Spawning and Larval Rearing in Hybrid Striped Bass (Morone chrysops ♀ X Morone saxatilis ♂) in Turkey

Resource sharing among stocked striped bass (Morone saxatilis), young-of-the-year white bass (Morone chrysops), and yellow bass (Morone mississippiensis) in Watts Bar Reservoir, Tennessee, was evaluated by determining distribution patterns and prey utilization. Fish were collected in 1978 by electrofishing shoreline transects near seven sites where fingerling striped bass were stocked. Electrofishing catch rates generally were positively correlated among species but preferences for substrates were not consistently detected across sample periods. Although distribution patterns were similar, the three species appeared to utilize different sizes of prey. Striped bass consumed relatively big prey such as fish larvae and large invertebrates while yellow bass mainly ate zooplankton. White bass were opportunistic, eating fish and dipteran larvae when they were abundant but consuming smaller prey at other times. Ecological segregation of the basses by food size may affect the success of striped bass introductions, but qualitative similarities of foods eaten by young-of-the-year striped bass and many other reservoir fishes indicate the need for further studies of resource use and species interactions.

The need for larval striped bass (Morone saxatilis) and hybrids of striped bass × white bass (Morone chrysops) to obtain access to air at the water surface to inflate their gas bladders was demonstrated in an experimental system. A gradual increase in salinity from 0‰ to 6.5 or 10‰ during the larval period did not increase the incidence of bladder inflation in striped bass.

The adhesiveness of eggs of white bass (Morone chrysops) can be eliminated with a tannic acid treatment, facilitating jar incubation. Fertilized eggs are added to a tannic acid solution of 150 mg/L in a McDonald jar, and the mixture is aerated with compressed air for 10–12 min. The air stone is removed, the center tube of the jar is inserted, and the water flow is adjusted to keep the eggs in motion. This treatment has been used in the production of reciprocal hybrids with striped bass (Morone saxatilis).

Sunshine bass, a hybrid of female white bass (Morone chrysops) × male striped bass (Morone saxatilis), were raised in tanks to mean weights of 1,333 g on two experimental feeds and 894 g on a commercial feed, 19 months after hatching. During 6–19 months posthatch, average weight gain and feed conversion (weight of feed fed/fish weight gained) were 2.8–3.0 g/d and 1.05–3.16 with experimental feeds versus 1.6–2.0 g/d and 1.34–4.87 with the commercial feed. After 19 months, growth on the experimental feed decreased sharply, and at 30 months mean weight was 1,710 g.

In Kansas, media attention to ice-fishing has generated a perception among nonice-fishing anglers of excessive harvests that might result in declines in population quality among white bass (Morone chrysops) populations in reservoirs. To address these concerns, creel surveys were conducted throughout ice cover at Cheney and Glen Elder reservoirs in 1985, and standard fall gill net samples collected before and after the ice-fishing season were used to measure the effect of ice-fishing on these white bass populations. The 1985 ice-fishing season was exceptional in terms of white bass catch rates and size structure. Ice anglers were selective, harvesting the largest individuals; 58% of creeled white bass were ?380 mm. White bass catchper-unit effort in standard fall gill net samples were significantly greater in 1985, but statistical power was too low to assess differences between many of the length categories. The standard sampling effort of nine net-complement-night sets for Kansas reservoirs larger than 9,000 surface acres is likely inadequate to determine population changes in highly mobile species such as white bass. Recommendations are included to better assess the effects of ice-fishing on white bass populations in Kansas reservoirs.

