Freshwater in Malaysia is patin, keli, temoleh, ikan hantu and few others. Chinese names are patin, tong sat, soon hock, Tak you lei. Other species edible is wan yue and wang bu liao . Empurau.

Most is farmed except temoleh and wang bu liao which is still natural for now. Mercury comment is higher cause most farms do not wash their sangkar.

Marine edible species too many to name. Snapper and grouper the most common . That alone also variety of species and mostly farmed.

Jenahak, kerapu, bawal, siakap, ikan merah, semilang, etc etc are some of the more common ones. Red snapper, golden snapper, mutton snapper, mangrove Jack, tiger grouper, Goliath grouper, hybrid grouper, barramundi.
Chinese is the pan family , Lou Fu pan , sekpan , loong Dan for grouper and Zhou family is hung Zhou, Kam Zhou , pak Zhou for snapper family. Siakap is common species.

Most Marine fish are farmed as well.
Hybrid grouper is a cross between tiger and Goliath and hence is what you are eating in most of the restaurants. But they still coin it as sek pan, even though it's already crossed hybrid between 2 species.
Ok?

Mercury content depends on which Waters and which farm and their water structure.