Male White Bass Research Articles

Comparison of Growth Between Morone Hybrids (Palmetto and Sunshine) in Earthen Ponds

AbstractPalmetto bass are produced by crossing the female striped bass, Morone saxatilis, with the male white bass, Morone chrysops; whereas, the sunshine bass is the reciprocal cross. The hybrid striped bass industry typically rears sunshine bass in earthen ponds, because of the ease of handling, availability, and early maturation of the white bass female broodstock. Growth performance has been assumed similar between the crosses. Under commercial pond conditions, sunshine bass (19.8 ± 0.4 g (mean ± SEM)) and palmetto bass (23.2 ± 0.3 g) were grown to market size (617.0 ± 17.2 g sunshine and 620 ± 3.6 g palmetto) within 15 mo, yielding 4532.6 kg/ha. The net production between the crosses was not significantly different and averaged 4373.4 kg/ha. Feed conversion ratio (FCR) of sunshine bass (FCR 1.70) was better (P = 0.0158) than palmetto bass (FCR 1.76). Commercial processing metrics of each cross demonstrated significant differences, with sunshine bass exhibiting lower frame waste (P = 0.0457) than palmetto bass, probably due to fish body shape or conformational differences at this size. Without growth performance differences between the hybrids, there might be an advantage to rearing sunshine bass due to the slightly better FCR and increased skinless boneless fillet yield.

Evaluation of Precision and Sample Sizes Using Standardized Sampling in Kansas Reservoirs

AbstractWe evaluated the precision of samples and the number of stock‐length fish collected by means of standard methods used for sampling North American freshwater fishes from 2010 to 2013 in Kansas. Additionally, we used resampling procedures to determine the number of gear deployments needed to achieve a relative standard error (RSE) of 25% for the CPUE and collect 100 stock‐length individuals. Median RSE of electrofishing samples was generally less than 25% for Largemouth Bass Micropterus salmoides in all sizes of reservoirs and for Channel Catfish Ictalurus punctatus in medium (251–1,000 acres) and large reservoirs (greater than 1,000 acres). The RSE estimates were generally >25% for Bluegill Lepomis macrochirus and crappies Pomoxis spp. collected in trap nets and palmetto bass (female Striped Bass Morone saxatilis × male White Bass M. chrysops) and Walleye Sander vitreus sampled in gill nets. With few exceptions, 100 stock‐length individuals of all target species (e.g., Largemouth Bass, Bluegill, crappies, palmetto bass, Channel Catfish, Walleye) were not sampled at current levels of effort. Resampling procedures indicated that fewer than 20 deployments were usually needed to obtain an RSE ≤ 25% and 100 stock‐length fish for Largemouth Bass in smaller impoundments (i.e., <250 acres); however, more than 20 deployments were needed in larger impoundments. The median effort needed to achieve an RSE ≤ 25% for Bluegills and crappies in trap nets varied and may exceed what some biologists find practical. Fewer gill‐net deployments were needed to reach an RSE ≤ 25% for palmetto bass and Walleyes than to collect 100 stock‐length fish. Our results indicate that more samples than are currently prescribed are generally needed to precisely sample sport fishes by means of standardized protocols in Kansas reservoirs. In some instances, obtaining precise samples may not be logistically feasible. In these situations, biologists should be aware of the potential shortcomings of sampling protocols and set objectives accordingly.Received May 12, 2014; accepted August 23, 2014

