Survival of juvenile striped bass (Morone saxatilis) and Morone hybrid bass (Morone chrysops × Morone saxatilis) increased by addition of calcium to soft water

CaCl₂ was used to increase the total hardness of water in three ponds from 20 to 45–100 mg/l as CaCO₃ 5 days before harvest. CaCl₂ was also used to increase hardness from 10 to 70–200 mg/l as CaCO₃ in water used for holding and transporting fish after they were harvested from ponds. All groups of fish in water containing additional calcium had 80–99% survival compared with 16% survival for a group of fish without additional calcium in the water before or after harvest. Addition of 1% NaCl to the water did not increase survival.     

杂交条纹鲈苗种培育试验

杂交条纹鲈即条纹鲈♂与白鲈♀的杂交种 ,它不仅适合于增殖、游钓 ,也有很大的养殖潜力。我省于 2 0 0 1年 5月从美国引进杂交条纹鲈仔鱼 ,经 86天的精心培育 ,结果鱼平均体重达 2 5ｇ ,体全长13 5ｃｍ ,成活率 30 %。1　试验材料与条件1 1　仔鱼来源及运输 :杂交条纹鲈仔鱼来源于美国田纳西州 ,鱼苗体质健壮 ,经 36小时陆、空运输 ,于5月 2 4日放养于河北省苗种繁育中心试验场 ,放养10 5万尾。1 2　池塘条件 :试验池为水泥板护坡池 ,沙质底。鱼苗下塘前排干池水曝晒一个半月 ,并施生石灰 (加水兑成浆状全池泼洒 ) ,而后加水至水深 80ｃｍ …     

美国条纹鲈养殖技术

美国条纹鲈(MoroneSaxatits)又名银花鱼,原产于美国密西西比河流域。1997年,福建省泉州市丰泽区从美国引进美国条纹鲈试养,获得成功,并于2000年突破了人工繁育技术难关,使得该鱼作为淡水新引进的优良品种在福建省乃至全国大规模的推广养殖,并取得较好的经济效益和社会效益。一、美国条纹鲈主要的生物学特性条纹鲈个体大,体色鲜艳,无肌间刺,肉质幼滑,营养丰富,富含ONEGH3和高度不饱和脂肪酸。条纹鲈生存的适温范围广(2℃~36℃),最佳生长水温20℃~29℃,广盐性,在淡水、半咸水中均可生存。其食性杂(偏肉食),喜欢摄食人工配合饲料,生长速度快…     

鲈鱼养殖技术之二条纹鲈池塘养殖技术

条纹鲈(Morone Saxatilis),又名条纹石、条纹狼鲈、线鲈、淡水石斑等,隶属于鲈形目、鲈科、狼鲈亚科,是一种溯河性鱼类.条纹鲈是美国的一种传统养殖鱼类,生长速度快,对环境适应性强,尤其对盐度及水温的适应范围广,适宜淡水及咸淡水养殖,有"淡水石斑"之称.     

美国条纹鲈的池塘养殖技术

美国条纹鲈，学名海鲈(Morone saxatilis)．又名美洲狼鲈、条鲈、线鲈、淡水石斑等，隶属于鲈形目，鳍鲈科，狼鲈亚科，是一种溯河性鱼类，为美国的传统养殖鱼类。该鱼生长速度快，对环境的适应性强，尤其是对盐度及水温的适应范围广，适合于在淡水及咸淡水水体中养殖。其肉质细嫩鲜美，营养丰富，可与我国名贵的鳜鱼相媲美。美国     

Compensatory Growth of Pond-reared Hybrid Striped Bass, Morone chrysops × Morone saxatilis, Fingerlings

Compensatory growth (CG) or “catch‐up growth” is a period of super‐accelerated growth following a period of suboptimal conditions (i.e., lack of prey availability or overwintering). Little is known about the CG response in pond‐raised fish and whether hybrid striped bass (HSB), Morone chrysops × Morone saxatilis, might exhibit the rapid growth states or improvements in other production characteristics that may accompany the response. To evaluate the potential for CG in HSB culture, a 16‐wk growth trial in twelve 0.1‐ha earthen ponds was conducted. Approximately 2850 fish (mean weight ± SD = 3.2 g ± 1.1) were stocked into ponds and subjected to one of four cyclic feeding regimens. Treatment regimens included a control (0 wk, fed twice daily to apparent satiation) and cycles of 1, 2, or 4 wk of feed deprivation, followed by 1, 2, or 4 wk of feeding to apparent satiation. Fish in the 4‐wk feeding regimen were offered feed twice during the feed‐deprivation period (once every other week). Growth, specific growth rate (SGR), hepatosomatic index (HSI), intraperitoneal fat ratio, and condition factor (CF) were measured every other week, while overall growth, feed efficiency (FE) (FE = [weight gain/feed fed] × 100), and survival were calculated at the trial termination. The effect of these feeding regimens on water quality was examined by monitoring pH, turbidity, total ammonia nitrogen, nitrite–nitrogen, nitrate–nitrogen, soluble reactive phosphorus, and chlorophyll a weekly; total nitrogen and phosphorous biweekly; and dissolved oxygen and temperature twice daily. Cyclic feeding elicited CG; fish subjected to the 2‐wk regimen had a significantly higher SGR than 0‐wk controls during all but the final refeeding period. FE was higher for all fish in the cyclic regimens, although only FE for fish in the 2‐wk regimen was statistically greater (40%) than the controls. HSI was the most responsive measure and significantly decreased in the 2‐ and 4‐wk treatments during feed‐deprivation period and overcompensated during the refeeding period. CF also varied with feeding cycle and proved to be an effective nonlethal measure of predicting a CG response. No statistical differences in water quality parameters were observed. These data suggest that CG can be effectively induced in pond‐raised HSB and that the increase in FE warrants further research for practical application. Future pond studies with fingerling HSB fish should be conducted with emphasis on feed‐deprivation periods of 2 wk and refeeding periods of at least twice that of the feed‐deprivation period.     

Therapeutic and prophylactic immunization against Streptococcus iniae infection in hybrid striped bass (Morone chrysops×Morone saxatilis)

Vaccination strategies have traditionally been used as preventative or prophylactic measures against disease (prophylactic immunization) in uninfected fish. Alternatively, therapeutic or remedial measures, such as antibiotic administration, are commonly employed to treat disease in infected fish. Vaccination as a therapeutic measure (therapeutic immunization), however, has not been adequately explored in sub‐clinically infected fish. Therapeutic and prophylactic immunization with three Streptococcus iniae vaccines, formalin‐killed whole S. iniae cells (FKC vaccine), concentrated S. iniae extracellular products (greater than 2 kDa) (ECP vaccine) and a combination of killed cells and extracellular products (FKC+ECP vaccine), were tested in hybrid striped bass, Morone chrysops×Morone saxatilis, previously naturally infected with S. iniae. Fish (mean weight 10.0 g) were injected intraperitoneally (IP) or intramuscularly (IM) with one of each of the vaccines, tryptic soy broth (TSB‐control) or non‐injected (non‐injected control) to evaluate therapeutic effects (Trial 1). Survivors of the natural infection and ECP and FKC+ECP vaccine immunization and another lot of non‐injected control fish were immersion challenged with 1.47 × 10⁶ CFU of S. iniae mL^?1 at 44 days post‐immunization to evaluate vaccine efficacy (Trial 2). Hybrid striped bass (1.0 g) were also IM injected with S. iniae ECP vaccine at an aquaculture facility and immersion challenged with 1.47 × 10⁶ CFU of S. iniae mL^?1 12 weeks post‐immunization (Trial 3). The ECP and FKC+ECP vaccines, regardless of injection route, significantly (P<0.001) increased survival in asymptomatic, sub‐clinically infected fish thereby providing therapeutic merit. Hybrid bass immunized IP or IM had mean per cent survival values ranging from 78 to 96 at 44 days post‐immunization (Trial 1) and 69–97 post challenge (Trial 2). Survival of fish injected with TSB or immunized with FKC vaccine was significantly lowered and ranged from 12 to 13 by IP injection and 40 to 50 by IM injection and thus, the FKC vaccine had no therapeutic effect. The survival of hybrid striped bass IM immunized with S. iniae ECP vaccine in field Trial 3 was 91 and the RPS was 83. These results demonstrate that therapeutic immunization using S. iniae ECP and FKC+ECP vaccines can control a natural S. iniae infection. Furthermore, S. iniae ECP or FKC+ECP vaccines can also be used prophylacticly to protect hybrid striped bass against subsequent pathogen challenge.     

