Food habits were examined for the spottail shiner, Notropis hudsonius, in Indiana waters of Lake Michigan from June to October, 1973. Insects were the primary volumetric component of the diet. Chironomus spp. larvae and chironomidae pupae were the most important insect food items consumed. The most important zooplankton organism consumed was the benthic cladoceran Eurycercus lamellatus. Alewife, Alosa pseudoharenqus, eggs were the only other significant food consumed.A monthly comparison of food items taken by spottails showed that Chironomus spp. larvae was an important food item in all months and the primary item in September and October. Chironomidae pupae were important from June through September with greatest percent volume consumed in July, The cladoceran, Eurycercus lamellatus was an important food from July through September, reaching its highest percent volume of the diet in August. Alewife eggs were the major food of spottails in June but were also important in July.Young-of-the-year spottails fed primarily on zooplankton for the first month of their existence, but their diet changed in succeeding months and was similar to that of the adults.Analysis of competition between spottail shiners, yellow perch and alewives revealed important overlap in food items in June, August, September and October. Competition in June was between spottail shiners and yellow perch (100-250 mm) for alewife eggs. In August, the spottail shiner and alewife (140-220 mm) competed for chironomids and the spottail shiner and yellow perch competed for Eurycercus lamellatus. September competition was between spottail shiner and yellow perch (26-100 mm) for chironomids and between yellow perch (26-100 mm) and alewives (140-220 mm) for alewife larvae. Finally, in October, major competition was between yellow perch (100-250 mm) and alewives (140- 220 mm) for alewife larvae.Ball State UniversityMuncie, IN 47306

Trout-perch, Percopsis omiscomaycus, were collected during the sample months June through September, 1973, in southern near-shore waters of Lake Michigan near Michigan City, Indiana. Three transects were sampled at depths of 1, 5 and 15 m using an otter trawl and a nylon bag seine. Fish were collected mainly at midnight because of diurnal migration and feeding demonstrated by trout-perch.Food habit analysis showed Chironomus spp. and Pontoporeia affinis to be the major food items of the trout-perch. Other organisms of lesser importance as food include: Eurycercus lamellatus, Eurytemora affinis, Chironomid pupae and alewife eggs, Alosa pseudoharengus.A combined monthly analysis of trout-perch food habits showed zooplankton and alewife eggs as important food items in, June decreasing.in importance throughout the remaining sample months. Amphipoda, primarily Pontoporeia affinis, was of greatest importance in June decreasing in percent volume in July and August and increasing in volume again during the September sample period. Chironomid larvae, primarily Chironomus spp., was a minor food source in June increasing to major proportions during the remaining sample months.Monthly food habits comparing size groups showed -greatest utilization of zooplankton as a food source by Group 1 (20 - 49 mm) trout-perch during the sample period June; decreasing as trout-perch size increased. There was a marked decrease in zooplankton consumption in the remaining sample months for combined size groups.Monthly food habits comparing size groups showed the greatest utilization of Amphipoda during the June sample month. Size Group III (100 - 139 mm) trout-perch consumed Amphipoda in largest quantities throughout the combined study period.Monthly food habits for Insecta consumption comparing size groups were at lowest volume in June, increasing in volume during the remaining sample months. Chironomus spp. was the major food item consumed by trout-perch.Ball State UniversityMuncie, IN 47306

Ball State University LibrariesLibrary services and resources for knowledge buildingMasters ThesesThere is no abstract available for this thesis.

