稚鲍饵料的初步试验

在鲍鱼人工育苗过程中，解决稚鲍的适宜饵料及满足供应的问题是充分发挥幼体的生长发育潜力，提高成活率的关键。如何解决稚鲍饵料问题，国内外曾有一些报道。如福建省东山鲍珠站的措施是：5mm以内的稚鲍，主要靠附着板上事先培养的底栖硅藻，其后以更换附着片进行饵料的补充。5mm以上幼鲍主要投喂海藻及人工配合饵料片。日本在5mm以下幼鲍期，主要也是靠底栖硅藻类及海带，     

不同饵料对中国对虾幼虾生长及感染WSSV存活率的影响

采用4种饵料投喂中国对虾（Fenneropenaeus chinensis）幼虾，用投喂感染的方法人工感染WSSV。测定体长、体重以及各组的攻毒存活率，实验周期15d。ANOVA分析结果表明，投喂鲜活卤虫组体长、体重的增长明显优于其他各组，差异达极显著水平（P〈0．01）；投喂人工配合饵料实验组的体长、体重增长量最小；投喂鱼肉组体长增长慢于投喂蛤蜊肉组，而体重的增长快于投喂蛤蜊肉组，差异均不显著（P〉0．05）。投喂卤虫成体和投喂鱼肉两组的攻毒存活率最高，明显高于投喂配合饵料和蛤蜊肉两实验组，差异达极显著水平（P〈0．01）；投喂卤虫组和投喂鱼肉组之间存活率无显著差异（P〉0．05），投喂人工配合饵料组和蛤蜊肉组差异不显著（P〉0．05）。巢式PCR检测表明，人工感染前的中国对虾幼虾少数携带WSSV，人工感染后全部个体检测到病毒特征片段。     

控温快速养殖中华鳖技术的研究

利用玻璃温室采光加温和塑料大棚采光增温两种方式,分别在越冬前和越冬后进行稚鳖和幼鳖养殖,投喂全价配合饲料,结果：稚鳖经１００天的饲养,平均体重从３—５ｇ长到７２．２５ｇ,平均日增重０．６８ｇ／只,饵料系数为１．３０,成活率９４．６６％,单产为１．２９ｋｇ／ｍ２,幼鳖经７３天饲养,平均体重从７２．２５ｇ长到２５１．５７ｇ,平均日增重为２．４６ｇ／只,饵料系数１．２６,成活率９７．３２％,单产３．１２ｋｇ／ｍ２。此种养殖方式,为北方地区人工快速养鳖,探索了一条有效途径。     

不同人工饵料对方斑东风螺幼虫生长及存活的影响

在温度(28.7±0.5)℃、盐度29.0±0.3条件下,研究虾片、黑粒、螺旋藻粉3种人工饵料单独投喂及与虾元和B.P.饵料添加剂混合投喂14d后对方斑东风螺幼虫生长及存活的影响。结果表明,人工饵料与添加剂混合投喂时幼虫的存活率、壳高、壳长及特定生长率高于单一投喂试验组。混合投喂组中以螺旋藻粉+B.P.组的效果最好。在单一人工饵料试验组中,投喂3种人工饵料的方斑东风螺幼虫在试验初期生长差异不显著,但投喂螺旋藻粉的存活率明显高于单独投喂虾片与黑粒组(P0.05);试验后期单独投喂黑粒的幼虫特定生长率及存活率最高,其次为虾片,单独投喂螺旋藻粉的幼虫特定生长率及存活率最低。研究结果可为方斑东风螺幼虫人工配合饲料的开发及人工苗种培育提供参考依据。     

不同方式加工海带投喂盘鲍幼鲍生长速度比较

将初始壳长1.890.20cm的盘鲍幼鲍随机分配到3个试验组,每组50只,每个试验组各设4个平行组。第1组:投喂盐渍海带;第2组:投喂煮沸海带;第3组(对照组):投喂晒干海带。试验用鲍在同一口水泥池中饲养50d,投喂足量饵料。投喂盐渍海带盘鲍幼鲍的日均壳长增长(P<0.001)及平体重增长率(P<0.05)均明显高于对照组,但投喂煮沸海带盘鲍幼鲍的日均壳长增(P>0.05)及平均体重增长率(P>0.05)与对照组无明显差异。     