Responses of gizzard shad and white crappie to introductions of palmetto bass

Palmetto bass (female striped bass Morone saxatilis × male white bass Morone chrysops) were stocked into Long Branch Lake, Missouri, USA in an effort to restructure the gizzard shad Dorosoma cepedianum population via predation. The goal of this restructuring was to provide more suitable-size prey for white crappie Pomoxis annularis, thereby improving growth of this important sport fish. Secondarily, palmetto bass may prey on the abundant white crappie population which may reduce density-dependent effects on growth. Trends in abundance and mean total length (TL) at age of white crappie and gizzard shad were examined over an eight-year period which spanned years before, during, and after stocking of palmetto bass. Also, trends in water quality and zooplankton variables, which may influence gizzard shad demographics, were examined during this period. Following stockings of palmetto bass, mean TL at age of adults and abundance of age-0 gizzard shad increased. Water quality variables and zooplankton biomass that may have influenced gizzard shad showed no temporal trends except for turbidity which increased over time. Despite the changes in the gizzard shad population, mean TL at age of white crappie did not improve and their abundance did not decline. Age-0 gizzard shad still quickly outgrew their vulnerability to most white crappie. It may be necessary to incorporate other management strategies in addition to stocking palmetto bass to improve growth of white crappie in this reservoir.

Investigating the Utility of Measuring 11α‐Ketotestosterone and Vitellogenin in Surface Mucus as an Alternative to Plasma Samples in Assessments of the Reproductive Axis of White Bass

AbstractSex steroids and vitellogenin measured in plasma have been used in a variety of fish species to investigate the reproductive system. Surface mucus has been shown to be an effective substitute for plasma in several species of fish. The goal of this study was to investigate the utility of mucus sampling as an approach to investigating the hypothalamic–pituitary–gonadal (HPG) axis in White Bass Morone chrysops. We measured 11α‐ketotestosterone and vitellogenin in both surface mucus and plasma samples from White Bass collected from a wild population during their annual spawning migration. Mucus and plasma samples were collected from male and female White Bass that were treated to stimulate the HPG axis (carp pituitary extract, 10 mg/kg; estradiol, 10 mg/kg) or treated with saline injections. Mucus and plasma concentrations of both vitellogenin and 11α‐ketotestosterone were positively correlated with one another. Treatments with estradiol led to higher amounts of vitellogenin in both plasma and mucus in both male and female fish. Assessments of 11α‐ketotestosterone in mucus correctly identified the sex of 90% of spawning White Bass, as did vitellogenin in 94%. These data demonstrate the potential utility of mucus sampling as a tool to less invasively assess the annual reproductive cycle, identify stimulation of the HPG axis, and identify fish sex in hatchery populations of White Bass.

A Proposed Change to Palmetto Bass Proportional Size Distribution Length Categories

AbstractPalmetto bass (female striped bass Morone saxatilis × male white bass M. chrysops) are an important sport fish in the Southeast and Midwest regions of the United States. Because palmetto bass populations must be established and maintained by regular stocking, population assessments are necessary to evaluate and refine stocking plans. A commonly used metric for fish population assessment is the proportional size distribution (PSD). However, the value of this metric is limited for palmetto bass because the original lengths designated for the stock (8 in), quality (12 in), preferred (15 in), memorable (20 in), and trophy length categories (25 in) were based on the old world‐record length of 31 in, which is much shorter than the current length of 39 in. Thus, new lengths of 10, 16, 20, 24, and 28 in are proposed for assessing palmetto bass populations via PSD indices. These proposed lengths more accurately reflect the maximal length and life history characteristics (i.e., fast growing, short lived, and seldom stunting) of palmetto bass than the current PSD length categories. With the proposed length categories, PSD estimates are likely to provide a more useful index of the growth, mortality, and recruitment of palmetto bass and improve communication among fisheries managers.Received February 21, 2011; accepted May 8, 2011

Efficacy of Oxytetracycline Marking of Fingerling Palmetto Bass in Hard Water

AbstractAn oxytetracycline hydrochloride (OTC) marking study was used to determine an OTC concentration that would successfully mark palmetto bass (male white bass Morone chrysops × female striped bass M. saxatilis) in hard hatchery water (hardness as CaCO3 = 500 mg/L). Outcomes for juvenile palmetto bass immersed for 6 h in 500‐ and 700‐mg/L concentrations of OTC mixed with hard water were compared to determine whether 14‐d marking mortality and mark intensity at 14 and 344 d postimmersion differed between immersion concentrations. Sagittal otoliths were examined for marks at 14 d; lapillus otoliths were examined for marks at 344 d. Marking mortality was not detectable after 14 d, but identification and intensity of sagittal otolith marks at 14 d postimmersion were poor for both OTC concentrations. Oxytetracycline marks were identified in 63% (500 mg/L) and 74% (700 mg/L) of the sagittae examined at 14‐d postimmersion, whereas marks were found in 87% (500 mg/L) and 95% (700 mg/L) of lapilli examined at 344 d postimmersion. The 700‐mg/L OTC concentration yielded better mark intensity results than the 500‐mg/L concentration in lapilli at 344 d postimmersion.

