Nano Gobies

Mini Dart Goby, Aioliops megastigma
cifically, these fishes don’t spend their lives resting on
the substrate, but swim in the open water above and at
some distance from large stony corals, into which they
flee when danger is imminent. They feed on the finest
of pelagic zooplankton and are so efficient at obtaining
their food that they can be difficult to keep in the
aquarium—because its constant movement expends so
much energy, such a tiny goby must eat continuously in
order to avoid starvation. The requisite heavy feeding can
cause problems in the limited volume of water in a nano
reef aquarium.
In the aquarium
Aquarium size: 4 gallons (15 L) and up.
Food: Very fine frozen food and plankton (for example
lobster eggs, tiger copepods, CYCLOP-EEZE).
Degree of difficulty: High.
Hints for maintenance: Should be kept in small groups;
feed small portions as often as possible, at least three
times daily.
GENUS BRYANINOPS
Without exception, the 10 species of the genus Bryaninops
are true dwarfs measuring 0.5–1.5 inches (1.5–4
cm), and their ecology is typical of all coral gobies. In
hardly any other genus is the commensal relationship
with cnidarians as hosts so close. These tiny gobies either
inhabit gorgonians (in the case of Bryaninops amplus or
B. yongei, for example), or (for example, Bryaninops natans)
live in association with large specimens of smallpolyp
stony corals, usually those of the genus Acropora,
above which they hover to capture plankton. When danger
threatens they disappear lightning-fast among the
coral branches.
While the members of the genus associated
with stony corals are active swimmers,
those that inhabit gorgonians are very passive
and simply sit quietly on a branch, employing
a finely honed camouflage strategy:
all Bryaninops are more or less transparent,
and an elongate goby of this type, nestling
tightly against the branch of a sea whip,
merges almost completely with the substrate
to become invisible. The free-swimming species
are also well camouflaged by virtue of
their translucent, often very light-colored
bodies: these tiny little streaks, swimming in
large groups above the corals and dancing in
the sunlight of the shallows, are probably not
recognized as worthy prey by many predators
but rather as something totally different—
Whip Coral Goby, Bryaninops yongei, true
to its name, is usually found on gorgonians.
This specimen on a Junceella sp. is exhibiting
normal coloration in the first photo (top). In
the second (bottom), it is camouflaged using
mimetic adaptation to the host coral; polyp-like
structures resembling the contours of the coral
have been created inside the body using color
pigments. This change took place in the space of
a few seconds and could be reproduced.
TOP: P. SCHMEIDEL; BOTTOM: D. KNOP
60 CORAL