Yellow clown goby
Encyclopedia
The yellow clown goby, Gobiodon okinawae, also known as the Okinawa goby or yellow coral goby, is a member of the goby
family native to the western Pacific
from southern Japan
to the southern reaches of the Great Barrier Reef
. As the name implies, they are bright yellow in color, save for a whitish patch on each cheek. Equally bright as their coloration is their personality; they are valued additions to reef aquaria, with a reputation for being friendly and entertaining.
spines, ten soft dorsal rays, one anal
spine, and nine anal soft rays. At maturity they can reach a length of 3.5 cm.
Another species, Gobiodon citrinus
, the citrus goby, has a similar appearance to Gobiodon okinawae. G. okinawae, however, lacks the requisite blue and white facial markings of G. citrinus.
These fish are not generally aggressive, though they can actively protect their territory against their own kind. Their primary defense against predators is a poison
ous, bitter mucus
on their skin that makes them unpalatable.
The yellow clown goby inhabits the coral reefs of sheltered lagoons. Unlike most gobies, which are burrowers, Gobiodon sp. roost in the outer branches of Acropora
(staghorn
) coral
s, in groups of five to fifteen individuals.
s, and the yellow clown goby is further subcategorized as a planktivore. Given their small size, their diet consists mainly of mesoplankton
.
They are opportunistic feeders, not hunters. The typical eating behavior is to wait for food to come into range, at which point they dart out to grab it and then immediately return to their roost.
. It is especially suited to nano reef tanks because of its small size, and the ability of the aquarist to closely monitor its health.
Because of territorial
issues with their own kind in the small confines of a tank, they are best kept singly or as a breeding pair.
Given host corals in which to "roost", these fish are a colorful and entertaining addition to reef tanks. Many gobies become accustomed to their keepers, recognize their presence, and seem to beg for food. Additionally, when perching in a favorite location, they seem to do a "fish dance" where they wiggle back and forth in an undulating motion while waving their fins.
Many of these fish arrive at retailers in emaciated condition and are slow or finicky eaters. They often starve in the presence of more voracious feeders, such as wrasse
s. Care must be taken to ensure they start eating within one or two days of acquisition.
They are carnivorous and initially do not readily take flake or pellet foods, instead preferring live or frozen. Suggested foods include Cyclop-eeze, live brine shrimp
fortified with phytoplankton
to boost nutritional value, Sweetwaters Zooplankton, frozen or live mysis
shrimp, and finely chopped silversides (a commonly available small fish sold fresh or frozen). This animal, like many other marine species, requires a varied diet to survive in long term captivity. Regular feeding of at least four kinds of foods is recommended.
. The species is highly resilient, with localized populations able to double within fifteen months.
to form a breeding pair. In the case of two females forming a pair, the larger of the two becomes male, and in the case of two males, the smaller changes sex to become female. The only time a male is smaller than a female is when a small male is placed in the same coral as a large female.
The eggs
are laid in circular bands around coral branches in masses of up to a thousand. The male will immediately fertilize
them and guard until hatching, about five days later. At about day 33, the fry
undergo metamorphosis
and begin to settle. Coloration can be seen at about day 40.
Goby
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. Most are relatively small, typically less than 10 cm in length...
family native to the western Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
from southern Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
to the southern reaches of the Great Barrier Reef
Great Barrier Reef
The Great Barrier Reef is the world'slargest reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,600 kilometres over an area of approximately...
. As the name implies, they are bright yellow in color, save for a whitish patch on each cheek. Equally bright as their coloration is their personality; they are valued additions to reef aquaria, with a reputation for being friendly and entertaining.
Description
G. okinawae have a generally fusiform shape with seven dorsalDorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
spines, ten soft dorsal rays, one anal
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
spine, and nine anal soft rays. At maturity they can reach a length of 3.5 cm.
Another species, Gobiodon citrinus
Gobiodon citrinus
Gobiodon citrinus is a Goby from the Indo-West Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 6.6 cm in length....
, the citrus goby, has a similar appearance to Gobiodon okinawae. G. okinawae, however, lacks the requisite blue and white facial markings of G. citrinus.
These fish are not generally aggressive, though they can actively protect their territory against their own kind. Their primary defense against predators is a poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ous, bitter mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
on their skin that makes them unpalatable.
