Well fuck, I guess this probably explains it. Yao & Li, 2018:
Mandarin fish have unusual feeding habits. The fish only eat live fish and shrimps, and do not consume dead prey or artificial diets during all lifecycle stages (Chiang 1959; Li et al. 2014a; Yao and Liang 2015). In nature it is completely carnivorous, and has been found to capture live fry of other fish species from the first feeding stages (Chiang 1959).
Also makes substitutes for fish fry not very promising; they’d probably also have to be other animals. But maybe we could find some that matter much less per kg.
Otherwise, we’d probably just want to reduce mandarin fish production, which could be hard to target specifically, especially being in China.
According to data from the China Fishery Statistical Yearbook, the fry number of freshwater fish increased from 59.51 billion in 1981 to 1.252 trillion in 2019, while the fry number of marine fish increased from 167 million in 1996 to 11.44 billion in 2019 [6,7].
Well fuck, I guess this probably explains it. Yao & Li, 2018:
Also makes substitutes for fish fry not very promising; they’d probably also have to be other animals. But maybe we could find some that matter much less per kg.
Otherwise, we’d probably just want to reduce mandarin fish production, which could be hard to target specifically, especially being in China.
Some different fry numbers in Hu et al., 2021: