Gobies |
![Microgobius gulosus](./modules/Fish-MM/images/200px-Microgobius_gulosus1.jpg)
Microgobius gulosus
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Scientific classification |
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Subfamilies |
Amblyopinae
Gobiinae
Gobionellinae
Oxudercinae
Sicydiinae |
The gobies form the
family Gobiidae, which is one of the largest
families of
fish, with more than 2,000
species in more than 200 genera.[1] Most are relatively
small, typically less than 10 cm (4 in) in length. Gobies
include some of the smallest vertebrates in the world, like
species of the genera Trimmaton and Pandaka, which are under
1 cm (3/8 in) long when fully grown. There are some large
gobies, such as some species of the genera Gobioides or
Periophthalmodon, that can reach over 30 cm (1 ft) in
length, but that is exceptional. Although few are important
as food for humans, they are of great significance as prey
species for commercially important fish like cod, haddock,
sea bass, and
flatfish. Several gobies are also of interest as
aquarium fish, such as the bumblebee gobies of the genus
Brachygobius.
The most distinctive aspect of goby morphology are the
fused
pelvic fins that form a disc-shaped sucker. This sucker is
functionally analogous to the dorsal fin sucker possessed by
the remoras or the pelvic fin sucker of the lumpsuckers, but
is anatomically distinct: these similarities are the product
of convergent evolution. Gobies can often be seen using the
sucker to adhere to rocks and corals, and in
aquaria they will happily stick to glass walls of the
tank as well.
Gobies are primarily fish of shallow marine habitats
including
tide pools, coral reefs, and seagrass meadows; they are also
very numerous in brackish water and estuarine habitats
including the lower reaches of rivers, mangrove swamps, and
salt marshes. A small number of gobies (unknown exactly, but
in the low hundreds) are also fully adapted to freshwater
environments. These include the Asian river gobies (Rhinogobius
spp.), the Australian desert goby (Chlamydogobius eremius),
and the European freshwater goby Padogobius bonelli.
Mudskippers
Mudskippers are highly specialised members of the family,
usually ascribed to the subfamily
Oxudercinae. They are able to survive for extended
periods on land through a combination of behavioural and
physiological adaptations, including pectoral fins that act
as simple legs; the ability to breathe through their skins
(like frogs); and the digging of damp burrows to avoid
drying out. Mudskippers live in tidal areas, particular on
mudflats and in mangrove forests, and are only found in
tropical and subtropical regions.
Symbiosis
Some marine gobies live in symbiosis with a
shrimp.
Gobies sometimes form symbiotic relationships with other
species.[2] Some goby species live in symbiosis with
burrowing shrimps. The shrimp maintains a burrow in the sand in
which both the shrimp and the goby fish live. The shrimp has
poor eyesight compared to the goby, but if it sees or feels
the goby suddenly swim into the burrow, it will follow. The
goby and shrimp keep in contact with each other, the shrimp
using its antennae, and the goby flicking the shrimp with
its tail when alarmed. These gobies are thus sometimes known
as watchman gobies. Each party gains from this
relationship: the shrimp gets a warning of approaching
danger, and the goby gets a safe home and a place to lay its
eggs.
Another example of symbiosis is demonstrated by the neon
gobies (Gobiosoma spp.). These gobies are known as "cleaner
gobies", and remove parasites from the skin, fins, mouth,
and gills of a wide variety of large fish. The most
remarkable aspect of this symbiosis is that many of the fish
that visit the cleaner gobies' cleaning station would
otherwise treat such small fish as food (for example
groupers and snappers). Again, this is a relationship where both
parties gain: the gobies get a continual supply of food as
big fish visit their cleaning stations, and the big fish
leave the cleaning station healthier than they were when
they arrived.
In aquaria
Two freshwater gobies,
Rhinogobius duospilus, a hardy
subtropical species that does well in aquaria.
Several species of goby are kept in aquaria.[3]
The bumblebee gobies, genus Brachygobius are perhaps the
most widely traded examples, being small, colourful, and
easy to care for. They need tropical, hard and alkaline
freshwater or slightly brackish conditions to do well.
Gobies are generally peaceful towards their tankmates though
territorial among themselves. Since most are small and few
are predatory towards other fishes, they usually make good
community fishes. Typically, the main problem with gobies is
feeding them: with a few exceptions, the small species kept
in aquaria prefer live or frozen foods rather than flake,
and they are not very good at competing with active species
such as cichlids. It is often recommended that gobies be
kept on their own or with peaceful surface dwelling species
such as halfbeaks and guppies.
See also
-
Sleeper gobies are a closely-related family
(Eleotridae) that lack the fused pelvic fin sucker
typical of most gobies but are otherwise very similar in
size, shape, and ecology.
-
Blennies are a group of shallow water marine fish
often confused with gobies.
-
Dragonets are superficially similar to gobies and
sometimes confused with them.
References
- ^
"Gobiidae".
FishBase. Ed. Ranier Froese and Daniel Pauly.
January 2006 version. N.p.: FishBase, 2006.
- ^
G. S.
Helfman, B. B. Colette & D. E. Facey (1997). “Chapter
21: Fishes as social animals”, The Diversity of
Fishes. Blackwell.
ISBN 0-86542-256-7.
- ^
Frank
Schäfer (2005). Brackish-Water Fishes. Aqualog.
ISBN 3-936027-82-X (English), ISBN 3-936027-81-1
(German).
External links