Habitat
Acropora
Acropora is a genus of scleractinian coral in the Phylum Cnidaria. Some of its species are known as table coral, elkhorn coral and staghorn coral. There are currently 149 described species...
(staghorn
Staghorn coral
The Staghorn coral is a branching coral with cylindrical branches ranging from a few centimetres to over two metres in length and height. It occurs in back reef and fore reef environments from 0 to 30 m depth. The upper limit is defined by wave forces, and the lower limit is controlled by...
) coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s, in groups of five to fifteen individuals.
Diet
Most gobies are carnivoreCarnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
s, and the yellow clown goby is further subcategorized as a planktivore. Given their small size, their diet consists mainly of mesoplankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
.
They are opportunistic feeders, not hunters. The typical eating behavior is to wait for food to come into range, at which point they dart out to grab it and then immediately return to their roost.
In the aquarium
The yellow clown goby is popular with aquarists and is generally considered to be reef safeReef safe
Reef safe is a distinction used in the saltwater aquarium hobby to indicate that a fish or invertebrate is safe to add to a reef aquarium. There is no fish that is completely reef safe. Every fish that is commonly listed as reef safe are species that usually do not readily consume small fish or...
. It is especially suited to nano reef tanks because of its small size, and the ability of the aquarist to closely monitor its health.
Because of territorial
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
issues with their own kind in the small confines of a tank, they are best kept singly or as a breeding pair.
Given host corals in which to "roost", these fish are a colorful and entertaining addition to reef tanks. Many gobies become accustomed to their keepers, recognize their presence, and seem to beg for food. Additionally, when perching in a favorite location, they seem to do a "fish dance" where they wiggle back and forth in an undulating motion while waving their fins.
Many of these fish arrive at retailers in emaciated condition and are slow or finicky eaters. They often starve in the presence of more voracious feeders, such as wrasse
Wrasse
The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 82 genera, which are divided into nine subgroups or tribes....
s. Care must be taken to ensure they start eating within one or two days of acquisition.
They are carnivorous and initially do not readily take flake or pellet foods, instead preferring live or frozen. Suggested foods include Cyclop-eeze, live brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
fortified with phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
to boost nutritional value, Sweetwaters Zooplankton, frozen or live mysis
Mysidae
Mysidae is a family of crustaceans in the order Mysida or mysid shrimps. Six sub-families are recognised:* Boreomysinae Holt & W. M. Tattersall, 1905a* Siriellinae Norman, 1892* Rhopalophthalminae Hansen, 1910* Gastrosaccinae Norman, 1892...
shrimp, and finely chopped silversides (a commonly available small fish sold fresh or frozen). This animal, like many other marine species, requires a varied diet to survive in long term captivity. Regular feeding of at least four kinds of foods is recommended.
Conservation status
The yellow clown goby is not found on the IUCN Red ListIUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. The species is highly resilient, with localized populations able to double within fifteen months.
Reproduction
Gobiodon sp. start life as females, and are bi-directional protogynous hermaphrodites, meaning that when paired up, if necessary, one changes sexSex change
Sex change is a term often used for gender reassignment therapy, that is, all medical procedures transgendered people can have, or specifically to sexual reassignment surgery, which usually refers to genitalia surgery only...
to form a breeding pair. In the case of two females forming a pair, the larger of the two becomes male, and in the case of two males, the smaller changes sex to become female. The only time a male is smaller than a female is when a small male is placed in the same coral as a large female.
The eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
are laid in circular bands around coral branches in masses of up to a thousand. The male will immediately fertilize
Fertilisation
Fertilisation is the fusion of gametes to produce a new organism. In animals, the process involves the fusion of an ovum with a sperm, which eventually leads to the development of an embryo...
them and guard until hatching, about five days later. At about day 33, the fry
Fry
-Food and cooking:* Frying, the act of cooking food in oil or fat** Pan frying, frying food in a flat pan** Stir frying, frying food in a wok and stirring it while it cooks* Full breakfast, a traditional cooked meal, also called a fry-up or Ulster fry...
undergo metamorphosis
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
and begin to settle. Coloration can be seen at about day 40.