The yellow clown goby, ''Gobiodon okinawae'', also known as the Okinawa goby or yellow coral goby, is a member of the

goby Goby is a common name for many species of small to medium sized ray-finned fish, normally with large heads and tapered bodies, which are found in marine, brackish and freshwater environments. Traditionally most of the species called gobies have b ...

family native to the western

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

from southern Japan to the southern reaches of the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

. As the name implies, they are bright yellow in color, save for a whitish patch on each cheek.

Description

''G. okinawae'' have a generally fusiform shape with seven

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

spines, ten soft dorsal

rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra ...

, one

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving s ...

spine, and nine anal soft rays. At maturity they can reach a length of 3.5 cm.Gobiodon okinawae
Fishbase.org, retrieved 4 November 2007 Another species, ''

Gobiodon citrinus ''Gobiodon citrinus'', the poison goby, is a species of goby native to the Indian Ocean from the Red Sea and the coast of Africa to the western Pacific Ocean to Japan, Samoa and the Great Barrier Reef. They are reef dwellers being found at dept ...

'', 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 poisonous, bitter

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...

on their skin that makes them unpalatable."Fish Tales - Let's clown around with more Gobies - the Gobiodon species"
Henry C. Shultz III, ''Reefkeeping Magazine'', October 2002, retrieved 4 November 2007

Habitat

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 Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and ...

s, in groups of five to fifteen individuals.

Diet

Most gobies are

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other s ...

s, and the yellow clown goby is further subcategorized as a

planktivore A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and i ...

. Given their small size, their diet consists mainly of mesoplankton. They are

opportunistic feeder Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγε ...

s, 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

aquarist An aquarist is a person who manages aquariums, either professionally or as a hobby. They typically care for aquatic animals, including fish and marine invertebrates. Some may care for aquatic mammals. Aquarists often work at public aquariums. They ...

s and is generally considered to be reef safe. It is especially suited to nano reef tanks because of its small size, and the ability of the aquarist to closely monitor its health. Equally bright as their coloration is their personality; they are valued additions to reef aquaria, with a reputation for being friendly and entertaining. Because of

territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

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 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 81 genera, which are divided into 9 subgroups or tribes. They are typically small, most of them le ...

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 live

brine shrimp ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia L ...

fortified with phytoplankton to boost nutritional value, Zooplankton, frozen or live

mysis ''Mysis'' is a genus of mysid crustaceans in the family Mysidae, distributed mainly in the coastal zone of the Arctic and high boreal seas. Several species also inhabit northern freshwater lakes and the brackish Caspian Sea. Fifteen species are ...

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 List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

. 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 Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, ...

hermaphrodites In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have sep ...

, meaning that when paired up, if they are both of the same sex, one changes sex 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 Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

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.

References

External links

* {{Taxonbar, from=Q1499287 Gobiodon Fish described in 1972