Cisco Aquaculture Best Practices: Randomized Experiments from Eggs to Juvenile

Abstract

The Cisco Coregonus artedi (also known as Lake Herring), a coldwater salmonid found in the Great Lakes, is of interest to multiple agencies for restoration and conservation purposes due to its important ecological role. Further information on rearing and restocking of Cisco is needed, especially toward understanding the biological culture needs of Cisco eggs, larvae, and fingerlings. To address this gap in the literature and to provide essential fish culture information, we performed three preliminary studies in 2010 with Cisco: fertilization (wet versus dry fertilization), egg survival (pre-water-hardening versus post-water-hardening iodine treatment), and fry development (three different larval feed treatments that were commercially available at that time). The dry fertilization methodology (68%) yielded a significantly better eye-up percentage than wet fertilization (34%). Additionally, our testing revealed higher survival rates when iodophor treatment was used on fertilized eggs after water hardening (54%) in comparison with treatment before water hardening (43%). Although mean survival rates across the three diet treatments were not significantly different, larval Cisco that were fed brine shrimp Artemia replacement diets outperformed those fed the other diets, with the INVE Proton diet ranking highest. These early preliminary studies substantially increased the understanding of optimum culture parameters for Cisco in preparation for the widespread production of this important species, and the results provide propagation recommendations for conservation stocking programs.