Naqvi S M, Newton D J
Department of Biological Sciences, Southern University, Baton Rouge, LA 70813.
J Environ Sci Health B. 1991 Aug;26(4):437-47. doi: 10.1080/03601239109372747.
The major objective of this work was to assess the possible long-term effects of Thiodan insecticide on the growth-rate, fecundity and hatching potential of Louisiana crayfish, Procambarus clarkii. Adult males and females were collected from an Experiment Station, and were exposed to 600 ppb Thiodan. Since the aqueous solubility of endosulfan (active ingredient of Thiodan) is very low, the actual concentration of 2, 10, 15 and 600 ppb Thiodan in tap water was determined by electron-capture gas chromatography. The amount of endosulfan I and II in 2 ppb Thiodan was 0.8 and 0.32 ppb, respectively; 10 ppb = 3.8 and 1.52; 15 ppb = 6.3 and 2.52; and 600 ppb = 284 and 113.6 endosulfan I and II, respectively. Male and female crayfish were exposed to 600 ppb Thiodan for 20 weeks during which mating occurred. The mean number of eggs produced by control crayfish (N = 10) was 288 and by treated crayfish (N = 10) was 225, which did not differ significantly. Hatchlings from unexposed crayfish were used to determine the effects of Thiodan on weight, length and molting frequency. Sixty hatchlings were exposed to 2, 10 and 15 ppb Thiodan for a period of 9, 23 and 27 weeks during which they achieved a mean weight (gain) of 0.64, 0.19 and 0.17 g, respectively. Control hatchling gained 0.82, 0.30 and 0.19 g during the same period. These differences were also insignificant statistically. The length (gain) by these hatchlings (control and treated) over the same time period did not differ significantly. There was a slight increase (insignificant) in the molting frequencies of treated hatchlings. Comparative data on the chronic effects of Thiodan for crayfish are not available. Based on the reported LC50 values for grass shrimp, mysid shrimp and Korean shrimp, we conclude that Louisiana crayfish, P. clarkii is more tolerant to this insecticide than the other decapod crustaceans.
这项工作的主要目的是评估硫丹杀虫剂对路易斯安那螯虾（克氏原螯虾）的生长速率、繁殖力和孵化潜力可能产生的长期影响。成年雄性和雌性螯虾从一个实验站采集，并暴露于600 ppb的硫丹环境中。由于硫丹（硫丹的活性成分）的水溶性非常低，通过电子捕获气相色谱法测定自来水中2、10、15和600 ppb硫丹的实际浓度。2 ppb硫丹中硫丹I和II的含量分别为0.8和0.32 ppb；10 ppb = 3.8和1.52；15 ppb = 6.3和2.52；600 ppb = 284和113.6硫丹I和II。雄性和雌性螯虾在交配期间暴露于600 ppb硫丹环境中20周。对照螯虾（N = 10）产的卵平均数量为288个，处理过的螯虾（N = 10）产的卵平均数量为225个，二者无显著差异。未暴露的螯虾孵化出的幼体用于确定硫丹对体重、体长和蜕皮频率的影响。60只幼体分别暴露于2、10和15 ppb硫丹环境中9、23和27周，在此期间它们的平均体重（增加量）分别为0.64、0.19和0.17 g。对照幼体在同一时期体重增加了0.82、0.30和0.19 g。这些差异在统计学上也不显著。这些幼体（对照和处理组）在同一时间段内的体长（增加量）没有显著差异。处理过的幼体的蜕皮频率略有增加（不显著）。目前尚无关于硫丹对螯虾慢性影响的比较数据。根据报道过的草虾、糠虾和韩国虾的半数致死浓度值，我们得出结论，路易斯安那螯虾（克氏原螯虾）比其他十足目甲壳类动物对这种杀虫剂更具耐受性。