The Cryopreservation of Striped Bass Morone saxatilis Semen

Abstract.— Two experiments were designed to improve upon existing methods for cryopreserving striped bass Morone saxatilis , semen. In the first experiment, two extenders, two cryoprotectant concentrations, and two freezing rates were evaluated on the basis of post-thaw semen motility after 1, 7, and 30 d of storage at −196 C. Semen samples cryopreserved at a freezing rate of −40 C/m resulted in a significantly higher percentage of motile sperm ( P < 0.001) and longer duration of spermatozoa motility ( P < 0.001) than samples cryopreserved at a freezing rate of -30 Chin. Also, the cryoprotectant dimethyl-sulfoxide yielded a significantly higher percentage of motile sperm ( P < 0.001) and longer duration of spermatozoa motility ( P < 0.001) when a 5% concentration was used instead of 7.5%. In the second experiment, the two extenders from Experiment I were re-evaluated and a new extender, which was a modified version of Extender 1, was tested. The samples were cryopreserved at -40 C/min with 5% DMSO and thawed in a 25 C water bath. Spermatozoa motility and fertilization ability were evaluated, and semen cryopreserved in Extender 2 yielded the longest duration of spermatozoa motility ( P < 0.001). the highest percentage of motile sperm ( P < 0.001). and the highest percentage of fertilized eggs ( P < 0.002) in comparison to Extenders I and 3.     

Genetic effects on carcass-quality traits in hybrid striped bass (Morone chrysops♀×Morone saxatilis♂)

A 10 × 10 factorial mating design was used to examine the genetic effects on various carcass‐quality traits in hybrid striped bass (Morone chrysops♀×Morone saxatilis♂). A total of 448 offspring were raised in a ‘common‐garden’ environment and carcass‐quality traits were assessed at 389 days post fertilization; parentage of each fish was inferred from genotypes at 5–10 nuclear‐encoded microsatellites. There was a significant effect of dam and sire on body weight and fillet weight and a significant effect of dam on viscera weight and condition factor. When carcass‐quality traits were standardized to body weight, there was a significant effect of dam, sire and dam × sire interaction on viscera percentage (proportion of viscera weight to body weight). Phenotypic correlations between body weight and non‐standardized carcass‐quality traits were high (r_p=0.80–0.92), whereas phenotypic correlations between body weight and standardized carcass‐quality traits were low (r_p=0.13–0.19). Genetic correlations between body weight and fillet weight (dams and sires), and body weight and viscera weight (dams only) were significant and positive, while the genetic correlations between body weight and viscera percentage (dams and sires) were significant and negative. Significant general combining ability values for favourable carcass‐quality traits in the same breeder (dam or sire) occurred only in one or two of 20 (dams and sires) used in this study, suggesting that simultaneous improvement in multiple traits in hybrid striped bass may require evaluation of large numbers of candidate breeders. The effect of sex on body weight and all non‐standardized carcass‐quality traits was significant and appeared to be due to faster growth in females. These results indicate that selection for faster growth of hybrid striped bass would lead to a correlated increase in fillet weight and viscera weight but not necessarily to an increase in the proportion of fillet and waste product generated. The significant dam, sire and dam × sire interaction effects on viscera percentage and the negative genetic correlations between body weight and viscera percentage indicate that selection for reduced proportion of viscera relative to body weight might be feasible.     

条纹鲈人工繁殖及苗种培育技术初探

条纹鲈又称银花鱼 ,学名ＭｏｒｏｎｅＳａｘａｔｉｌｉｓ,原产于美国密西西比河 ,是美国淡水养殖的主要品种。该鱼个体大 ,适温范围广 (2～ 36℃ ) ,最佳生长水温 2 0～ 2 9℃。广盐性 ,在淡水、半咸水中均可生存。肉食性 ,人工驯食后能完全摄食人工配合饲料。鱼体肉质好 ,营养丰富 ,富含不饱和脂肪酸 ,是极具发展潜力的水产养殖新品种。我所于2 0 0 0年 3月在泉州进行人工繁殖及苗种培育试验 ,取得重大突破。并达到批量育苗。现在此次试验情况报告如下。1　材料和方法1 1　人工繁殖1 1 1　亲鱼来源与培育此次人工繁殖所有亲鱼是 1997年从美…     

Multiple vitellogenins in white perch (Morone americana)

Three forms of female-specific plasma protein were purified from blood plasma of estrogen-treated white perch, characterized, and classified as three distinct vitellogenins (VgA, VgB, and VgC). This study describes the first purification of three classes of native Vg from any vertebrate and sets the stage for discovery of the different functions of each type of Vg.     