Accuracy of Angler‐Reported Harvest in Roving Creel Surveys

AbstractHarvest data obtained during roving creel surveys are often based on angler‐reported information without validation. Angler creels were inspected following interviews during roving creel surveys on three Florida lakes. Comparisons between reported and counted harvest revealed significant differences for anglers targeting sunfish Lepomis spp. (22% error) and black crappie Pomoxis nigromaculatus (7% error). Differences were negligible for anglers targeting sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis), palmetto bass (male white bass × female striped bass), and largemouth bass Micropterus salmoides. Accuracy among species was inversely related to bag limit size; this was attributed to a combination of factors, including species, number and size of fish harvested, limit‐conscious behavior of anglers, and differences among angler groups. Accuracy within species was not significantly influenced by the reported number of fish harvested or trip duration, nor was the interaction of the two significant. Daily total harvest estimates based on reported data were biased for sunfish (19% error) and black crappies (5% error), but correction factors were effective in reducing total errors to 2% for both species. Inspection of creels is recommended for all roving creel survey interviews when accuracy is critical to meeting study objectives. When moderate accuracy is sufficient, angler‐reported harvest may be used if validated or adjusted with a correction factor if found to be inaccurate.

Size‐Specific Angling Return Rates of White Bass in Kansas Reservoirs

AbstractThe size selectivity of angling for white bass Morone chrysops in Kansas reservoirs was evaluated through a 3‐year tagging study on five reservoirs. Nearly 6,500 white bass were tagged with Floy FD‐94 anchor tags, and tag return postcards were used to quantify size‐specific angling return rates. The range for length of fish tagged was 200–573 mm, and the range for length of fish recaptured was 225–492 mm. Size selectivity was similar for male and female white bass between 230 and 460 mm. Larger white bass, particularly males, may be more vulnerable to angling exploitation, but small sample sizes of these fish (0.5% of fish tagged in this study were greater than 450 mm) hinder confirmation of this supposition. Return rates suggest that length limits lower than 300 mm may be ineffective for restructuring white bass populations and would provide little benefit to anglers.

Use of Resampling to Evaluate a Simple Random Sampling Design for General Monitoring of Fishes in Texas Reservoirs

AbstractTraditional formulae used to estimate sample sizes to achieve a desired level of precision have been proven to underestimate required sample sizes. Further, because these formulae typically focus on precision, they are unable to provide the information needed to evaluate the risk of not attaining other sampling objectives. Resampling approaches provide a framework for estimating realistic sample sizes, can handle complex objectives, and will provide probability‐based statements that can be used to assess risk. We used a resampling approach to assess the performance of a simple random sampling design for the general monitoring of fishes with electrofishing, gill nets, and trap nets in Texas reservoirs. We evaluated median relative standard error (RSE = 100 × SE of the estimate/estimate) of catch‐per‐unit‐effort (CPUE) estimates of stock length fish with current sampling methods. We estimated the effort necessary to achieve RSEs of (at worst) 25% or 15% (RSE25 and RSE15, respectively) at various probability levels. Resampling estimates of effort needed to achieve RSE25 were compared with estimates calculated from one commonly used formula (N = (CV/RSE)2) for all target species. Further, we estimated the effort necessary to collect 100 stock length fish of each target species. Median RSE ranged from 22 for largemouth bass Micropterus salmoides to 43 for crappies Pomoxis spp. The median number of stock length fish collected using the current sampling effort ranged from 16 for blue catfish Ictalurus furcatus to 43 for palmetto bass (male white bass Morone chrysops × female striped bass M. saxatilis) per sampling event. Estimated sampling effort needed to achieve RSE25 for largemouth bass and to collect 100 stock length largemouth bass at the 75th percentile of samples was 29 and 62 5‐min stations, respectively. Estimated sampling effort needed to achieve RSE25 at the 75th percentile of samples for other target species ranged from 32 net‐nights for channel catfish I. punctatus to 59 net‐nights for crappies. Estimated sampling effort needed to collect 100 stock length fish from gill nets and trap nets at the 75th percentile of samples ranged from 72 net‐nights for crappies to over 100 net‐nights for blue catfish. Simple random sampling generally resulted in low catches of stock length fish and a poor precision of CPUE estimates, especially for target species collected with gill nets and trap nets. Sampling effort estimates (from N = (CV/RSE)2) underestimated the sampling effort needed for all species examined. Unlike traditional sample size formulae, the resampling approach presented here allows the user to determine sampling effort with an associated probability of success in achieving a particular level of precision or in collecting a given number of fish.

