I haven't found much info so far. Most of this info was translated from a korean sportfishing site. I deleted the fishing tips and saved the descriptive info on the fish's normal environment. This info can be used as a starting point for maintaining this species in an aquarium setting.
Siniperca scherzeri
Family: Percichthyidae (Temperate perches)
Order: Perciformes (perch-likes)
Class: Actinopterygii (ray-finned fishes)
Max. size: 22.0 cm SL (male/unsexed; Ref. 35840)
Environment: benthopelagic; freshwater; brackish
Climate: temperate
Resilience: Medium, minimum population doubling time 1.4 - 4.4 years(Preliminary K or Fecundity.)
Distribution: Gazetteer Asia: China (Ref. 33450), Korea (Ref. 39317) and Viet Nam (Ref. 44416).
The mandarin fish (Siniperca scherzeri), or "sogari" in Korean, exists only in the clear water of shallow fast moving streams and these places are usually in mountain valleys.
They live among rocks, submerged boulders and pebble riverbeds, Eggs are deposited in a gravel bottom. Late May to mid-July is the spawning period in the Jeolla and Gyeongnam Provinces.
It averages 20 to 30 cm in length, with specimens over 50 cm regarded as a rare trophy. It has a lower jaw longer than the upper jaw, much like a bass and also somewhat comparable to a bass in body and fin shape.
The sogari is the top predator of the food chain in the freshwater ecosystem, eating minnows, insects and crustaceans.The mandarin fish is primarily a nocturnal hunter.