Almost all Reef fish have the same generalized life
history: they disperse while young, and then as
adults, they stay put.
There are three different spawning types:
(a) Pelagic eggs (released into the
water column to drift with the currents);
(b) Demersal
eggs (attached to the bottom and guarded by the male);
and
(c) Brooded eggs (kept in the mouth or pouch of
the male until hatched).
Once the eggs hatch in the
vast majority of species (i.e., greater than 95%), the
larva will be planktonic, dispersing with the surface
ocean currents. Very little is known about the larval
or juvenile stages of coral reef fishes. However, we
do know that this stage of their life cycle has
important ecological consequences. Because the larval
fish are traveling with the large-scale ocean currents
that can circle halfway around the world, reef fish
have the potential to disperse over vast areas of
ocean. But since the mortality is very high during
the pelagic stage of their life, only a small percentage of the young fish will survive long enough to settle and establish themselves in a reef. Another consequence of
the pelagic larval stage is that it is possible to
have reserves that can produce individuals to fill in
areas that have been depleted. (For more information
on how Fish Replenishment Areas has effected
management of coral reef fish -See FRAs link) Since
adults remain their whole lives in a small area, this
final stage is the most studied and best understood.