Growth Performance and Body Composition of Palmetto Bass Fed Five Levels of Dietary Protein at Two Energy‐to‐Protein Ratios

AbstractA feeding trial was conducted to determine the effects of dietary crude protein (CP) level and digestible energy‐to‐protein (DE:P) ratio on the growth performance and body composition of palmetto bass (female striped bass Morone saxatilis × male white bass M. chrysops). Ten soybean‐meal‐based diets were prepared to contain 30, 35, 40, 45, or 50% CP at DE:P ratios of 33.48 or 41.85 kJ/g CP. The diets contained lyophilized palmetto bass muscle as the sole animal protein source to improve dietary amino acid composition. Wheat middlings and corn grain were the major sources of carbohydrates, and the diets were formulated to meet the known nutritional requirements of palmetto bass. Fish fed 35% or 40% CP at 33.48 or 41.85 kJ/g CP had significantly (P ≤ 0.05) greater weight gains and higher feed efficiency ratios than fish fed the other diets. The protein efficiency ratio (g weight gain/g CP consumed) decreased and visceral fat ([g visceral fat × 100]/g body weight) increased as the dietary protein level increased in both DE:P treatments. The hepatosomatic index ([g liver weight × 100]/g body weight) increased with the dietary protein level up to 40–45% CP. Whole‐body muscle content and fillet yield did not differ significantly among fish fed any of the diets at either DE:P ratio. The lipid content of fillets was higher among fish fed 45–50% CP than among those fed up to 40% CP. Hematocrit and serum protein concentrations were not affected by the dietary CP level or the DE:P treatment. Overall, the DE:P ratio had little or no effect on most of the parameters of interest. Based on our comparisons of weight gain, diet utilization efficiency, and body composition among treatment groups, a 35% CP diet with 41.85 kJ/g CP was considered optimum for palmetto bass under the conditions of this study.

A Comparison of Gill Netting and Electrofishing as Sampling Techniques for White Bass in Missouri's Large Reservoirs

I compared fall gill netting with spring electrofishing to determine which method best represented the population abundance and size structure of white bass Morone chrysops in two Missouri reservoirs. Gill nets caught all ages and sizes of white bass, and both sexes were equally represented. Median catch rates were variable but were usually less than 10 fish/gill-net day. Mean annual electrofishing catch rates peaked after mid-April and ranged from about 50–180 fish/h. Electrofishing did not reflect the size structure because it caught primarily male white bass (about 90% of the sample), which are smaller than females of the same age, and the catch rates of immature (age-1) fish were low (usually < 10 fish/h). The catch rates of the two methods were not related to each other, but both appeared to reflect large changes in population abundance. The age frequencies of the sexes and the relative differences in year-class strength were similar with both methods. I recommend fall gill netting for sampling white bass in Missouri reservoirs because all ages and both sexes were represented in the samples, which resulted in earlier assessments of recruitment and better assessments of size structure.