Biotelemetry was used to track daily and monthly distributions of white bass (Morone chrysops) in Lake Poinsett, a South Dakota glacial lake. Ultrasonic transmitters were implanted into 30 adult white bass (332–450 mm, total length) during May 1997. White bass distribution was monitored from June to October 1997, January and February 1998, and April and May 1998. Distributions were quantified using depth and distance from shore at fish location. Fish distance from shore was significantly different among dates and diel periods (P<0.05), and the interaction term was also significant. White bass in Lake Poinsett were offshore during the summer and winter. During the spring and fall, white bass were near shore in shallow waters, which may be related to spawning and feeding activities. White bass tended to be nearer the shore during the evening crepuscular period across seasons. Significant (P≤0.05) but weak (r≤0.50) correlations were found between white bass distance from shore and environmental parameters. Temperature, cloud cover, precipitation, and moon phase were significant contributors to multiple regression models, but no model explained more than 26% of the white bass distribution.

Freshwater fish grown in earthen ponds in the southeastern US can acquire “earthy” and “musty” taints due to the bioaccumulation of the cyanobacteria metabolites geosmin and 2-methyisoborneol (MIB) in the fish flesh and result in unmarketable fish. Dense cyanobacteria communities occur because nutrient inputs (phosphorus) are high in fish production ponds due to high feed application rates. In this study, hybrid striped bass (Morone chrysops x M. saxatilis) grown in earthen ponds was offered one of the six diets including diets supplemented with phytase to reduce phosphorus input to the pond and the subsequent intention of reducing the abundance of undesirable cyanobacteria. Water samples collected biweekly from each pond were analyzed for phytoplankton community structure and concentrations of geosmin and MIB. Differences in dietary phosphorus consumption among diets did not significantly affect soluble reactive phosphorus and total phosphorus concentrations, cyanobacteria abundance, and geosmin and MIB concentrations in pond water.

A study of the food and growth rate of the young white bass (Morone chrysops) was made from specimens collected between June and October, 1950 and 1951, in Lake Texoma, Texas. The major food organisms eaten by 125 young white bass in 1950 and 168 in 1951 were crustaceans (chiefly Cladocera and Copepoda), insects (chiefly Chironomidae), and gizzard shad. White bass ranging from 23 to 125 millimeters, standard length, ate all three organisms during the 5-month periods. Shad made up the largest percentage of volume of food eaten. Measurements from 349 young white bass in 1950 and 380 young fish in 1951 showed the 1951 fish grew much faster than those in 1950. The average standard length at the end of October 1950 was 74 millimeters, whereas on the same date in 1951, it was 126 millimeters. The accelerated growth of the 1951 white bass was due to the prolonged high-water level in the spring of that year and their continued heavy diet of fish.

Lake Erie Age-0 white bass (Morone chrysops) otoliths expressed daily growth increments; however, the formation of accessory primordia limited aging to the first 90 days.

Production of advanced juvenile fingerlings for stocking and for food fish production experiments in some areas of the country has been severely impacted by avian predators, especially the double-crested cormorant Phalacrorax auritius. A study was conducted to evaluate the potential of Aquashade®, a water coloring agent, to reduce predation by birds. Sunshine bass (Morone chrysops ♀ × M. saxatilis ♂) were stocked into four brackish water (8 ppt salinity) ponds. Aquashade® was applied to two ponds at a concentration of 2 mg/L, and the other two ponds were not treated. After two weeks, fish survival was higher in treated ponds compared to that in untreated ponds (96% vs. 35%). However, six weeks after stocking, average survival in the treated and untreated ponds was similar: 2% and 5%, respectively. During a subsequent non-replicated test in which Aquashade® was applied at a rate of 4 mg/L, to a pond stocked with backcrossed sunshine bass (Fi hybrid ♀ × Morone saxatilis ♂), fish survival after two weeks was 4%. During both Aquashade® tests, numerous double-crested cormorants (up to 50 individuals/0.1-ha pond) were observed feeding in test ponds. Based on the results of these tests Aquashade®, did not reduce doublecrested cormorant predation of juvenile sunshine bass or backcrossed sunshine bass hybrids raised in coastal ponds.

