grateful for any leads to others. As always, thanks!

Did you run across these yet Bruce? Ton of stuff pre-1960's, if you look at Google Scholar. Looks like some more good stuff in the references.

^^##^^##^^##

http://www.bsu.edu/web/mpyron/ssd.pdf

^^##^^##^^##

JO - Journal of Natural History
PB - Taylor & Francis
AU - Rabito, Felix G.
AU - Heins, David C.
TI - Spawning behaviour and sexual dimorphism in the North American cyprinid fish Notropis leedsi, the bannerfin shiner
SN - 0022-2933
PY - 1985
VL - 19
IS - 6
SP - 1155
EP - 1163
AB - The spawning behaviour and sexual dimorphism of the little known North American cyprinid fish, Notropis leedsi, is described based on observations made in laboratory aquaria. Notropis leedsi is a crevice spawning species, a trait characteristic of members of the subgenus Cyprinella. Males establish breeding territories through ‘mock battles’ and defend them by chasing away intruding males or, at times, through threat displays or ‘mock battles’. Although wild-caught males are significantly larger than females, sexual dimorphism is more pronounced in the colour pattern and fin size, especially the dorsal and anal fins.

The modes of spawning behaviour in the genus Notropis are reviewed. The relationship between the promiscuous mating system (polybrachygamy), the crevice spawning mode, and sexual dimorphism in N. leedsi are discussed in relation to current notions regarding sexual selection.
UR - http://www.informawo...222938500770721

^^##^^##^^##

I'm impressed, you found maybe the article we're basing our work on in large part. The bannerfin (leedsi) is now in Cyprinella, but the principles are the same for us. I'm working with three students now to learn to distinguish Early Maturing from Late Maturing from Mature from Ripe ovaries based on images we made from digital 'scopes. David Heins is my main man, I'm sure he doesn't know it yet...

Let me follow up my last post by thanking Todd for his suggestion. I should be more specific; I'm mostly interested in any data sets that typical Googlish searches wouldn't find for one reason or another.

I may have old red shiner data from the Virgin River in Nevada, not sure, that may be one of the species the crews didn't measure length, and probably didn't distinguish gender. I'll check. I also have some speckled dace, spinedace, springfish, poolfish, and desert sucker lengths from a variety of projects, but not gender specific, so I doubt if any of these would be of any help. It would be interesting to do a Length/freq and then examine some of the common fish of the larger size frequency to see if they are mostly females or males.

shawn

Intuitively I would think there would be a difference just like there is in Poeciliids (the most obvious example). Bruce what is the range and distribution like of the data? Even with that large of a sample size I could see how a T distribution might not be the best fit. Makes me curious to go back and look at all the lengths I have because I did distinguish sex and I have a whole lot more than one years worth available.

Intuitively I would think there would be a difference just like there is in Poeciliids (the most obvious example). Bruce what is the range and distribution like of the data? Even with that large of a sample size I could see how a T distribution might not be the best fit. Makes me curious to go back and look at all the lengths I have because I did distinguish sex and I have a whole lot more than one years worth available.

For the telescope shiners, we have 162 males, size range 27.26 - 56.85 mm with a mean of 45.34 mm SL, and 133 females, size range 37.34 - 65.32 mm with a mean of 50.46 mm SL. I've been running t-tests because the data are normally distributed, it's easy, and everyone knows what you're talking about with a t-test. I'm open to suggestion otherwise.