Yellow perch, Perca flavescens (Mitchill), were collected by trawling and gillnetting in Indiana waters of Lake Michigan near Michigan City, Indiana. Sampling was conducted during the months of June, July and August from 1984 through 1986.Growth rates and length-weight relationships were found to be considerably lower than those reported previously. Males declined 38 mm at age I, 55 mm at age II, 56 mm at age III and 35 mm at age IV comparing 1986 to 1976. Females showed similar declines for the same period at 40 mm for age I, 58 mm at age II, 66 mm at age III and 53 mm at age IV. The primary reason for the decrease in growth appears to be due to the current high population density of yellow perch in Indiana waters of Lake Michigan.Maturation of males for 1986 appears to be slower than that of 1984. All male perch were mature by age III in 1984. However, only 68x of the males were mature at the same age in 1986. In 1984, 94% of the females were mature by age IV while 86% were mature at the same age in 1986.Differences in maturation rate may be a reflection of the reduced growth rates. Size at maturity was found to be similar for both sexes in 1984 and 1986. All females were mature by 230-239 mm in 1984 and 220-229 mm in 1986. All male perch were mature at 180-189 mm in 1984 and 220-229 mm in 1986.Total estimated average annual percent mortalities of 79, 58, 66 and 55 were calculated for combined sexes from age composition analyses end trawl catch data for 1976 and 1984-86. Yellow perch production for 100 fish was estimated for June through August using the Allen curve method. Biomass of substock ( <130 mm), stock ( >129 mm) and quality fish (200 mm or larger) were estimated using Proportional Stock Density to investigate population structure. The Allen curve biomass models were modified to more accurately reflect the trawl catch density data as an index of population changes in 1976 compared to 1984-86. Theoretical biomass for the substock component increased 23 fold from 1976 to 1986. Biomass of the stock sized fish was estimated as 15 times greater in 1986 compared to 1976. Quality fish biomass varied from year to year with the average for 1984-86 estimated as 14 times greater than 1976. The most apparent factor now influencing deterioration of growth and resultant quality of the population is decreased mortality/increased survival with increase in biomass. If the low mortality rates observed for 1984-86 remain unchanged, the data indicate continued population density increases will result in even lower growth rates, and a population dominated by a higher percentage of small, non-quality fish.Food habit analyses for 1984 were compared to a diet study of yellow perch in 1972 for the study area. Zooplankton increased from 0.4x in 1972 to 9% of the volume in 1984 for 100-175 mm perch. This trend may reflect an increase in zooplankton populations in response to the population decline of the planktivorous alewife. Young-of-the-year yellow perch made up 85% of the stomach volume for 176-225 mm perch in 1984 while none were found in samples for 1972. This clearly shows yellow perch are resorting to cannibalism resulting from excessive intraspecific competition.Diet analyses by month revealed alewife eggs were moat important during peak abundance in June and July. Yellow perch (YOY) and Pontocoreia affinis became important during August. Analysis by size interval showed zooplankton and insects (primarily Chironomidae) were important to the diet of perch in the 30-59 mm (YOY) size interval. Copepoda were important by percent volume until approximately 60 mm when the zooplankton component switched to Cladocera. Data for 60-119 mm (age I+) fish indicates alewife eggs were important during June but insects became increasingly more important during July and August. Diversity in food items consumed diminished with increase in size as diet of 120-159 mm (age II+) yellow perch consisted largely of fish. Increases in percent volume of rainbow smelt in June and July, and Y0Y perch in August for age II+ and older perch compared to younger/smaller fish may be related to increased capture success. Diet of fish larger than 160 mm (age III+ and older) consisted almost entirely of rainbow smelt and Y0Y yellow perch.Ball State UniversityMuncie, IN 47306

There is no abstract available for this thesis. / Department of Biology

The yellow perch, (Perca flavescens), is an important commercial and sport fish in Indiana waters of Lake Michigan. The population is currently managed by temporary restrictions of commercial harvest. A computer simulation model was developed to examine the effects of various constant harvest quotas and alewife densities on yellow perch relative numbers.Model design is based on the SLAM II simulation language incorporating a FORTRAN biological subroutine. The age-structured population model includes measured or predicted biological characteristics of the dynamic pool model. Recruitment is based on a preestablished three-dimensional Ricker stock-recruitment function including alewife (Alosa pseudoharengus) species interaction as a constant or stochastic factor. Sex-specific natural mortality rates were established through life history parameter analysis and the von Bertalanffy growth factors. Density-dependent growth is incorporated into each year of a model run and fluctuates with the simultaneous density of fish. Constant levels of commercial harvest ranging from 0 to 700,000 kg were used in 20-year forecasts. Initial conditions for model runs were 1984 and 1994 trawl CPUE levels when yellow perch were at high and low levels, respectively according to standardized sampling. Response variables were examined as mean catches over each forecast length and included: age 2 fish, spawning stock (z 190 mm), and total catch > age 1.Alewife densities had a tremendous impact on mean catches of the response variables. Highest catches under any forecast period occurred when alewife was considered absent from the system. Catches declined as alewife density was increased as a 20-year constant under each harvest regimen.Catches of spawning size fish were maintained at highest levels for all forecast periods when harvest was set to zero. Catches of young fish were moderate with this harvest regimen if initial catch conditions were high such as in 1984. Catches of young fish were always higher in the absence of a commercial fishery if initial catch conditions were low such as in 1994. Low to moderate harvest quotas could maintain moderate levels of young fish for the forecast length if initial model conditions were high. However, these quota levels for the 1984-2004 forecast length resulted in lower mean catches of spawning size fish as compared to the no commercial fishery regimen. The best case scenario for all response variables when initial catch conditions were low was under a no commercial harvest regimen. / Department of Biology