I think rockfish and perch are related. Some more info on Wikipedia:

The Zeiformes are a small order of marine ray-finned fishes most notable for the dories, a group of common food fish. The order consists of about 33 species in seven families, mostly deep-sea types.

Zeiform bodies are usually thin and deep. Mouths are large, with distensible jaws, and there is no orbitosphenoid. Pelvic fins have 5-10 soft rays and possibly a spine, 5-10 dorsal fin spines and up to 4 anal fin spines. They range in size from the Dwarf Dory (Macrurocyttus acanthopodus), at 43 millimetres (1.7 in) in length, to the Cape Dory (Zeus capensis), which measures up to 90 centimetres (35 in).[1]

thanks @ ShellfishMary; It is me who has just found out I am allergic to this fish. Thanks for the reply.

thnx shellfishmary i wil let my sister now abt this