Standard model species are commonly used in toxicity tests due to their biological and technical advantages but studying native species increases the specificity and relevance of results generated for the potential risk assessment to an ecosystem. Accounting for intraspecies variability and other factors, such as chemical and physical characterization of test medium, is necessary to develop a reproducible bioassay for toxicity testing with native species. In this study, larval stage I American lobster (Homarus americanus), a commercially important and native species of Atlantic Canada, was used as the test species. Toxicity tests were first conducted by exposing lobster larvae to a reference toxicant of copper sulphate (CuSO₄) and then to physically and chemically (using Corexit 9500A) dispersed oil (WAF and CEWAF, respectively). The effect on larval survival was estimated by calculating the 24-h median effect concentration (24-h EC50), and there was no difference between WAF or CEWAF exposure when the results are reported on a total petroleum hydrocarbon (TPH) basis. The 24-h EC50s ranged from 2.54 to 9.73 mg TPH/L when all trials (n = 19) are considered together. The HC5 (hazardous concentration for 5 per cent of the population) value was 2.52 mg TPH/L and similar to the EC50 value when all trials were pooled. To evaluate the reproducibility of the lobster toxicity tests, inter-trial variability was determined, and the resultant coefficients of variation (%CV) were compared to those reported for two standard test species, mysid shrimp (Americamysis bahia) and inland silverside (Menidia beryillina). This comparison showed that the %CV for the lobster toxicity tests were lower than those for the standard species tests indicating that the described larval lobster toxicity bioassay produces reliable and repeatable results.

标准模型物种因其生物学和技术优势而常用于毒性测试，但研究本地物种可提高对生态系统进行潜在风险评估所产生结果的特异性和相关性。考虑到种内变异性和其他因素，例如测试培养基的化学和物理特性，对于开发用于本地物种毒性测试的可重复生物测定是必要的。在这项研究中，幼虫 I 期美洲龙虾 ( Homarus americanus ) 是加拿大大西洋地区具有重要商业价值的本地物种，被用作试验物种。首先通过将龙虾幼虫暴露于硫酸铜（CuSO ₄)，然后以物理和化学方式（使用 Corexit 9500A）分散油（分别为 WAF 和 CEWAF）。通过计算 24 小时中位效应浓度 (24 小时 EC50) 估计对幼虫存活的影响，当结果以总石油烃 (TPH) 为基础报告时，WAF 或 CEWAF 暴露之间没有差异。当所有试验（n = 19) 一起考虑。HC5（5% 人口的危险浓度）值为 2.52 mg TPH/L，与汇总所有试验时的 EC50 值相似。为了评估龙虾毒性试验的可重复性，确定了试验间的变异性，并将所得变异系数 (%CV) 与两种标准试验物种报告的变异系数 (%CV) 进行比较，即糠虾 ( Americamysis bahia ) 和内陆银虾 ( Menidia beryillina）。该比较表明龙虾毒性测试的 %CV 低于标准物种测试的百分比，表明所描述的幼虫龙虾毒性生物测定产生了可靠且可重复的结果。