Tidewater goby
Encyclopedia
The tidewater goby Eucyclogobius newberryi is a goby
(Gobiidae) native to lagoon
s of streams along the coast of California
.
. The tidewater goby is the sole member of its genus. The first description was in the genus
Gobius
(Gobius newberryi) by Girard in 1854. The full scientific name is thus now: Eucyclogobius newberryi (GIRARD, 1854).
in Del Norte County, California
, south to Agua Hedionda Lagoon
in San Diego County. While once recorded in at least 87 coastal locations, they are now gone from many, including San Francisco Bay
.
and tend to be mottled slightly darker on the dorsal side. The upper part of the first dorsal fin
is clear or cream-colored, while the second dorsal is longer than the first, and close in size to the anal fin.
The large mouth extends back to or past the posterior edge of the eye, and is angled upwards. The eyes are spaced far apart. Unusually among gobies, the scales are cycloid instead of ctenoid; they are always absent from the head, and often from the underside too.
Breeding individuals will demonstrate color changes, with the males becoming more black with white spots as females become tan or reddish-brown with golden or dark-brown sides. Females may also take on a darker color while fighting.
Similar fish include the longjaw mudsucker
, which can be distinguished from the tidewater goby by its more horizontal mouth and shorter rays in the anal fin compared to the 2nd dorsal fin.
by sand bars, admitting salt water only during particular seasons, and so their water is brackish and cool. The tidewater goby prefers salinities of less than 10 ppt THIS. Juveniles have been found as far upstream as 12 km, e.g. in Ten Mile River, Mendocino County
, and San Antonio Creek and the Santa Ynez River
, Santa Barbara County
, sometimes in sections of stream impounded by California Golden beavers (Castor canadensis subauratus) which provide ideal slow-moving water habitat for tidewater gobies. These fish also prefer sandy bottoms with depths of 20–100 cm, near emergent vegetation beds.
The tidewater goby may be found in small groups of less than a dozen or occasionally in large aggregations of hundreds.
If the female is successful (which may be infrequent - Cam Swift reports that 23 observed courtships resulted in only a single successful entry into the burrow by the female,) she will lay eggs on the burrow's sides and roof. The male protects the eggs for 9–10 days before they hatch. Although their life expectancy is not well known, tidewater gobies may live for only a year.
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...
(Gobiidae) native to lagoon
Lagoon
A lagoon is a body of shallow sea water or brackish water separated from the sea by some form of barrier. The EU's habitat directive defines lagoons as "expanses of shallow coastal salt water, of varying salinity or water volume, wholly or partially separated from the sea by sand banks or shingle,...
s of streams along the coast of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
Taxonomy
The genus name translates as "true cycloid goby", referring to the scales, while the species epithet is in honor of J. S. NewberryJohn Strong Newberry
John Strong Newberry was a American geologist, physician, explorer, author, and a member of the Megatherium Club at the Smithsonian Institution in Washington, D.C....
. The tidewater goby is the sole member of its genus. The first description was in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Gobius
Gobius
Gobius is a genus of fish in the Gobiidae family. It contains the typical gobies, being the type genus of its subfamily and family, and the namesake genus of its suborder .It contains the following species:...
(Gobius newberryi) by Girard in 1854. The full scientific name is thus now: Eucyclogobius newberryi (GIRARD, 1854).
Geographic Range
Their range extends from Tillas Slough at the mouth of the Smith RiverSmith River, California
Smith River is a census-designated place in Del Norte County, California, United States. It is located north-northeast of Crescent City, east of the mouth of the Smith River, at an elevation of 52 feet . As of 2010, the population was 866. The ZIP Code is 95567...
in Del Norte County, California
Del Norte County, California
Del Norte County is a county located at the far northwest corner of the U.S. state of California on the Pacific adjacent to the Oregon border. As of the 2010 census, it had a population of 28,610. The county seat is Crescent City, the county's only incorporated city. Del Norte is the abbreviated...
