Utilization of a Gender-Based Sorting Machine for Crustacean Selection in Bioconcentration Studies with the Freshwater Amphipod Hyalella azteca

摘要

Bioconcentration factors (BCFs) are determined by fish flow‐through tests performed according to Organisation forEconomic Co‐operation and Development test guideline 305. These are time‐consuming and expensive and use a largenumber of animals. An alternative test design using the freshwater amphipod Hyalella azteca for bioconcentration studieshas been recently developed and demonstrated a high potential. For bioconcentration studies using H. azteca, maleamphipods are preferred compared with female organisms. Manual sexing of male adult amphipods is, however, timeconsumingand requires care and skill. A new fully automatic sorting and dispensing machine for H. azteca based on imageanalysis has recently been developed by the company Life Science Methods. Nevertheless, an anesthesia step is necessaryprior to the automatic selection. In the present study, we show that a single‐pulse of 90 min of tricaine at the concentration of1 g/L can be used and is recommended to select H. azteca males manually or automatically using the sorting machine. In thesecond part, we demonstrate that the machine has the ability to select, sort, and disperse the males of a culture batch ofH. azteca as efficiently as manual procedures. In the last part of the study, BCFs of two organic substances were evaluatedusing the H. azteca bioconcentration test (HYBIT) protocol, with an anesthetizing step and robotic selection compared withmanual selection without an anesthetizing step. The different BCF values obtained were in accordance with those indicatedin the literature and showed that an anesthetizing step had no effect on the BCF values.