Petersen Petra E, Penman David J, Dahle Geir, Patursson Øystein, Taggart John B
Department of Biotechnology, Aquaculture Research Station of the Faroes, við Áir, Hvalvík, Faroe Islands.
Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, Scotland.
PLoS One. 2016 Jun 30;11(6):e0158091. doi: 10.1371/journal.pone.0158091. eCollection 2016.
Aquaculture production of cod has decreased from over 20,000 tonnes in 2009 to less than 2,000 tonnes in 2014 and the industry faces many challenges, one of which is high and unpredictably variable mortality rates in the early life stages. Hence, full-cycle farming with hatchery produced juveniles is still considered unprofitable compared to fisheries and on-growing of wild cod. In the present study, potential batch differences in progeny survival of wild-caught, hatchery-spawned Faroe Bank cod (Gadus morhua L.) were investigated at two defined periods during early life history; i) the embryo stage (60 day degrees post fertilisation) and ii) the fry stage (110 days post hatch), post metamorphosis. The fry stage experiment was conducted in three replicates (N = 300 per replicate), and a panel of three polymorphic microsatellite markers was used for parental analysis. Mean survival rate at the embryo stage was 69% (± 20% SD). Survival was positively associated with egg diameter (P < 0.01), explaining 90% of the variation in egg survival rates. The data were too scarce to conclude either way concerning a possible correlation between survival rates between the two periods (P < 0.10). Offspring from three batches (from a total of eight) dominated in the fry stage, contributing over 90% of the progeny, and results were consistent over all three replicate tanks. The skewed batch representation observed may be of relevance to the effective management of selective breeding programmes for cod.
鳕鱼的水产养殖产量已从2009年的20000多吨降至2014年的不足2000吨，该行业面临诸多挑战，其中之一是幼鱼早期阶段的死亡率高且变化无常。因此，与渔业以及野生鳕鱼的养殖相比，使用孵化场培育的幼鱼进行全周期养殖仍被认为无利可图。在本研究中，对野生捕捞、孵化场繁殖的法罗浅滩鳕鱼（Gadus morhua L.）后代在早期生命史的两个特定阶段的潜在批次差异进行了调查；i）胚胎阶段（受精后60度日）和ii）幼鱼阶段（孵化后110天，变态后）。幼鱼阶段的实验进行了三次重复（每个重复N = 300），并使用一组三个多态性微卫星标记进行亲本分析。胚胎阶段的平均存活率为69%（±20%标准差）。存活率与卵径呈正相关（P < 0.01），解释了卵存活率变化的90%。数据过于稀少，无法就两个阶段的存活率之间可能的相关性得出结论（P < 0.10）。在幼鱼阶段，三批（总共八批）的后代占主导地位，贡献了超过90%的子代，并且在所有三个重复水箱中的结果都是一致的。观察到的批次代表性偏差可能与鳕鱼选择性育种计划的有效管理相关。