Quantitative dietary lysine requirement of juvenile striped bass Morone saxatilis

Two feeding trials of 8 and 10 weeks each were conducted to quantify the dietary lysine requirement of juvenile striped bass, Morone saxatilis. Diets in both experiments contained approximately 420 g crude protein kg^–1 and 13.4 MJ digestible energy (DE) kg^?1. L ‐Lysine‐HCl was added to the basal diet to yield five and six treatments in the two experiments. Diets in the first experiment were determined to contain 9.2, 14.1, 14.6, 19.9 and 21.0 g available lysine kg^?1 on a dry‐matter basis. Diets in the second experiment were determined to contain 14.8, 18.1, 21.3, 24.5, 27.6 and 30.9 g available lysine kg^?1 on a dry‐matter basis. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and apparent nitrogen utilization (ANU) were significantly (P < 0.05) improved by increasing dietary lysine concentrations to approximately 20 g kg^?1 of diet. Least‐squares regression analysis of weight gain and SGR in the first experiment indicated a minimum dietary lysine requirement of 20.1 ± 2 g kg^?1 dry diet. Least‐squares regression analysis of the same criteria measured in the second experiment yielded the following estimates of dietary lysine requirements (g kg^?1 dry diet): 19.8 ± 2.3 for weight gain, 21.7 ± 1.5 for SGR, 23.7 ± 3.5 for FCR and 18.6 ± 1.3 for ANU. From these results the minimum recommended dietary lysine requirement for optimal growth of juvenile striped bass is approximately 21 g kg^?1 dry diet which equates to 49 g kg^?1 dietary protein or 1.57 mg kJ^?1 DE. Although higher than that reported for hybrid striped bass, this requirement level is similar to those reported for many other fish species.     

Age-Related Sperm Quality of Captive Striped Bass Morone saxatilis

Three groups of captive-reared striped bass Morone saxatilis ages 1, 3 and 12 yr, were examined for age-related changes of sperm characteristics including short-term storage. All groups had similar ranges of the following parameters (mean× SEM): expressible milt (5.6× 0.5 mI/kg body weight (BW) to 7.5× 2.1 mL/kg BW), percentage of motile sperm (55× 6% to 60× 2%), duration of sperm motility (69× 3 sec to 72× 5 sec) and percentage of viable sperm (91× 2% to 93× 2%). Compared to the 1 and 12-yr-old fish, the 3-yr-old fish produced the greatest number of spermatozoa (1,190× 370× 10⁹ spermatozoa/kg), sperm concentration (120× 8 × 10⁹ spermatozoa/mL) and spermatocrit (74× 4%). In addition, during short-term storage at 4 C, extender-preserved sperm samples of the 3-yr-old group showed a significantly higher ( P < 0.05) percentage of motile sperm and duration of sperm motility, compared to the other two groups. This suggests that short-term storage may be affected by the age of the male fish. Sperm longevity of the 3-yr-old group was successfully maintained for as long as 15 d, longer than that of the 1-yr-old group (9 d) and 12-yr-old group (7 d). Overall, the 3-yr-old fish appeared to have superior sperm quality than the 1 or 12-yr-old fish based on higher sperm production and increased sperm longevity.     

Non-destructive measurement of sunshine bass, Morone chrysops (Rafinesque) ×Morone saxatilis (Walbaum), body composition using electrical conductivity

Abstract. We describe a rapid, non-destructive method for determining lean body mass (LBM; i.e. total body mass — total lipid mass) and lipid content in live fish. This method provides non-invasive determination of body composition by measuring the total body electrical conductivity (TOBEC) of an animal placed within a low-frequency electromagnetic field. This principle is governed by the different electrical properties of body fat and fat-free tissues. Relationships between TOBEC analysis and body composition were examined using juvenile sunshine bass (hybrid striped bass, Morone chrysops (Rafinesque) ♀× M. saxatilis (Walbaum) ♂) in a size range of 24–124g. Whole-body conductivity was significantly correlated to LBM, lipid, protein, water, and ash content. Analyses of an independent group of fish indicated TOBEC to be a reliable indicator of body composition. This method should prove useful for deriving body composition data at various phases of an experiment or a life cycle, rather than a single point in time as with destructive methods.     

Dietary Zinc Requirement of Hybrid Striped Bass,Morone chrysops×Morone saxatilis,and Bioavailability of Two Chemically Different Zinc Compounds