Impacts of Increased Tempering Lengths on Twenty-Four-Hour Survival of Hybrid Striped Bass Fry

Abstract We evaluated the impacts of different tempering rates on the 24-h survival of 4-d-old palmetto bass (female striped bass Morone saxatilis × male white bass M. chrysops). We used the increase rate of pH as a measure of water quality change. Four tempering rates were conducted concurrently to determine the importance of extended tempering time on the survival of fry following an adjustment to an increase in pH, alkalinity, and hardness. Fry were tempered to increases of 0.6–1.9 pH units over periods from 11 to 330 min, producing pH tempering rates of 11.4–0.02/h. The study produced average tempering rates and average survival rates for a set of controls and four treatment groups. Average fry survival rates ranged from 75% in the control replicates with a pH tempering rate of +0.01/h to 48% for fry subjected to an increase of 1.9 pH units in 10 min or a tempering rate of +11.4 pH/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...

Aquaculture Performance Comparison of Sunshine Bass, Palmetto Bass, and White Bass

Abstract Aquaculture performance of phase II and phase III sunshine bass (a female white bass Morone chrysops × male striped bass M. saxatilis), palmetto bass (a female striped bass × male white bass), and white bass were evaluated in separate 12-week yield trials conducted in indoor recirculating-water systems. Phase II sunshine bass, palmetto bass, and white bass had mean initial weights of 40.0 g, 39.7 g, and 41.0 g, respectively. A diet containing 40.2% crude protein (CP) was fed to fish twice daily at a rate of 3% body weight/d. At the end of the trial, sunshine bass and white bass had mean weights of 124.2 g and 126.0 g, respectively and were significantly larger than palmetto bass (93.5 g mean weight). Phase II sunshine bass and white bass outperformed palmetto bass by having higher relative growth (h), mean daily growth, and relative weight, as well as better feed conversion ratios (weight of food fed/weight gained). Survival was 100% for all three taxonomic groups. In the phase III study, mean in...

Correlation of Transforming Growth Factor-β Messenger RNA (TGF-β mRNA) Expression with Cellular Immunoassays in Triamcinolone-Treated Captive Hybrid Striped Bass.

Assessing fish immune status with molecular markers has been hampered by a lack of specific reagents. A quantitative polymerase chain reaction (PCR) method (reverse transcription quantitative-competitive PCR, RT-qcPCR) for measuring transforming growth factor-β (TGF-β) transcription from a broad range of teleost fish has recently been developed. The quantitative PCR now permits monitoring production of this important immunosuppressive cytokine in response to immunomodulating agents and conditions. We examined anterior kidney and spleen mononuclear cells from hybrid striped bass (female striped bass Morone saxatilis × male white bass M. chrysops) for production of TGF-β messenger RNA (mRNA) in response to administration of the synthetic glucocorticoid triamcinolone. We also compared TGF-β transcription with anterior kidney macrophage bactericidal activity and splenic lymphocyte blastogenesis. Anterior kidney mononuclear cell TGF-β mRNA levels decreased, whereas bactericidal activity increased. Spleen TGF-β mRNA levels did not change significantly, and splenic lymphocyte pokeweed mitogen stimulation index increased in triamcinolone-treated fish. Since triamcinolone is used therapeutically as a suppressive immunomodulator, the enhanced immune functions indicated by the cellular immunoassays were unexpected; however, the inverse response of TGF-β production and macrophage bactericidal activity was consistent with the known relationship between TGF-β and macrophage activation in mammals. Induced immunomodulation in hybrid striped bass was detectable by both traditional cellular immunoassays and the new RT-qcPCR for TGF-β.

Cold Tolerance and Fatty Acid Composition of Striped Bass, White Bass, and Their Hybrids

Abstract Cold tolerance of striped bass Morone saxatilis, white bass M. chrysops, palmetto bass (female striped bass × male white bass), and sunshine bass (female white bass × male striped bass) were compared under controlled laboratory conditions. Two groups of each taxon were acclimated at 20°C in a recirculating-water system housed in an environmental chamber and were fed either a natural or prepared diet for 84 d. The fatty acid composition of the natural diet was 13% more unsaturated than that of the prepared diet. Fish fed the natural diet subsequently had unsaturated: Saturated fatty acid ratios 10-25% higher than fish fed the prepared diet. After being subjected to identical simulated cold fronts (10°C drop in surface water temperature, as if the fish were confined in cages or pens), all groups of fish fed the prepared diet suffered high mortality (50-90%) whereas there was zero mortality among the groups receiving the natural diet. White bass and sunshine bass fed the prepared diet had higher sur...