The white bass (Morone chrysops) is an important sport fish species in the upper Midwest. As such, understanding white bass dynamics is critical for managing its populations. Thus, we evaluated population dynamics of white bass in a northwestern South Dakota reservoir and attempted to determine whether bass recruitment patterns were more related to reservoir inflows or spring weather patterns. We found that white bass growth increased from 243 mm for age-2 fish, to 322 mm for age-6 fish, and then to 346 mm at age 9. The total annual mortality rate was 29.7%. In terms of year-class strength, white bass recruitment was erratic. The recruitment pattern was more related to spring weather patterns than reservoir inflow. In comparison, white bass population dynamics in this South Dakota irrigation reservoir were more similar to those of white bass populations in Midwestern glacial lakes than those found in southern US reservoirs.

A total of 661 white bass (Morone chrysops) was sampled for stomach content analyses from Fall River Reservoir in 1996 and 1997. White bass ate age-0 gizzard shad (Dorosoma cepedianum) almost exclusively when they were available from July to January; the mean monthly frequency of occurrence was 35%. White bass of all size categories had approximately the same frequency of occurrence of gizzard shad in their stomachs (P=0.49). There was weak correlation of white bass total length to consumed gizzard shad total length (r=0.09, P<0.0001). However, there was a positive correlation between white bass total length and number of gizzard shad consumed (r=0.53, P<0.0001). When age-0 gizzard shad were unavdable from March through June, mayflies (Ephemeroptera) and midges (Chironomidae) occurred in 28- and 21%, respectively, of mean monthly white bass stomachs.

The abundance of white bass (Morone chrysops) in Lake Erie has declined in recent years, sparking interest in mechanisms influencing its recruitment. We evaluate two mechanisms affecting recruitment: diet and the potential for competition, and storage of lipid energy reserves and the relationship to overwinter survival. The fish in our study were characteristic of white bass in the northern portion of their range, feeding predominantly on zooplankton. Only the largest age-0 white bass ate fish as a significant portion of their diet. Over the summer sampling period, we found decreasing ration sizes, expressed as a percentage of maximum ration, as the summer progressed with a concomitant decrease in the relative amount of lipid storage. In laboratory experiments, age-0 white bass held at 5°C and given food ad libitum did feed, but at rates that were insufficient to maintain body weight. Loss in weight was accompanied with a loss in lipids at a rate of 2.8 mg of lipids per gram of body weight per day. Based on our data, we concluded that age-0 white bass in Lake Erie were food-limited. Food limitation resulted in reduced growth rates, presumably related to competition with other planktivorous fishes. Reduced growth results in increased mortality and, ultimately, low recruitment through increased risk of predation by larger piscivorous fishes, reduced ability for white bass to switch to more energetically profitable piscivory and the increased likelihood of higher overwinter mortality because of reduced lipid stores.

We used the technique of Randomly Amplified Polymorphic DNA (RAPD) to produce DNA fingerprints of white perch (Morone americana) and yellow bass (Morone mississippiensis), which recently have invaded and are sympatric in Browning Oxbow, Kansas/Missouri. Total DNA isolated from liver of 20 specimens of each species resulted in similar RAPD amplification patterns with the exception of a 300 base pair DNA band unique to white perch. The incidence of natural hybridization between Morone species leads to concern about possible genetic introgression with native white bass (Morone chrysops).

We assessed the relative precision among scales, sagittal otoliths, and opercles for determining age and estimating the growth of 124 white bass (Morone chrysops). Percent agreement for age among the three structures was 72.1%. Scale assessments provided the highest percent agreement between readers within structures (89.6%). Opercles provided the highest agreement with final estimated fish ages (94.8%). Average percent error values were < 3.0 for all comparsions. It was difficult to detect white bass annuli on scales when estimated ages exceeded six years. Fish ages estimated from otoliths and opercles ranged from 1 to 12 years. Ages determined from scales differed as much as four years from otoliths and opercles for fish older than age 6. Total length to structure radius relations were strongly correlated for scales and opercles. No significant differences were detected between mean back-calculated lengths determined from scales and opercles. Although scales, otoliths, and opercles provided similar precision in determining age and growth of white bass up to age 6, the precision of scales as estimators decreased with fish age after age 6.