This study was undertaken to quantify the length-fecundity and length-egg size relationships for yellow perch Perca flavescens in the Indiana waters of Lake Michigan. Data were pooled from gill-net collections made in 1985, 1986, and 1999, resulting in a wide length range of mature female yellow perch (172-332 mm total length [TL]). The length-fecundity relationship was log 10 F ϭ Ϫ3.220 ϩ 3.223·log 10 TL (r 2 ϭ 0.89), where F is fecundity. The mean preserved egg volume (V; mL) increased with yellow perch TL and was represented by the following equation: log 10 V ϭ Ϫ2.06 ϩ 1.10·log 10 TL (r 2 ϭ 0.48). These results reveal that larger females produced both more and larger eggs than did smaller females. Therefore, the intense harvest targeting large yellow perch (primarily females) in the 1980s and 1990s may have had an effect on the quantity and quality of eggs spawned by the population, possibly resulting in reduced recruitment.

Externally visible injected marks provide valuable information to scientists, but their presence may increase an individual's susceptibility to predation. In a laboratory experiment, we evaluated the feeding preferences of rock bass (Ambloplites rupestris) and smallmouth bass (Micropterus dolomieu) for unmarked, green-VTE-marked, and yellow-VIEmarked fantail darters (Etheostomaflabellare). Although neither predator exhibited significant selectivity for a particular treatment (ANOVA, p>0.05), smallmouth bass appeared to prefer green-marked over control or yellow-marked darters. Contrasting die1 feeding strategies may explain these preferences. In a marldrecapture field study, we examined the influences of mark color and mark location on predation rate by examining variation in darter recapture rates. Again, no significant differences were detected among treatments (ANOVA, p>0.05), but dorsal-marked darters had slightly lower recapture rates than did ventral-marked ones. The effects of mark color were insignificant and opposite to those found in the laboratory study, indicating that experimental preference may not equate to increased predation rate in the wild.

<em>Abstract.</em>—Black bass <em> Micropterus </em>spp. are important components of river fisheries in the southeastern U.S., but little is known about their basic life history and population characteristics in these systems. Largemouth Bass <em> M. salmoides </em>and Shoal Bass <em> M. cataractae </em>were collected from three areas in the Flint River on multiple occasions from 2005 through 2013. Collections were taken from the undammed section of the Flint River above Lake Blackshear, within Lake Blackshear, and the regulated reach of river below Lake Blackshear. Shoal Bass do not occur in Lake Blackshear, so only Largemouth Bass were collected. Population and life history data such as body condition, growth, mortality, and recruitment variability were examined for these species in all three areas. Shoal Bass and Largemouth Bass appeared to have similar scopes of growth in this system, reaching similar maximum sizes. However, Largemouth Bass grew slower than Shoal Bass in both river sections. Growth of both species was slower in the upper versus lower area of the river; growth of Largemouth Bass was similar between the lower Flint River and Lake Blackshear. Female Largemouth Bass grew faster than males in both sections of the river; whereas, growth of Shoal Bass was similar between sexes. Longevity of Largemouth Bass appeared to be slightly higher than Shoal Bass, with correspondingly lower annual mortality. Age frequencies and annual mortality was similar between the sexes for both species in all areas. Recruitment of Largemouth Bass was negatively affected by high flows in the spring in the upper Flint River and Lake Blackshear; whereas, Shoal Bass recruitment in the upper Flint River was not correlated to any flow measure. The opposite pattern was found in the lower Flint River, with recruitment of Largemouth Bass unaffected by flow but Shoal Bass recruitment negatively affected by high flows. Shoal Bass exhibited numerous differences from Largemouth Bass in the Flint River, including growth, mortality, and recruitment, demonstrating the danger in applying rate function data or basic biology concepts from one species to another closely related one. Results from this study will help biologists better understand the potential and limitations of black bass fisheries in rivers, and thereby enable more effective management.