Steve E. Lochmann

A Comparison of Shoreline Seines with Fyke Nets for Sampling Littoral Fish Communities in Floodplain Lakes

Abstract We compared shoreline seines with fyke nets in terms of their ability to sample fish species in the littoral zone of 22 floodplain lakes of the White River, Arkansas. Lakes ranged in size from less than 0.5 to 51.0 ha. Most contained large amounts of coarse woody debris within the littoral zone, thus making seining in shallow areas difficult. We sampled large lakes (>2 ha) using three fyke nets; small lakes (<2 ha) were sampled using two fyke nets. Fyke nets were set for 24 h. Large lakes were sampled with an average of 11 seine hauls/lake and small lakes were sampled with an average of 3 seine hauls/lake, but exact shoreline seining effort varied among lakes depending on the amount of open shoreline. Fyke nets collected more fish and produced greater species richness and diversity measures than did seining. Species evenness was similar for the two gear types. Two species were unique to seine samples, whereas 13 species and 3 families were unique to fyke-net samples. Although fyke nets collected ...

Effect of Tank Stocking Density on Larval Sunshine Bass Growth and Survival to the Fingerling Stage

Abstract Determining optimum parameters for tank culture of sunshine bass (white bass Morone chrysops × striped bass M. saxatilis) fingerlings will facilitate a year-round supply of seed for the production cycle of this increasingly popular food fish. This experiment determined the relationship between the stocking density of sunshine bass larvae in tanks and their survival rate and size at the time they were trained to accept commercial feeds. Four-day posthatch (dph) larvae were stocked at 10 densities from 30 to 120 larvae/L in 10-larvae/L increments. Larvae were initially fed rotifers Brachionus plicatilis cultured with Nannochloropsis spp. algae paste and commercial rotifer feed at 60 rotifers·mL−1·d−1 until 10 dph. Conversion to brine shrimp Artemia spp. began at 7 dph. The daily ration of brine shrimp started at 4/mL and increased by 4/mL every 4 d up to 20/mL. Training to dry starter feed began at 20 dph when 6 g/d of a commercial larval starter meal was offered; 2 d later, salmon starter meal was...

Mortality of Fish Larvae Exposed to Varying Concentrations of Cyclopoid Copepods

Abstract Cyclopoid copepods can prey on freshwater fish larvae. The magnitude of predation is related to the size and concentrations of the cyclopoid copepods and the size of the fish larva; it is also likely to be specific to certain species. We studied 5-d-old larvae of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis), golden shiner Notemigonus crysoleucas, fathead minnow Pimephales promelas, and goldfish Carassius auratus in four separate experiments. Larvae were stocked at 20/L into 2 L of water containing various concentrations of the cyclopoid copepods Cyclops vernalis and Mesocyclops vericans to ascertain the effect of predation on mortality. We also compared predation rates observed in this study with rates predicted by an empirical model of crustacean predation on fish larvae from the literature. Sunshine bass alone were susceptible to predation mortality at the cyclopoid copepod concentrations used in this study. Mortality at 400 cyclopoids/L was significantly h...

Predation of Cyclopoid Copepods on Sunshine Bass Fry

Abstract Low and variable survival rates have been observed for the fry of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) in rearing ponds despite adherence to the standard procedures used to stock fry of striped bass and palmetto bass (female striped bass × male white bass). A mismatch between sunshine bass fry and forage of suitable size is regarded as the primary cause of fry mortality. Mortality could also be due to direct predation on the fry by carnivorous copepods. To test the latter hypothesis, recently hatched sunshine bass fry were exposed to a concentration gradient of cyclopoid copepods (0, 5, 50, and 500 copepods/L) during a 24-h period. No significant differences in survival rates were found among the first three treatments, but fry suffered high mortality in the 500-copepod/L treatment. Adult copepods are observed at similarly high densities in culture ponds. Results were also used to test an empirical model that predicts predation rates on fish larvae by...

Tank Culture of Sunshine Bass Fingerlings without Using Rotifers

Abstract A previously reported protocol for culture of larval sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) to fingerling size in tanks involved an initial feeding of rotifers for several days before the larvae were weaned to nauplii of brine shrimp Artemia spp. and prepared feed. Maintaining rotifer cultures requires space, time, equipment, supplies, and trained culturists. The rotifer cultures are often unstable, which increases risk of poor sunshine bass fingerling production in tanks. Elimination of the use of rotifers would greatly enhance the feasibility of reliable tank culture of fingerlings and should reduce production cost. This experiment compared three treatments with three replicates per treatment. In one treatment, larvae were initially fed rotifers Brachionus plicatilis and then were weaned to brine shrimp nauplii (0.48 × 0.19 mm). In a second treatment, larvae were fed brine shrimp nauplii throughout the experiment. In a third treatment, larvae were fed...

