2.4. Experimental Animal and Feeding Experiment

All animal experiments were conducted in accordance with the guidelines for the use and care of laboratory animals of the Institutional Animal Care and Use Committee of National Chiayi University (NCYU) (approval no. NCYU-110031).

In total, 240 juvenile redclaw crayfish (average weight, 0.56 ± 0.04 g) were purchased from a fish breeding farm in southern Taiwan and were transferred to our laboratory in a 2000 L fiberglass-reinforced plastic barrel. The redclaw crayfish were acclimatized for 2 weeks and fed commercial feed daily (No. 3; Shye Yih Feeding, Kaohsiung City, Taiwan). After starving the redclaw crayfish for 12 h, we randomly distributed them into 12 fiberglass tanks (20 redclaw crayfish per tank). The redclaw crayfish were fed twice daily (8:00 and 15:00) with one of the four experimental diets (FM, BSM-S, BSM-F, or BSM-P) until satiation for 56 days. Three experimental replicates were used. Fecal matter was collected, dried, and stored in a freezer before each feeding session. The amount of feed consumed by the redclaw crayfish in each tank was recorded every week.