Zinc is a trace mineral element that plays an essential role in numerous biochemical processes, and has been shown to affect growth and health of several fish species. However, the dietary zinc requirement of hybrid striped bass has not been defined. Therefore, a feeding trial was conducted to determine the dietary requirement for zinc by this fish and to compare zinc bioavailability of two chemically different forms (zinc sulfate and zinc proteinate). Six experimental diets were formulated with purified ingredients and supplemented with ZnSO₄ to provide total zinc concentrations of 7, 12, 16, 26, 42, and 80 mg/kg diet which were determined by analysis. Each diet contained 32% crude protein, 6% lipid, and approximately 14.2 kJ of digestible energy per gram. The experimental diets were fed twice daily for 10 wk to triplicate groups of 15 hybrid striped bass initially weighing 0.86 ± 0.05 g/fish in 38‐L glass aquaria, connected as a recirculating system. Finally, after the feeding period, the fish were evaluated for weight gain, feed efficiency, protein efficiency ratio, and survival, as well as blood serum zinc, bone zinc, and hematocrit. All fish thrived during the feeding trial and not even the fish fed the basal diet displayed any apparent deficiency signs, although weight gain steadily increased with escalating levels of dietary zinc up to 42 mg/kg diet. On the basis of the most responsive indicators–bone zinc and serum zinc–the minimum dietary zinc requirement of hybrid striped bass was determined to be 17.0 and 17.3 mg Zn/kg diet, respectively, based on broken‐line regression. This estimate is similar in magnitude to dietary zinc requirements reported for other fish species. In addition, the bioavailability of zinc proteinate versus that of ZnSO₄ was estimated by deriving the ratio of the slopes of the regression lines fitted to bone zinc and serum zinc data. This analysis indicated that hybrid striped bass utilized zinc proteinate ～1.7 times more efficiently than ZnSO₄.     

Quantitative Dietary Threonine Requirement of Juvenile Striped Bass Morone saxatilis

A 10-wk feeding trial was conducted to quantify the dietary threonine requirement of juvenile striped bass Morone saxatilis . The basal diet was analyzed to contain 42% crude protein with a calculated digestible energy (DE) level of 3,200 kcal/kg. L-threonine was added to the basal diet to yield five dietary treatments of 0.61, 0.81, 1.00, 1.18, and 1.40% available threonine on a dry-matter basis. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR) and apparent nitrogen utilization (ANU) were significantly ( P < 0.05) affected by dietary threonine concentrations. Least-squares regression analysis of weight gain, SGR, FCR, and ANU indicated dietary threonine requirements (±SE) of 1.00 ± 0.19, 0.91 ± 0.11, 1.06 ± 0.09 and 1.13 ± 0.22% of dry diet, respectively. From these results, the average recommended dietary threonine requirement of juvenile striped bass is 1.03% of dry diet, 2.45% of dietary protein or 3.22 mg/kcal DE.     

Larval Rearing and Weaning Techniques for White Bass Morone chrysops

The effects of culture parameters of tank color and feeding regimes were examined on larval white bass Morone chrysops during 1994–1995. Under high surface illumination (998 lux), dark tank walls were essential for effective prey capture. Larvae reared in clear glass aquaria did not grow and had died by day 6 of the study. In contrast, 48.7% of the larvae reared in black-walled tanks were alive on day 24 and had grown to 17.2 mm total length (TL). In another study, larvae were fed rotifers Brachionus plicatilis and Artemia nauplii in different feeding protocols. In one treatment only rotifers (10/mL) were fed day 1 (4 d post-hatch), rotifers and Artemia (3/mL) were fed days 2–4, and Artemia fed days 5–15. This protocol produced similar growth (mean size 11.7 mm TL) and survival (mean 30.3%) as slower weaning times from rotifers to Artemia . Juveniles (27-day-old, 17.2 mm TL) were converted to a dry crumble diet over a 14-d period by slow transfer from a combination diet consisting of live Artemia nauplii, frozen adult Artemia , plankton flakes and dry crumbles. Survival offish weaned to the dry diet was 64.5%. Most of the mortalities during the weaning period were fish with uninflated swim bladders which were cannibalized by larger fish. Using the above tank culture techniques, white bass were reared to a mean size of 73.2 mm TL (mean weight 5.8 g) over a 73-d period. This essentially closes the life cycle of white bass.     

The Annual Reproductive Cycle of the White Bass Morone chrysops

The gametogenic cycle of the white bass Moronc chrysops was characterized for one year at monthly intervals by measuring circulating levels of the sex steroid hormones testosterone (T) and 11-ketotestosterone (11-KT) in males, and 17β-estradiol (E₂) and T in females. Vitellogenin (VTG), the egg yolk precursor, was also measured in female blood plasma. Gonadal status of individual fish was assessed by histological evaluation, measurement of oocyte diameters, and spermintion response. At the onset of vitellogenesis (October), blood plasma levels of E₂ and T were low, but increased significantly as the spawning period (March-April) approached and oocytes attnined their maximum diameter. All stages of oocyte development were observed in mature females, indicating that the white bass is a multiple-clutch, groupsynchronous spawner. Androgen levels increased in males throughout the reproductive cycle and reached maximal levels during the spawning period. The increase in androgens coincided with sperm production and spermintion in males. The circannual endocrine and gonadal development patterns observed in white bass were similar to those of other members of genus Moronc .