Hey I'm interested in growth rates of oceanic fish, particularly the bony fishes. I haven't been able to find websites that have good info for lots of fish. E.g., for groupers and marlins and such. I'm assuming, they grow rapidly during early life then slow down?
What BC said... variability is massive. Mahi Mahi, for example, mature at 4 to 6 months, while White Sturgeon take 25 years to reach maturity at 6 feet.
To your specific question, you're right in assuming groupers grow more rapidly earlier in their life cycle... that said there's tons of variability there as well species to species.
The information on hand is limited with many species, but a great place to start is fishbase.