Farmers often sort fish by size to reduce competition and make them grow more evenly. SEAFDEC/AQD Scientist Dr. Frolan Aya tested if the method, known as size grading, works for yellow Pacific shortfin eel (Anguilla bicolor pacifica). Eels were initially raised for 60 days, then separated into three groups: small, large, and mixed. After raising them for another 90 days and measuring their growth and survival, they found that the size grading did not make much difference in the overall growth or survival of the eels. The large eels ate more than the small or mixed eels, but they did not use the feed more efficiently.
Dr. Aya, with his co-authors John Carlo Unida and Dr. Luis Maria Garcia, recently published the results of their study, “Effect of size grading on growth of yellow Pacific shortfin eel (Anguilla bicolor pacifica),” in the Journal of Fish Biology. You may request for a copy of their paper here https://repository.seafdec.org.ph/handle/10862/6423.