Metamorphosis in summer flounder: manipulation of rearing salinity to synchronize settling behavior, growth and development
Metamorphosis in summer flounder: manipulation of rearing salinity to synchronize settling behavior, growth and development
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夏季比目鱼的变态：控制饲养盐度以同步沉降行为、生长和发育
DOI：
10.1016/j.aquaculture.2004.07.007
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发表时间：
2004
期刊：
影响因子：
4.5
通讯作者：
J. Specker
中科院分区：
文献类型：
--
作者：
Steven Gavlik;J. Specker
在夏鲽（Paralichthys dentatus）的水产养殖中，变态过程中生长和沉降行为的固有变化可能会导致同类相食，并且由于尺寸分级而需要增加劳动力。我们的目标是利用环境盐度变化作为同步沉降行为的线索，并产生更大、尺寸更均匀的幼年比目鱼群体。早期变质比目鱼暴露于饲养盐度的 5 天波动（30-20-30-20-30 ppt；“通量”）或单次（30-20 ppt；“20 ppt”）下降。使用对照（连续 30 ppt）进行比较。峰值沉降间隔的平均值（PSI；定义为从前 20% 沉降之日开始到 80% 沉降之日的间隔）不受盐度操纵的影响，尽管 20 ppt 处理确实使每天的沉降百分比显着增加了 54 dah。与对照组（17.6±0.5 毫米）相比，20-ppt 处理组（19.3±0.5 毫米）增加了鱼的平均大小，但通量处理组（17.2±0.4 毫米）没有增加。与 Flux (2.9±0.1) 相比，20-ppt 处理 (3.2±0.1) 的发育阶段显着增加，但对照 (3.1±0.1) 则没有。然而，20 ppt 处理减少了发育差异。为了确认 20-ppt 治疗的积极效果，进行了第二次实验。单次盐度下降（“20 ppt”）、先前的成功（[Gavlik, S.、Albino, M.、Specker, J.L., 2002。夏季比目鱼的变态：操纵甲状腺状态以同步沉降行为、生长和发育。水产养殖 203 (3-4), 359-373]甲状腺激素操纵治疗（“TH”）以及两者的组合（“TH+20 ppt”）与对照（连续 30 ppt，无甲状腺操作）相比，TH（7±1 天）和 TH+20 ppt（8±0 天）治疗的平均 PSI 显着降低，而 20 ppt 治疗（9±0 天）的 PSI 与对照相比没有显着差异。暴露于 20 ppt 盐度的比目鱼比 30 中的比目鱼更大（20 ppt：18.6±0.3 mm；TH+20 ppt：18.3±0.3 mm）且发育更先进（20 ppt：3.1±0.04；TH+20 ppt：3.2±0.03）。 ppt（TH：17.8±0.3 mm/3.1±0.3；对照：17.9±0.3 mm/3.0±0.05）最后，20-ppt 处理减少了生长和发育的方差。总之，在两个实验中，饲养盐度从 30 ppt 降低到 20 ppt，增加了生长、沉降行为和发育。养殖盐度的降低与 TH 操作相结合，应该会产生更大、尺寸更均匀的比目鱼群体，我们预计这种同步将减少与养殖的变态夏季比目鱼尺寸分级相关的同类相食和劳动力成本。
In the aquaculture of summer flounder (Paralichthys dentatus), the inherent variation in growth and settling behavior during metamorphosis may lead to cannibalism and necessitate increased labor due to size grading. Our goal was to use an environmental salinity change as a cue to synchronize settling behavior and produce a larger, more uniformly sized cohort of juvenile summer flounder. Early metamorphic flounder were exposed to either a 5-day fluctuating (30–20–30–20–30 ppt; “Flux”) or a single (30–20 ppt; “20 ppt”) drop in rearing salinity. A control (continuous 30 ppt) was used for comparison. Average values for a peak settlement interval (PSI; defined as the interval beginning on the day by which the first 20% had settled until the day 80% had settled) were not affected by salinity manipulation, though the 20-ppt treatment did significantly increase percent settled per day by 54 dah. Average fish size was increased by the 20-ppt treatment (19.3±0.5 mm), but not the flux treatment (17.2±0.4 mm), compared to the control (17.6±0.5 mm). Developmental stage was significantly increased in the 20-ppt treatment (3.2±0.1) in comparison to the Flux (2.9±0.1), but not the control (3.1±0.1). However, the 20-ppt treatment reduced variance in development. To confirm the positive effects of the 20-ppt treatment, a second experiment was performed. A single salinity drop (“20 ppt”), a previously successful ([Gavlik, S., Albino, M., Specker, J.L., 2002. Metamorphosis in summer flounder: Manipulation of thyoid status to synchronize settling behavior, growth, and development. Aquaculture 203 (3-4), 359-373]thyroid hormone manipulation treatment (“TH”) and a combination of the two (“TH+20 ppt”) were compared to a control (continuous 30 ppt, no thyroid manipulation). The mean PSI was significantly reduced by both TH (7±1 days) and TH+20 ppt (8±0 days) treatments, compared to the control (11±1 days). The PSI for the 20-ppt treatment (9±0 days) was not significantly different than the control. The percent flounder settled per day was significantly increased by 20 ppt salinity and significantly modified (decreased, then increased) by TH manipulation. Flounder exposed to 20-ppt salinity were both larger (20 ppt: 18.6±0.3 mm; TH+20 ppt: 18.3±0.3 mm) and more developmentally advanced (20 ppt: 3.1±0.04; TH+20 ppt: 3.2±0.03) than flounder in 30 ppt (TH: 17.8±0.3 mm/3.1±0.3; Control: 17.9±0.3 mm/3.0±0.05). Finally, 20-ppt treatment reduced variance in development, while TH treatment reduced variance in both growth and development. Percent survival was unaffected by treatment in both experiments. In summary, a decrease in rearing salinity, from 30 to 20 ppt, increased growth, settling behavior and development of metamorphosing summer flounder. A decrease in rearing salinity, in combination with a TH manipulation, should result in larger, more uniformly sized flounder cohorts. We expect this synchronization will reduce the cannibalism and labor costs associated with size grading of cultured, metamorphosing summer flounder.
影响因子：
4.5
作者：
Shuozeng Dou;T. Seikai;K. Tsukamoto
通讯作者：
Shuozeng Dou;T. Seikai;K. Tsukamoto
影响因子：
4.5
作者：
Shuozeng Dou;R. Masuda;Masaru Tanaka;K. Tsukamoto
通讯作者：
Shuozeng Dou;R. Masuda;Masaru Tanaka;K. Tsukamoto