Nano Gobies

around 1,476 feet (450 m), where the water temperature
is between 46 and 54°F (8–12°C), or roughly the
same as that found in Puget Sound, Washington; the age
of one of these was determined to be 2,742 years. The
specimens were not very large, less than 6.5 feet (2 m)
in height, and the radial growth rates of the branches,
or how fast a branch got thicker, were extremely low at
0.013–0.001 inch (4–35 μm) per year. Savalia individuals
of such ancient age are not restricted to Hawai’ian
waters; a Savalia skeleton that had lived 1,800 years before
it died was recently recovered near the Bahamas.
Large stand of staghorn Acropora.
Because they reproduce by fragmenting,
a particular genome could theoretically
be millions of years old.
THINGS ARE LOOKING BLACK
The Antipatharians, or black corals, are corals that have
wholly proteinaceous skeletons and small polyps with
only six tentacles. Typically found in deeper waters, a few
species are common at diving depths, and occasionally a
specimen is collected for the aquarium hobby. They may
be quite large, particularly the whip-like wire or whip
corals, Cirripathes species, which may reach over 16 feet
(5 m) in length as they extend from deep reef walls, but
most branching black corals look rather like gorgonians
and are found in the same size range, up to 65 feet (a
couple of meters) high. The common name, black coral,
reflects the color of the skeleton, not the color of the living
tissue, which typically is in hues of orange or yellow
for shallower forms.
Some of the deep-water species are stark white, as are
individuals of a number of other deep-water species, particularly
those of the stony coral Lophelia. Because the
skeletons of black corals are proteinaceous, their ages are
typically determined radiometrically, primarily using the
abundance of the radioactive 14 C isotope of carbon incorporated
into them as it was deposited. This isotope decays
into the stable 12 C at a known and highly calibrated rate.
By measuring the proportional abundances of both carbon
isotopes, the age of the sample can be determined.
To measure the ages of these corals, very small samples
of the skeleton are vaporized and the isotope abundances
are determined; then, using some reference data, it is
relatively easy to determine the age of the sample. Examination
of a few specimens of Antipathes dichotoma
from shallow, 164-foot-deep (50-m) Hawai’ian waters
showed ages from 12 to 32 years. These colonies were
also growing quite rapidly, adding as much as 0.04 inch
(1.1 mm) in branch diameter per year. On the other
hand, samples from several individual corals in what are
probably several different species of Leiopathes are the
“All-Coral” winners of the “olde age lottery.” One specimen
each of an indeterminate species and Leiopathes glaberrima
from near Hawai’i were 4,265 and 2,377 years
old, respectively. The radial growth rates of these colonies
were less than 5μm per year. Leiopathes species are ubiquitous
in the deep sea and have been collected from the
Northwest Pacific, near Antarctica, and many areas in
between. Given that the ages of fewer than a dozen speci-
CBPIX/SHUTTERSTOCK
82 CORAL