Neal J Wesley, Eggleton Michael A, Goodwin Andrew E
Department of Wildlife and Fisheries, Mississippi State, MS 39762-9690, USA.
J Wildl Dis. 2009 Jul;45(3):766-71. doi: 10.7589/0090-3558-45.3.766.
A 22.4-ha impoundment experienced an outbreak of Largemouth bass (Micropterus salmoides) virus (LMBV) disease in the summer of 2006. All dead or dying largemouth bass observed throughout the entire event were recorded and removed. In this study, we estimated mortality and examined size distribution, condition, and biomass following the outbreak. Boat-mounted electrofishing was used to collect largemouth bass for a mark-recapture population estimate and other population metrics. Fish samples were examined for evidence of LMBV, other infectious diseases, and physical abnormalities. Cell cultures inoculated with samples from moribund fish developed cytopathic effects typical of LMBV, and polymerase chain reaction (PCR) confirmed the presence of LMBV. The total number (N+/-95% confidence interval) of stock-size largemouth bass remaining was estimated to be 2,301+/-528 fish (103 bass/ha). The total observed mortality, including dead and dying individuals, during the LMBV outbreak was 176 largemouth bass (7% of the initial population). The total biomass remaining was estimated at 1,592 kg of stock-size bass and a relative biomass of 71.5 kg of stock-size largemouth bass per hectare. Largemouth bass size structure was dominated by quality and preferred (300-510 mm) size classes, with very few memorable-size or larger (>510 mm) fish, and the relative weight of largemouth bass was unusually variable. These results demonstrate that largemouth bass abundance and biomass in the reservoir remained very high despite mortalities attributed to a LMBV outbreak.
2006年夏天，一个面积为22.4公顷的蓄水池爆发了大口黑鲈（Micropterus salmoides）病毒（LMBV）病。在整个事件中观察到的所有死亡或濒死的大口黑鲈都被记录并移除。在本研究中，我们估计了死亡率，并在疫情爆发后检查了鱼的大小分布、健康状况和生物量。使用船载电捕鱼法收集大口黑鲈，以进行标记重捕种群估计和其他种群指标的测定。对鱼样本进行检查，以寻找LMBV、其他传染病和身体异常的证据。用濒死鱼的样本接种细胞培养物后出现了LMBV典型的细胞病变效应，聚合酶链反应（PCR）证实了LMBV的存在。估计剩余的标准规格大口黑鲈总数（N±95%置信区间）为2301±528尾鱼（103尾/公顷）。在LMBV疫情爆发期间，观察到的总死亡数，包括死亡和濒死个体，为176尾大口黑鲈（占初始种群的7%）。估计剩余的总生物量为1592千克标准规格的鲈鱼，每公顷标准规格大口黑鲈的相对生物量为71.5千克。大口黑鲈的大小结构以优质和偏好的（300 - 510毫米）大小类别为主，极少有超大型或更大（>510毫米）的鱼，并且大口黑鲈的相对重量异常多变。这些结果表明，尽管LMBV疫情导致了死亡，但水库中大口黑鲈的数量和生物量仍然非常高。