投喂不同蛋白含量饲料对黄喉拟水龟生长的影响

正近年来,黄喉拟水龟逐步从传统的小型养殖转变为规模化养殖,而养殖过程中所用饲料多为养殖者自行配置,其营养成分未必适合不同的龟。为降低养殖成本,提高养殖的经济效益,本试验通过对龟碌(两广地区对亚成体龟的叫法,体重在200g～500g)投喂蛋白含量分别为38%、40%、42%和44%的配合饲料,定期测量龟碌体重,计算其增重率及饵料系数。结果表明,投喂蛋白含量为42%的组平均增重为105g,增重率达52.5%,饵料系数为1.73;投喂投喂蛋白含量为38%的组平均增重62.5g,增重率为31.3%,饵料系数为2.53。试验结果得出了黄喉拟水龟龟碌阶段的最佳营养需求,为黄喉拟水龟产业健康可持续发展提供了依据。     

皱纹盘鲍的底播增殖试验

1987～1990年在长海县獐子岛近海水域,采用人工培育的平均壳长为20mm(12～34mm)的幼鲍进行底播,3周年后,平均壳长达77.5mm,平均体重达64.7g,成活率为46.9%。试验证明,底播幼鲍的规格与其成活率密切相关,适宜规格为壳长20～25mm,最小规格为18mm。讨论了回捕率的调查方法,以及幼鲍底播规格与中间育成在时间上的衔接等问题。     

福建沿海皱纹盘鲍人工育苗技术研究

在福建沿海,皱纹盘鲍秋季人工育苗效果明显优于春季育苗.采取异地引进亲鲍、用面积1 m2的透明塑料薄膜培养硅藻饵料并用于采苗,薄膜投放密度14片/m2,担轮幼体布池密度10×104～15×104个/m2等技术措施,匍匐幼体平均采集密度200～300个/片,稚鲍的前期培育时间可延长至44 d,剥离规格达4.64 mm;稚鲍剥离至池底水泥板上进行继续培育,培育密度2000～2500个/m2,至壳长10 mm时成活率可达79%;平均单位面积出苗量1200个/m2.     

皱纹盘鲍工厂化育苗技术

利用坑道培育和海捕的皱纹盘鲍亲体，进行人工催产、授精；以高密度集中培育浮游幼虫；用以舟形藻、卵形藻和菱形藻为主的底栖硅藻作为开口饵料，进行稚鲍前期培育；以幼鲍专用饲料作稚鲍后期饵料，进行稚鲍后期流水平面培育。1996年在8m2的采苗水面培育出壳长1．0～1．2cm的稚鲍2．4万个；1997年在50m2的采苗水面培育出壳长1．0～1．7cm的幼鲍16万个。     

怎样提高稚参成活率

１控制培育密度 适宜的培育密度,不仅可提高稚参成活率和参苗质量,而且能加快稚参的生长速度。适宜的密度为０．２～０．４头／ｃｍ２,这个密度再加上管理措施得当,成活率可达５０％以上。２饵料要质好量足 刚变态的稚参,体长在 ０． ２ ｃｍ之前,饵料以底栖硅藻为主,适当投喂海滩表泥及浮泥,增喂一些单细胞藻类沉淀液。稚参体长达到 ０． ２ ｃｍ以后,饵料以鼠尾藻粉为主,日投２～３次,日投量５０～８０Ｘ １０－６。随着体长增长,每 ３～４日加喂一次含蛋白质较高的人工配合饵料。３加强水质管理 采用流水法培育稚参,可保持…     

Dietary value of gametophytes and juvenile sporophytes of the brown macroalga <Emphasis Type="Italic">Eisenia bicyclis</Emphasis> for juvenile abalone <Emphasis Type="Italic">Haliotis diversicolor</Emphasis>

