The chameleon goby (''Tridentiger trigonocephalus'') is a species of ray-finned fish native to marine and brackish waters along the coasts of eastern Asia. It has also spread to other parts of the world where it is found in waters with varying degrees of salinity.

Description

The chameleon goby can reach total length. It is pale greyish-brown with a white-speckled head and two longitudinal black bands extending along the flank from the head to the caudal peduncle. The two dorsal fins may be speckled with white and have a brown longitudinal stripe, and the anal fin an orange or grey band across the centre. Under certain circumstances, this fish can darken in colour so that the black bands are nearly invisible. It is very similar in appearance to the Shimofuri goby (''Tridentiger bifasciatus''), but it has no white spots on the underside of its head and has a white margin to the second dorsal fin and the anal fins. ''T. bifasciatus'' has white spots on both the upper and lower part of the head and an orange-red margin to the second dorsal fin and the anal fins, but lacks the distinctive stripes that ''T. trigonocephalus'' has on these fins. ''T. bifasciatus'' prefers waters with a salinity of less than 22 parts per thousand, while ''T. trigonocephalus'' prefers higher salinities.

Distribution and habitat

The chameleon goby is native to the eastern coast of Asia where its range includes Japan, Korea, China and Siberia. There have been reports that it has been found in the Black Sea, and recently in the eastern Mediterranean Sea from Ashdod harbour, Israel.Atlas of Exotic Fishes in the Mediterranean Sea (''Tridentiger trigonocephalus''). 2nd Edition. 2021. 366p. CIESM Publishers, Paris, Monaco.https://ciesm.org/atlas/fishes_2nd_edition/Tridentiger_trigonocephalus.pdf It is a

demersal fish Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occ ...

, living and feeding near the seabed, both in bays and rocky coasts, in brackish water and freshwater lakes. It typically hides in crevices, under stones, in burrows or among seagrasses.

Biology

The chameleon goby is mainly nocturnal and feeds mostly on invertebrates such as

polychaete worms Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are m ...

which it extracts from the sediment. It also consumes crustaceans including

skeleton shrimps Caprellidae is a family of amphipods commonly known as skeleton shrimps. Their common name denotes the threadlike slender body which allows them to virtually disappear among the fine filaments of seaweed, hydroids and bryozoans. They are sometim ...

and crab larvae. Breeding takes place at intervals throughout the spring and summer. The male prepares a nest in a crevice, a mollusc shell or even a discarded bottle or can. The eggs are guarded by the male and hatch after about ten days. The juveniles become mature within a year and their life expectancy is up to three years.

Invasiveness

The chameleon goby was first detected in Los Angeles harbor in 1960 and was later found at other locations in California including Redwood City docks, the tidal lagoon of Lake Merritt in

Oakland Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the Bay A ...

and

San Diego Bay San Diego Bay is a natural harbor and deepwater port located in San Diego County, California near the U.S.–Mexico border. The bay, which is long and wide, is the third largest of the three large, protected natural bays on California's of c ...

. It has also been reported from Australian waters. Possible means of introduction include being transported in a ship's ballast water, as a result of the commercial trade in Pacific oysters, or as eggs among the fouling organisms on the

hull Hull may refer to: Structures * Chassis, of an armored fighting vehicle * Fuselage, of an aircraft * Hull (botany), the outer covering of seeds * Hull (watercraft), the body or frame of a ship * Submarine hull Mathematics * Affine hull, in affi ...

of a vessel. As an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

it is likely to compete with native species.

References

{{Taxonbar, from=Q2557917 chameleon goby Western North American coastal fauna Fish of the Black Sea Fish of the Sea of Azov chameleon goby Invasive species in Ukraine