Evaluation of Two Sizes of Hybrid Striped Bass for Introduction into Small Ponds

Abstract Private recreational fisheries in small impoundments provide a potential new market for the growing industry producing hybrid striped bass Morone saxatilis. We estimated growth, condition, and survival of hybrid striped bass (female striped bass × male white bass M. chrysops) in two small ponds with established fisheries for largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus that eventually experienced severe weather-induced fish kills 266 d and 348 d after stocking. Both ponds were stocked with 40 phase 2 (120–169 mm total length, TL) and 22 phase 3 (241–344 mm TL) hybrid striped bass/ha. Growth and condition were monitored from introduction until the occurrence of fish kills. Fish collections immediately following the kills allowed minimum estimates of survival for time at large before each event. Mean growth rates were near 0.35 mm/d for phase 2 hybrids and ranged from 0.13 to 0.21 mm/d for phase 3 hybrids. Mean relative weight (Wr ), which at the time of stocking was optim...

Comparative Production Characteristics of Sunshine Bass and Sunshine Bass × Striped Bass in Recirculating-Water Systems

The production characteristics of juvenile sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis)and juvenile backcrosses (female sunshine bass × male striped bass) were compared in a 56-d growth trial in recirculating-water systems. Survival, growth, and feed conversion ratios were similar (P < 0.05). Condition factors of the sunshine bass were significantly higher. The results of this study indicate that juvenile sunshine bass and the sunshine bass × striped bass backcross perform similarly in culture situations and that the backcross may offer an alternative to sunshine bass and palmetto bass (male white bass × female striped bass) in the hybrid striped bass industry.

Palmetto Bass Movements and Habitat Use in a Fluctuating Colorado Irrigation Reservoir

Abstract Movement and habitat use by adult palmetto bass (female striped bass Morone saxatilis × male white bass M. chrysops) were monitored with ultrasonic transmitters in a 1,166-ha fluctuating irrigation reservoir in eastern Colorado. Movement varied by diel periods, and heterogeneity was recorded among individuals. Minimum estimates for displacement ranged from 30 to 558 m/h. Factors that appeared to influence movement included water clarity, water temperature, and barometric pressure, although these relationships explained little variability in the multiple-regression model used. Palmetto bass exhibited a preference for nearshore areas, but they did not select for cover types within that region. As the water level in the reservoir was reduced through irrigation drawdown, the fish used deeper areas of the lake than during periods of water level stability. Knowledge of the influence of these variables on activity patterns should help improve catch rates for anglers and sampling efficiency for biologists.

Effects of Dietary Catfish and Menhaden Oils on Hybrid Striped Bass Production

Abstract Hybrids of female striped bass Morone saxatilis and male white bass M. chrysops were stocked at 14,000 fish/ha in earthen ponds and fed an experimental diet supplementally sprayed (2.5% by weight) with either catfish oil (CO) or menhaden oil (MO). The sprayed diet contained n-3 highly unsaturated fatty acids (HUFA, with four or more double bonds) at 1.10% and 1.54% of diet for CO and MO, respectively. Fish were fed to apparent satiation twice daily for 212 d in three replicate 0.05-ha ponds per diet. There were no significant differences (P < 0.05) between CO and MO diets in mean total weight offish at harvest (590 and 585 g, respectively), percent weight gain (584% and 576%), survival (87% and 91%), or feed conversion (weight of feed as fed/fish weight gain: 2.50 and 2.31). Mean intraperitoneal fat (IPF) to body weight ratios of fish were not different (4.8% for CO and 4.4% for MO). Females had a significantly higher IPF ratio (5.2%) than males (4.7%) across both diets. There were no significant...