The dietary value of juvenile stages (gametophyte and juvenile sporophyte) of the brown macroalga Eisenia bicyclis for post-larval and juvenile abalone Haliotis diversicolor of 2.0–6.5 mm in shell length (SL) was examined and compared with that of a benthic diatom, Nitzschia sp., in laboratory experiments. Most abalone actively fed on these diets, but there were large variations in the growth rate among the diets and among the growth stages of abalone. Growth rates of abalone fed on Nitzschia sp. were highly variable within each growth stage, but showed no clear differences among growth stages. In contrast, in abalone fed gametophytes or juvenile sporophytes, growth rates linearly increased as abalone grew. Growth rates of >60 μm SL/day were observed in juveniles of >3 mm SL fed gametophytes, and juveniles of >5 mm SL fed juvenile sporophytes. These results indicate that the dietary value of the juvenile stages of E. bicyclis for the abalone changes as they grow, and with growth juvenile abalone begin to efficiently utilize gametophytes and juvenile sporophytes in that order.     

Growth of 0-group turbot (Scophthalmus maximus L. 1758) fed on artificial diets

Group-0 turbot Scophthalmus maximus L. were fed on artificial diets for 13 months, at 15° C. Partially defined diets containing about 40% protein were used and fish were fed once per day with moist pellets.The mean weight of the fish, at the beginning of the experiment, was 3.5 g. During the first 6 months, a fish gained 15 g weight on average, and 40 g in the following 6 months. The final mean weight was 62 g, and the final mean total length, 15.3 cm. The daily growth rate was 0.7% and the protein efficiency ratio (P.E.R.) ranged between 1.4 and 2.1.For fish fed on natural food at 15° C, the results were similar for the first 9 months. Subsequently, these fish grew faster than those fed artificial diets.     

Effect of dietary substitution of sea tangle (ST), Laminaria japonica with rice bran (RB) on growth and body composition of juvenile abalone (Haliotis discus)

Dietary substitution effect of sea tangle (ST) with rice bran (RB) on growth and carcass composition of juvenile abalone (Haliotis discus) was determined. Juvenile abalone was acclimated to the experimental conditions for 4 weeks. Seventy juvenile abalone averaging 0.43 g were randomly distributed into each of the 18, 70 L plastic rectangular containers. The experimental diets were fed to abalone once a day at a satiation level with a little leftover. The feeding trial lasted for 16 weeks. Survival of abalone was not affected by dietary substitution of ST with RB. However, weight gain of abalone fed the RB40 diet was higher than that of abalone fed the all other diets except for the RB0 diet. No significant difference in weight gain was found in abalone fed between the RB0 and RB100 diets. SGR of abalone fed the RB40 diet was higher than that of abalone fed the all other diets. Also SGR of abalone fed the RB0 diet was higher than that of abalone fed the RB100 diet, but not different from that of abalone fed the RB20, RB60 and RB80 diets. Moisture, crude protein and ash content of the soft body of abalone were affected by dietary substitution of ST with RB. In conclusion, the 100% ST could be substituted with RB without a retardation of weight gain of abalone when the 20% ST was included into the experimental diet. However, the best growth performance was obtained in abalone fed the RB40 diet substituting 40% ST with RB.     

Radula development in abalone Haliotis discus hannai from larva to adult in relation to feeding transitions

ABSTRACT: The radula morphology of Haliotis discus hannai was examined by scanning electron microscope from the larval to the adult stage. The radula of competent larvae contained 11–13 transverse rows of teeth after 6–7 days at 20°C. The number of rows increased to 25–30 during the first several days after settlement, but then remained approximately constant throughout the post-larval period, increasing again in abalone larger than 4 mm in shell length (SL). In post-larvae < ~1 mm SL, only two pairs of lateral teeth (L1, L2) were present in the larval radula. An additional three pairs of lateral teeth (L3–L5) were added progressively as post-larvae grew from 0.9 mm to 1.9 mm SL. Marginal teeth were added steadily from one pair in larvae to 30–40 pairs at 3–4 mm SL, 70–80 pairs in 30–40 mm juveniles, and 70–90 pairs in 90–100 mm adults. The serrations on the working edges of the rachidian (R) and lateral teeth became less pronounced as the abalone grew. Nearly all serrations disappeared from the rachidian (R) and inner lateral teeth (L1, L2) by ~2 mm SL, and from the outer lateral teeth (L3–L5) by 20 mm SL. For abalone larger than 1.5 mm SL, the L3–L5 teeth became longer and more pointed, which increased the space between adjacent rows of teeth. Post-larvae < 1 mm SL had highly curved teeth with clearance angles of approximately or less than zero, whereas larger abalone had positive clearance angles. These radula developments appear to be related to transitions in feeding habits from microbial to macroalgal diets.     

