we have something too similar to be a coincidence, a Jerguilla. Easy to shoot too.
Guia de Peces, Jerguilla.
It is (was) also looked down on but the flesh is white and firm and IMHO tasty. I don't like too oily a fish. It eats weed almost exclusively and its intestine is extremely long to aid the digestion: hence on gutting it smells of old cabbage! (actually, more of farts, not to be too subtle). If you gut them quickly and by the ocean, rinsing abundantly, the farty smell is no problem.
The shame is, that as the "better" fish are over exploited, these "second class" fish start to look more appealing. SAD.