Growth of Hybrid Sunfishes and Channel Catfish at Low Temperatures

The growth of hybrid sunfish (male bluegill, Lepomis macrochirus x female green sunfish, L. cyanellus) and channel catfish (Ictalurus puncrates) below 15 C was determined in ponds on natural food and in cages on artificial feed. In all cases, the hybrids gained weight, while the channel catfish lost weight

A White Paper on the status and needs of largemouth bass culture in the North Central Region

Largemouth bass (Micropterus salmoides) are the most sought-after freshwater sport fish in the United States. Largemouth bass are a member of the family Centrarchidae. Currently the genus Micropterus contains seven species. As part of the development of the new strategic plan, the North Central Regional Aquaculture Center (NCRAC) is trying to address the concern that the long-term focus of research goals and priorities may be lost because the NCRAC Board of Directors (Board) and the Industry Advisory Council memberships change over time. The Board in the June 1999 meeting directed that an updateable white paper be written on largemouth bass. The white paper is not an exhaustive literature review, but a working document that defines the current status of largemouth bass culture including the critical factors limiting the economic production in order to make recommendations for future research. Industry participation and peer reviews are critical components for the evolution of this document

Relative Survival and Contribution of Saugers Stocked in the Peoria Pool of the Illinois River, 1990–1995

Numbers of sauger Stizostedion canadense declined in the Peoria Pool of the Illinois River from the 1970s to the 1990s. Stocking was evaluated as a means of supplementing natural reproduction in the pool. Marked fry were stocked in 1991–1994 (20–176/ha), and marked fingerlings were stocked in 1990–1995 (,1–20/ha). In 1990, fingerlings with a mean total length of 44 mm were stocked in June, and 92-mm fingerlings were stocked in September and October. Relative survival was 4.9:1 in favor of the 44-mm fingerlings. During 1991–1994, relative survival averaged 440:1 for stocked fingerlings (39–61 mm) versus fry. From 1990 to 1995, contribution of stocked saugers to the year-classes averaged 33.9% at age 0. Because of the immigration of wild saugers into Peoria Pool and emigration of stocked and wild fish to other pools, contributions of stocked saugers to individual year-classes decreased each year subsequent to stocking. Mean contribution of stocked saugers at harvestable ages (age 2 and older) was 9.1%. Total contribution of all stocked saugers after 6 years to all year-classes was 22.8%

Effects of Light on Feeding and Egestion Time of Striped Bass Fry

Fry of striped bass (Morone saxatilis) 9 to 19 days old remained active and continued to feed at night. We observed no significant difference in egestion time between fish held in light and those held in darkness. At 20°C the gastrointestinal tracts of all 15- and 19-day-old fish were emptied of marked brine shrimp in 11-12 h. None of the 9-day-old fish held at 25°C contained marked brine shrimp after 9 h

Frequency of Natural Hybridization between Saugers and Walleyes in the Peoria Pool of the Illinois River, as Determined by Morphological and Electrophoretic Criteria

External morphological characteristics and protein electrophoresis at two diagnostic loci were used to determine the proportion of 704 Stizostedion samples collected from the Peoria Pool of the Illinois River during March 1995 that were saugers S. canadense, walleyes S. vitreum, or their hybrids. Morphological analyses indicated that 616 (87.5%) fish were saugers, 58 (8.2%) were walleyes, and 30 (4.3%) were hybrids; electrophoretic analyses indicated that 625 (88.8%) fish were saugers, 50 (7.1%) were walleyes, and 29 (4.1%) were hybrids. Clear discrepancies between the morphological and electrophoretic analyses affected at least 43 (6.1%) fish. Only 2% of saugers were hybrids, but at least 14% of walleyes possessed sauger alleles. Polymorphism at the PGM-1* locus in Peoria Pool saugers was also identified. We recommend electrophoretic screening for hybrids if saugers or walleyes are collected for use as broodstock from waters where they co-occur

The Cyclic Stocking of Parentals in a Farm Pond to Produce a Population of Male Bluegill x Female Green Sunfish F\u3csub\u3e1\u3c/sub\u3e Hybrids and Male Redear Sunfish x Female Green Sunfish F\u3csub\u3e1\u3c/sub\u3e Hybrids

A population of male bluegill (Lepomis macrochirus) x female green sunfish (Lepomis cyanellus) F1 hybrids was established by parental stocking in a southern Illinois farm pond containing male redear sunfish (Lepomis microlophus) x female green sunfish F1 hybrids and largemouth bass (Micropterus salmoides). In 1967, male redear sunfish and female green sunfish parentals, along with fingerling bass, were stocked into a new farm pond. Nine years later in 1976, male bluegill and female green sunfish were stocked into the same pond. At the time of sampling in the fall of 1978, bluegill x green sunfish F1 hybrids weighed an average of 3 g at annulus I, 24 g at annulus II, and 171 g at annulus III. Growth rates among the three year classes varied widely. The best growth was exhibited by the 1976 year class of bluegill x green sunfish F1 hybrids. Redear x green sunfish F1 hybrids sampled in 1969 weighed an average of 32 g at annulus I, 118 g at annulus II, and 217 g at annulus III. Both F1 hybrid sunfish crosses produced fish that reached the theoretical minimum harvestable size of 110 g at annulus III