Shell marking by artificial feeding of the tropical abalone Haliotis asinina Linne juveniles for sea ranching and stock enhancement

A method of marking abalone (Haliotis asinina Linne) for sea ranching and stock enhancement purposes was developed. Three‐month‐old abalone juveniles (11.8‐mm shell length, 0.28 g) were fed artificial diets for 1, 2, or 3 weeks. The width of the bluish‐green shell band produced by abalone juveniles was 1.7, 2.6, and 4.2 mm after 1, 2, or 3 weeks of feeding respectively. The growth and survival of juveniles fed artificial diets did not differ from that of juveniles fed the seaweed Gracilariopsis bailinae (control). Feeding the diet‐fed juveniles with the seaweed thereafter produced the natural brownish shell, thus forming a sandwiched bluish‐green band. An experimental release in outdoor tanks with natural growth of seaweeds and diatoms, and in a marine reserve showed that the shell band remained clear and distinct, indicating the usefulness of this shell marking method in sea ranching and stock enhancement of abalone.     

Growth performance and the soft body composition of juvenile abalone,Haliotis discus,Reeve 1846, fed the extruded pellets substituting fish meal and macroalgae with tunic meal of sea squirt,Halocynthia roretzi

Growth performance and the soft body composition of juvenile abalone fed the extruded pellets (EPs) substituting fish meal (FM) and macroalgae (MA) with tunic meal of sea squirt (SS) was investigated. A total of 1,260 abalone were distributed into 18 containers. Six experimental diets were prepared in triplicate. Five diets were pelletized by an extruder pelleter. The 140 g/kg FM and 250 g/kg mixture of MA were included into the control (Con) diet. Five hundred and 1,000 g/kg of each FM and MA were substituted with an equal amount of tunic meal of SS, referred to as the FM50, FM0, MA50 and MA0 diets, respectively. Finally, dry Undaria pinnatifida was prepared. Weight gain and specific growth rate of abalone fed all EPs were greater than those fed U. pinnatifida. Weight gain of abalone fed MA50 and FM50 diets was greater than Con and FM0 diets, but not different from MA0 diet. Higher crude protein and lipid contents were observed in soft body of abalone fed all EPs compared to U. pinnatifida. In conclusion, FM and MA up to 500 and 1,000 g/kg, respectively, could be replaced with tunic meal of SS in EPs without retardation in growth of abalone.     

Effects of oxygen supersaturation and temperature on juvenile greenlip, Haliotis laevigata Donovan, and blacklip, Haliotis rubra Leach, abalone

Growth and survival of juvenile greenlip (39.03 (SD 3.80) mm (n=524)) and blacklip (31.92 (SD 4.19) mm (n=531) abalone were investigated at high dissolved oxygen levels (95–120% saturation) between 17 and 19°C. Abalone were fed the same artificial diet and each species was contained in groups of approximately 30 individuals within triplicate tanks for each of six treatments and were exposed to flow through water adjusted to give experimental conditions for up to 75 days. Blacklip abalone held at 16.9°C and 97% oxygen saturation grew in shell length significantly faster than all other treatments of blacklip abalone held at 19°C, and significantly faster than blacklip abalone maintained at 111% oxygen saturation and 17.5°C. Both temperature and oxygen saturation significantly affected the survival of this species. Blacklip abalone held at 19°C had significantly lower survival for both 96% oxygen saturation and 120% oxygen saturation, compared with blacklip abalone maintained at either 110% oxygen saturation and 19°C, or for any 17°C treatment. No significant differences were noted for greenlip abalone within the range tested in terms of growth rate, food consumption rate or survival, indicating that greenlip abalone tolerated these conditions better than did blacklip abalone.     