, south to Agua Hedionda Lagoon
Agua Hedionda Lagoon
The Agua Hedionda Lagoon is a lagoon in Carlsbad, California, that is fed by the Agua Hedionda Creek. Stewardship of much of the lagoon is held by the Encina Power Station and its owner NRG Energy...
in San Diego County. While once recorded in at least 87 coastal locations, they are now gone from many, including San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
.
Physical description
A small fish, only rarely longer than 5 cm (2 in), the tidewater goby is elongate with a blunt tail. Color is a mottled gray, brown, or olive; living fish are translucent or mostly transparent. Tidewater gobies, like many fish, exhibit countershadingCountershading
Countershading, or Thayer's Law, is a form of camouflage. Countershading, in which an animal’s pigmentation is darker dorsally, is often thought to have an adaptive effect of reducing conspicuous shadows cast on the ventral region of an animal’s body...
and tend to be mottled slightly darker on the dorsal side. The upper part of the first dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
is clear or cream-colored, while the second dorsal is longer than the first, and close in size to the anal fin.
The large mouth extends back to or past the posterior edge of the eye, and is angled upwards. The eyes are spaced far apart. Unusually among gobies, the scales are cycloid instead of ctenoid; they are always absent from the head, and often from the underside too.
Breeding individuals will demonstrate color changes, with the males becoming more black with white spots as females become tan or reddish-brown with golden or dark-brown sides. Females may also take on a darker color while fighting.
Similar fish include the longjaw mudsucker
Longjaw mudsucker
The longjaw mudsucker Gillichthys mirabilis is a goby of the Pacific Ocean coast of California and Baja California, noted for its extremely large mouth and ability to survive out of water for short periods....
, which can be distinguished from the tidewater goby by its more horizontal mouth and shorter rays in the anal fin compared to the 2nd dorsal fin.
Habitat and Diet
Despite the common name, this goby inhabits lagoons formed by streams running into the sea. The lagoons are blocked from the Pacific OceanPacific 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...
by sand bars, admitting salt water only during particular seasons, and so their water is brackish and cool. The tidewater goby prefers salinities of less than 10 ppt THIS. Juveniles have been found as far upstream as 12 km, e.g. in Ten Mile River, Mendocino County
Mendocino County, California
Mendocino County is a county located on the north coast of the U.S. state of California, north of the greater San Francisco Bay Area and west of the Central Valley. As of the 2010 census, the population was 87,841, up from 86,265 at the 2000 census...
, and San Antonio Creek and the Santa Ynez River
Santa Ynez River
The Santa Ynez River is one of the largest rivers on the Central Coast of California. It is long, flowing from east to west through the Santa Ynez Valley, reaching the Pacific Ocean at Surf, near Vandenberg Air Force Base and the city of Lompoc....
, Santa Barbara County
Santa Barbara County, California
Santa Barbara County is a county located in the southern portion of the U.S. state of California, on the Pacific coast. As of 2010 the county had a population of 423,895. The county seat is Santa Barbara and the largest city is Santa Maria.-History:...
, sometimes in sections of stream impounded by California Golden beavers (Castor canadensis subauratus) which provide ideal slow-moving water habitat for tidewater gobies. These fish also prefer sandy bottoms with depths of 20–100 cm, near emergent vegetation beds.
The tidewater goby may be found in small groups of less than a dozen or occasionally in large aggregations of hundreds.
Behavior and Reproduction
Male tidewater gobies burrow into sand and mud in the spring, cementing together grains of sand with a mucous, and shutting the burrow off from the waters above with a mucous and sand plug. Females will become aggressive during the spring and fight over a potential mate, slapping each other with their tails and biting when posturing is insufficient to drive their rivals away. The female will then attempt to entice the male to open his burrow.If the female is successful (which may be infrequent - Cam Swift reports that 23 observed courtships resulted in only a single successful entry into the burrow by the female,) she will lay eggs on the burrow's sides and roof. The male protects the eggs for 9–10 days before they hatch. Although their life expectancy is not well known, tidewater gobies may live for only a year.