Two
spot gobies or Signigobius
biocellatus are members of the
family Gobiidae.
This is a rather large family consisting of over 2,000 individual
species in
more than 200 genera. Two spots are indigenous to the Indo-Pacific.
They range
form the Philippines
south to Australia.
This
species has the elongated cylindrical body one would
expect to find in a goby.
One
of the
more interesting aspects of gobies is their wide variety of coloration
and body
patterning. Two spots are yet another example of these variations.
Compared to
the exotic coloration typical of many gobies, this species is rather
bland in
appearance. It has a light tan body splattered with brown and pale
orange
markings of various shapes and sizes. This
coloration makes it blend in almost seamlessly against the backdrop of
the
ocean floor or while perched atop a rock formation.
The most
distinguishing
characteristic of this species is its two dorsal fins.
These fins stand
erect
on the fishes back. They are taller than the fish’s actual
body. Each of theses
fins has a large false eyespots meant to confuse predators. When this
fish is
viewed from the side, it looks very much as if you are staring into the
face of
a fish two to three times its size. It is these two eyespots (ocelli)
for which
the fish is named. These fish are also sold by the aquarium industry
under the
names; twinsspot goby, signal goby, and crabeye goby.
Two
spots are bottom dwellers. As with many bottom dwellers,
this is primarily a scavenger fish. These fish sift through sand in
search of
food. They are also burrowers. Two spots use their mouths to carry away
sand
and rubble in the construction of their burrows. An aquarium with an
adequate
supple of live rock and living sand as a substrate will emulate their
natural
habitat, provide them with a secondary food source, and prevent them
from
accidentally damaging themselves.
This
is a small, exceptionally mild mannered fish. They only
grow to an average length of 2.5 inches. They make wonderful additions
to both multi-species
and marine reef aquariums. These gobies should not be housed with
larger or
even moderately aggressive fish. Unlike most bottom dwellers, two spots
are
tolerant of other bottom dwelling fish. They may however exhibit
territorial
behavior toward conspecifics. A mated pair may be successfully housed
together.
Depending on the population of your aquarium, this species can be
housed in as
little as a 10 gallon tank. This is a short-lived species. Their
average life
span is only about two years. Two spots have a moderate care level.
They can be
raised by intermediate saltwater aquarists.
Two
spots are carnivorous. They should take readily to flake
food or pellets formulated for meat eaters. To keep them healthy and
vigorous,
their diets should be supplemented with mysid or brine shrimp or any
other
supplement commonly fed to marine carnivores. They should be fed 1-2
times daily.
Breeding
Two Spot Gobies
In
nature, this species is most commonly observed in pairs.
They are monogamous by nature. Male-female couples cohabitate in the
same
burrow. A sexually mature fish will commonly starve itself to death if
becomes
separated from its life mate.
This species is known to
breed
in captivity. Their spawning
habits are indeed quite unique. The female will first enter the burrow
to
deposit her eggs. She will then seal the male in the burrow for the
eggs to be
fertilized. The male will remain in the burrow for 2-3 days. During
this time
the female will periodically unseal the burrow and release the male.
The male
may eat or the couple may perform routine maintenance on the burrow.
Once the
objective has been achieved, the female will reseal the male in the
burrow.
Eventually the male will permanently exit the burrow. The couple will
then
construct another burrow or reopen a previously abandoned one. When the
borrow
that acted as a nursery is unsealed again, a single juvenile will
emerge.