Substitution effect of sea tangle (ST) (Laminaria japonica) with tunic of sea squirt (SS) (Halocynthia roretzi) in diet on growth and carcass composition of juvenile abalone (Haliotis discus,Reeve 1846)

Substitution effect of sea tangle (ST) with tunic of sea squirt (SS) in diet on growth and carcass composition of juvenile abalone was determined. One thousand four hundred and seventy abalones were distributed into 21 containers. Six formulated diets in triplicate were prepared. A 200 g/kg ST was included into the ST0 diet. The 200, 400, 600, 800 and 1000 g/kg of ST were substituted with the same amount of tunic of SS, referred to as the ST200, ST400, ST600, ST800 and ST1000 diets, respectively. Finally, Undaria was prepared to compare effect of the formulated diets on performance of abalone. The experimental diets were fed to abalone for 16 weeks. Weight gain of abalone fed the ST400 diet was higher than that of abalone fed the ST0, ST600, ST800 and ST1000 diets and Undaria. Weight gain of abalone fed the formulated diets was higher than that of abalone fed the Undaria. The chemical composition of the carcass of abalone was affected by dietary substitution of ST with tunic of SS. In conclusion, ST could be completely substituted with tunic of SS without retardation in performance of abalone. Abalone fed the ST400 diet substituting 400 g/kg ST with tunic of SS achieved the best growth.     

GROWTH OF WHITE STURGEON (Acipenser transmontanus) UNDER HATCHERY CONDITIONS

White sturgeon juveniles were raised for 10 months posthatch under various regimens of feeding, water temperature, and stocking density. Transition to external feeding in larvae occurred 9 to 11 days posthatch and was accompanied by major changes in allometric growth and larval behavior. Condition factor, hepatosomatic index, and survival rate varied significantly throughout the rearing period in the 4 progenies investigated. Growth in body weight for all progenies was largely dependent on water temperature and feeding. On the average, fingerlings raised on natural diets (brine shrimp and tubifex, followed by ground fish) grew 6% of their body weight per day, whereas fingerlings fed artificial pelleted diets (Oregon Moist Pellets) or a mixture of pelleted and natural feeds grew 1–4% per day. Certain individuals (20% of population investigated), however, established a strong feeding performance on artificial diets and exhibited twice the growth rate of fish raised on natural diets; these fish reached a mean body weight of 282 g at 10 months post-hatch. Assuming more efficient procedures are developed for weaning this fish onto artificial diets, the white sturgeon has demonstrated a potential for use in intensive grow-out systems.     

Substitution effect of Undaria pinnatifida with citrus (Citrus unshiu,Marcovitch) peel by‐product in feed on the growth,body composition and air exposure stressor of juvenile abalone (Haliotis discus,Reeve 1846)

Substitution effect of Undaria pinnatifida with citrus peel by‐product (CPB) on growth, body composition and air exposure stressor of abalone was determined. A total of 1,080 abalone were distributed into 18 net cages. Five formulated diets were prepared in triplicate. The CPB0 diet contained 200 g/kg U. pinnatifida. The 250, 500, 750 and 1,000 g/kg U. pinnatifida were substituted with the equal amount of CPB, referred to as the CPB250, CPB500, CPB750 and CPB1000 diets, respectively. Finally, dry U. pinnatifida was prepared. Abalone were fed for 16 weeks and then subjected to air exposure stressor for 24 hr. The cumulative mortality of abalone was monitored for the following 4 days after 24‐hr air exposure. Survival, weight gain and specific growth rate (SGR) of abalone fed all formulated diets were greater than those of abalone fed the U. pinnatifida. The greatest weight gain and SGR were achieved in abalone fed the CPB500 diet. The chemical composition of the soft body of abalone was not affected by the experimental diets. Higher cumulative mortality was observed in abalone fed the CPB0 and dry U. pinnatifida at 16 hr after 24‐hr air exposure compared to abalone fed all other diets. In conclusion, U. pinnatifida could be completely substituted with CPB in abalone feed.