D. J. Renfro

Otoliths from 822 trophy (>4.5 kg) largemouth bass (Micropterus salmoides) caught by anglers in Florida were obtained from taxidermists during 1987-1993. The fish were harvested from 211 different water bodies. Longevity and mean growth exceeded those reported previously in Florida. Mean age of trophy largemouth bass statewide was 9.7 years and ranged from 4.0 to 16.5 years. Mean growth averaged 0.54 kg/year with a range of 0.28-1.27 kg/year. Growth rate of trophy largemouth bass increased from north to south Florida. Accelerated growth, longevity and strong year classes were important...

This study describes a method of constructing inexpensive, durable, shallow-water reefs in freshwater lakes with whole Australian pines (Casuarina spp.). Snorkel observations demonstrated that largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), and redear sunfish (L. microlophus) abundance was significantly higher on reef areas as compared to between-reef areas, or control areas. A creel survey measured improved catch rates for largemouth bass and lower catch rates for sunfish on reef areas. The use of on-site materials during lake construction should be considered an...

Growth rates for the 1980 year class of black crappie were determined from samples collected in the St. Johns River, Florida, 1981 through 1987. Actual mean lengths of groups of black crappie aged by otolith evaluation were compared to back calculated lengths from otoliths of black crappie collected each year. Differences in actual and back calculated lengths for black crappie collected were not significant (P > 0.05). Coefficient of determination values (r2) dropped rapidly as differential growth rates increased. Overall, back calculated lengths for age I and II black crappie increased...

Two types of commercial wire catfish traps were fished in lakes Dora and Eustis between January and May 1984. Catches at shoreline and offshore fishing sites were evaluated for both trap types. Door throat traps harvested 4.1 catfish, 0.6 game fish, and 0.1 non-game fish per trap day. Open throat traps harvested 0.8 catfish, 0.6 game fish, and 0.2 non-game fish per day. Door throat traps were 5.7 times more efficient at harvesting catfish than open throat traps. Overall, shoreline fishing sites yielded more fish (catfish, game fish, and non-game fish) than offshore sites. Initial mortality...

A 3-year tagging study was conducted to determine movement and distribution of catfish in the St. Johns River, Florida. A total of 8,800 white catfish (lctalurus catus), channel catfish (I. punctatus), brown bullhead (I. nebulosus) and yellow bullhead (I. natalis) were tagged with Floy FD-68B anchor tags from May 1983 through December 1985. Of these tagged fish, 1,227 (13.9%) were recaptured. The highest return was from lake habitat (22.8%) followed by riverine (17.1 %) and tributary (7.0%) habitats. The longest distance travelled was 178.2 kIn upstream. Approximately 52.0% of the...

Eighteen hundred and thirty-four black crappie (Pomoxis nigromaculatus) were collected from the St. Johns River, Florida, in late winter and early spring, 1982 to 1985. Differences in numbers and growth rates of males and females collected were not significant (P > 0.05). Fish were separated into age groups using length-frequency distributions and by counting annuli on otoliths. Only 2 distinct age groups were discernible by length-frequency analysis, whereas 6 to 8 groups were identified by otolith aging. Mean lengths of age groups obtained from lengthfrequency were overestimated 3 of...

Twenty-one brown bullhead (Ictalurus nebulosus), 25 channel catfish (I. punctatus) and 25 white catfish (I. catus) collected by fish trap were aged by counting annuli from the articulating process (AP), basal recess (BR) and mid-spine (MS) sections of pectoral spines. Five large channel catfish collected from hoop nets were also aged using spine techniques. Attempts were also made to age catfish by counting opaque bands or checks from whole sagittal otoliths and otolith longitudinal and cross sections. Annuli were visible in all pectoral spine sections. Fish older than 3 years showed some...

The retention of Floy FD-68B anchor tags and survival of 200 tagged and fin-clipped white catfish (Ictalurus catus) and channel catfish (Ictalurus punctatus) were determined over a 184-day period in 2 0.20-ha ponds. In 1 pond, 50 tagged fish and 50 fin-clipped fish were stocked. In the second pond, 50 tagged and fin-clipped fish and 50 fin-clipped fish were stocked. Of the 70 tagged fish recovered (all tagged fish received 2 tags), all had retained at least 1 tag. Four Floy tags were lost, yielding an overall tag retention of 97.1 %. No separation of plastic sleeves was observed from the...

From December 1981 through March 1983, 71 observations of pound nets were conducted. In 407 net days, commercially important species comprised 93.5% of the total pound net catch while game fish species comprised 4.4%. An average of 1.8 game fish were caught per net day. Harvestable-size game fish (that size retained by sport fishermen) represented 3.6% of the total catch and comprised 81.5% of all sizes of game fish caught. Initial mortality was 3.3% for game fish or 0.06 game fish deaths/ net day. An estimated 68 game fish/km of shoreline/year were caught by the entire pound net fishery...