Volume and Lipid, Fatty Acid, and Amino Acid Composition of Golden Shiner Eggs during a Spawning Season

Abstract The Arkansas baitfish industry leads the nation in production of golden shiners Notemigonus crysoleucas. To determine nutritional requirements for golden shiner broodstock diets, we examined the volume and lipid, fatty acid, and amino acid composition of the eggs produced by a group of captive broodstock over a spawning season. Egg volume was 0.67 ± 0.117 mm3 (mean ± SD); egg volume declined during the spawning season. Total lipid was 15.67 ± 2.99 μg/egg, and triacylglyceride (TAG) concentration was 6.82 ± 1.81 μg/egg. Based on the stability of egg total lipid, the percent neutral lipid, the consistent contribution of TAG to neutral lipid, the consistent TAG concentration, and the stable fatty acid and amino acid profiles, we conclude that the lipid and amino acids in eggs from the experimental group were stable. The eggs should be equally sufficient for embryological development throughout the spawning season, but specific indices of egg and fry quality must be measured to confirm the links amon...

Relative Triacylglycerol and Morphometric Measures of Condition in Sunshine Bass Fry

Abstract Condition measures are assessed for wild populations of fish fry to examine production and the implications for recruitment variability. These condition measures might guide management decisions, such as those in fish culture. We developed two condition measures, one based on morphometric measurements and one based on lipid class composition, for sunshine bass (white bass Morone chrysops × striped bass M. saxatilis) fry. Prey concentrations were varied during three tank studies. Fry were sampled periodically and analyzed morphometrically and biochemically. Discriminant function analyses of morphometrics and lipid class composition were used to classify fry into treatment groups. The most successful discriminant function, which was based on morphometrics, correctly classified 75% of the test fry. We developed a condition measure based on relative triacylglycerol (TAG) content. Well-fed fry (15–20 prey/mL) had significantly higher average relative TAG values than poorly fed fry during the third wee...

Aggressive Biting among Channel Catfish in Pool Studies

Abstract Observations of marks on channel catfish Ictalurus punctatus held for varying lengths of time in experimental ponds and on fish submitted for disease analysis suggested that aggressive biting among channel catfish may sometimes occur at relatively high rates in culture ponds. Studies in experimental pools indicated that larger fish sustained an average of 4 bites per fish while smaller fish sustained less than 1 bite per fish. Unfed catfish sustained an average of 12 bites per fish while fed fish sustained 7 bites per fish. No differences in the level of aggression were observed between genders. Mortality rates, apparently due to biting, ranged from 0% to 40% during the 2–4 week periods. Biting and subsequent infection of the wounds may contribute to the unexplained losses observed by producers.

Effect of Winter Feeding Rate, Feed Form and Trigger Temperature on Yield and Condition of Golden Shiners, Notemigonus crysoleucas

Abstract Two trials evaluated winter feeding strategies for small golden shiners, Notemigonus crysoleucas destined for the crappie, Po-moxis spp. market. Fish were stocked at 615 g/pool (approximately 127 or 158 fish/m2, trials 1 and 2, respectively) in aerated, 5.9-m2 pools for 100 and 104 days, respectively. In the first trial, fish were fed a commercially available 32% crude protein crumbled, extruded pellet once daily at feeding rates of 0% (fertilizer only), 1%, or 2% of body weight/day (bw/d) on days when the afternoon air temperature was >7°C. Unfed fish lost weight, and their condition declined. Fish fed at 1% maintained both weight and condition, while fish fed at 2% gained weight. Fish in the second trial were fed once daily at 1% bw/d on those days when the air temperature was either >7°C or >10°C, with either a commercially available crumbled, extruded pellet or a sinking pellet (compressed). Fish fed crumbles were in significantly better condition at harvest than fish fed a sinking pellet, regardless of trigger feeding temperature, although average weight was not significantly different. Feeding on days with air temperatures >7°C provided 13% more feeding days than a trigger temperature >10 °C, and fish grew more over the winter. Two condition indices, relative weight (Wr) and Fultons condition factor (K), proved useful in evaluating the condition of golden shiners cultured using different feeding strategies.

Stocking Contribution and Growth of Largemouth Bass Stocked at 50 and 100 mm into Backwaters of the Arkansas River

Abstract Largemouth bass Micropterus salmoides were stocked at 50 or 100 mm total length (TL) into backwater areas of Pool 4 of the Arkansas River to determine their respective contributions to the year-class. Fifty-millimeter fingerlings were stocked at 309 fish/ha in June 2003, and 100-mm fingerlings were stocked at 62 fish/ha in August 2003. In November 2003, the percentage contributions of these fish to the year-class were 13.2% and 13.8% for the 50- and 100-mm fingerlings, respectively. Contributions in May 2004 were 17.6% and 17.2% for the 50- and 100-mm fingerlings, respectively. Stocking size and sampling year did not explain significant amounts of the variability in the contribution of stocked largemouth bass to the year-class. Poststocking catch per unit effort of wild largemouth bass did not differ among stocked and reference coves. Some stocked fish moved among backwater areas. The average lengths and weights of fish increased between November 2003 and May 2004. However, the lengths and weight...