Nano Gobies

mens from this genus appear to have been determined,
the odds must be considerable that the ages of older animals—maybe
vastly older animals—await discovery.
FIRE IN THE HOLE
There is really no way to age the calcareous skeletons
of hydrocorals, and that presents particular problems in
determining their ages. They form small colonies, but it
certainly appears that some of them, particularly some
of the colder water stylasterines, may live quite long.
The few ecological studies on them indicate that once
the colony gets about a year old, it may last decades, but
there are no definitive data on how long they last. No
ecological studies have been undertaken that give any
idea of the parameters of individual growth rates, mortality
rates, or causes of death.
On the other hand, the milleporines, or fire corals,
of tropical reefs that form the other end of the coral age
scale from the deep-water “oldies” are reasonably well
studied. Fire corals are rapidly growing, highly adventitious,
and temporally transitory animals. In other words,
they are the coral equivalent of weeds and possess an
ecological growth strategy that can be summed up with
the phrase: “Live Fast, Die Young, and Leave a Butt-Ugly
Corpse.” Varying from reef to reef and species to species,
a reasonable average for the maximum age of most fire
coral colonies is about a decade. Maximal growth rates
appear to be around an inch (2.5 cm) a year.
SO…HOW OLD CAN A CORAL GET?
Obviously, it depends on the coral—both the coral type
and the specific coral species within any given type.
What it doesn’t seem to depend upon is geographical
region; old corals of one sort or another may be found
anywhere and everywhere. In Table 1, I have given a few
representative data about the extreme life spans for various
types of coral living in various habitats. Perhaps a
general rule of coral longevity may be developed, but if
so that rule—and the work to support it—are still largely
in the future. In the interim, it is probably best to deal
with those few coral species whose longevities have been
determined on a case-by-case basis.
Given the paucity of examples, it is prudent to avoid
drawing too many conclusions about coral ages, but
gingerly stepping out on the limb of the fragile branching
Acropora, I will make some. First, it appears that on
average, deep-water corals probably live longer than do
shallow-water ones. Second, it appears that long-lived
corals are slow-growing corals. Finally, there is the wild
card of asexual reproduction. To date, there has been
no study that gives us a handle on the longevity of the
genomes of highly fragmenting corals, such as various
84 CORAL