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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Chameleon Goby

Synonyms and Other Names: shimahaze, striped tripletooth goby

Taxonomy: available through www.itis.gov

Identification: Eschmeyer et al. (1983). Distinguishing characteristics were also provided by Masuda et al. (1984), Akhito and Sakamoto (1989), and Matern and Fleming (1995). Color photographs appeared in Masuda et al. (1984) and in Akihito and Sakamoto (1989). Tridentiger bifasciatus, formerly considered a synonym, was resurrected by Akihito and Sakamoto (1989). This species can be separated from the morphologically similar T. bifasciatus primarily based on coloration patterns (no white spots on lower portion of head, white margin and conspicuous stripes on 2nd dorsal and anal fins in T. trigonocephalus; white spots on lower portion of head, orange/red margin and no conspicuous stripes on 2nd dorsal and anal fins in T. bifasciatus) and salinity (T. trigonocephalus prefers salinities of 22 ppt and higher; T. bifasciatus generally found in brackish to freshwater regions of 0-22 ppt). It can be distinguished from T. barbatus by the presence of barbels on the head in the latter species.

Size: 11 cm.

Native Range: Brackish and marine waters of China, Korea, and Japan (Courtenay et al. 1986; Meng et al. 1994).

Interactive maps: Point Distribution Maps

Ecology: Chameleon gobies are benthic omnivores, similar to other goby species in California, primarily consuming amphipods, polychaete worms, and hydrozoans (Kwak et al. 2004).

Spawning of chameleon gobies in California generally occurs from May through September (Haaker 1979; Wang 2011). Males construct and guard nests in hard substrates such as clam/oyster shells or crevices in jetties, and opportunistically in discarded cans and bottles (Haaker 1979; Wang 2011). Chameleon gobies reach maturity in 1 year, with a maximum life span of 3 years (Dotu 1958).

Means of Introduction: The initial introduction may have been as fertilized eggs on introduced Japanese oysters (Courtenay et al. 1984, 1986, 1991) or from ballast water (Eschmeyer et al. 1983).

Status: Established in California. Recently, chameleon goby populations in San Francisco Bay have plummeted, possibly because of predation by yellowfin gobies (Meng et al. 1994). Because adults spawn 3-4 months after the piscivorous yellowfin goby, their young are vulnerable (Wang 1986).

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: Some reports in the literature referring to T. trigonocephalus collections made in freshwater in California (i.e., Raquel 1988; Meng et al. 1994) should actually refer to T. bifasciatus (Matern and Fleming 1995). This goby gets its name from its ability to rapidly change colors from a striped to a barred pattern (Eschmeyer et al. 1983). Tridentiger trigonocephalus is more common in marine environments than is T. bifasciatus; it is rarely found in salinities less than 22 ppt. (Matern and Fleming 1995; Fleming, personal communication).

Voucher specimens: California (CAS 27011); two other specimens, LACM 45016-1 and LACM 45688-1, should be re-examined in light of the discovery of T. bifasciatus.

References: (click for full references)

Akihito and K. Sakamoto. 1989. Reexamination of the status of the striped goby. Japanese Journal of Ichthyology 36(1):100-112.

Courtenay, W. R., Jr., D. A. Hensley, J. N. Taylor, and J. A. McCann. 1984. Distribution of exotic fishes in the continental United States. Pages 41-77 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.

Courtenay, W. R., Jr., D. A. Hensley, J. N. Taylor, and J. A. McCann. 1986. Distribution of exotic fishes in North America. Pages 675-698 in C. H. Hocutt, and E. O. Wiley, editors. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

Courtenay, W. R., Jr., D. P. Jennings, and J. D. Williams. 1991. Appendix 2: exotic fishes. Pages 97-107 in Robins, C. R., R. M. Bailey, C. E. Bond, J. R. Brooker, E. A. Lachner, R. N. Lea, and W. B. Scott. Common and scientific names of fishes from the United States and Canada, 5th edition. American Fisheries Society Special Publication 20. American Fisheries Society, Bethesda, MD.

Dotu, Y. 1958. The bionomics and life history of two gobioid fishes, Tridentiger undicervicus Tomiyama and Tridentiger trigonocephalus (Gill) in the innermost part of Ariake Sound. Scientific Bulletin of the Faculy of Agriculture, Kyushu University 16:343-358.

Eschmeyer, W. N., E. S. Herald, and H. Hamann. 1983. A field guide to Pacific Coast fishes of North America. Peterson Field Guide Series. Houghton Mifflin Co., Boston, MA.

Haaker, P. 1979. Two asiatic gobiid fishes, Tridentiger trigonocephalus and Acanothogobius flavimans, in southern California. Bulletin of the Southern California Academy of Science 78:56-61.

Herbold, B. A., A. D. Jassby, and P. B. Moyle. 1992. Status and trends report on aquatic resources in the San Francisco estuary. EPA Public Report, San Francisco, CA.

Kwak, S.N., S.H. Huh, and D.W. Klumpp. 2004. Partitioning of food resources among Sillago japonica, Ditremma temmincki, Tridentiger trigonocephalus, Hippocampus japonicus, and Petroscirtes breviceps in an eelgrass, Zostera marina, bed. Environmental Biology of Fishes 71:353-364,

Masuda, H., K. Amaoka, C. Araga, T. Uyeno, and T. Yoshino, editors. 1984. The fishes of the Japanese Archipelago. Tokai University Press. Text: i-xxii + 437 pp.; atlas: pls. 1-370.

Matern, S. A., and K. J. Fleming. 1996. Invasion of a third Asian goby species, Tridentiger bifasciatus, into California. California Fish and Game 81(2):71-76.

Meng, L., P. B. Moyle, and B. Herbold. 1994. Changes in abundance and distribution of native and introduced fishes of Suisun Marsh. Transactions of the American Fisheries Society 123:498-507.

Pondella, D.J., and Z.J.K. Chinn. 2005. Records of chameleon goby, Tridentiger trigonocephalus, in San Diego Bay, California. California Fish and Game 91(1):57-59.

Raquel, P.F. 1988. Record of the chameleon goby, Tridentiger trigonocephalus, from the Sacramento-San Joaquin Delta. California Fish and Game 74(1):60-61.

Shapovalov, L., A.J. Cordone, and W.A. Dill. 1981. A list of freshwater and anadromous fishes of California. California Fish and Game. 67(1): 4-38.

Wang, J. C. S. 1986. Fishes of the Sacramento-San Joaquin Estuary and adjacent waters, California: a guide to early life histories. Technical Report 9. Interagency Ecological Study Program for the Sacramento-San Joaquin Estuary, Sacramento, CA.

Other Resources:
Global Invasive Species Database Factsheet

Author: Leo Nico, Pam Fuller, and Matt Neilson

Peer Review Date: 6/23/2011

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.