''Eucyclogobius newberryi'', the northern tidewater goby, is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
goby
The Gobioidei are a suborder of percomorph fish. Many of these fishes are called gobies. It is by far the largest and most diverse order within the order Gobiiformes, and one of the most diverse groups of ray-finned fish in general.
The subord ...
native to
lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...
s of streams,
marsh
In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...
es, and creeks along the coast of
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
, United States. The northern tidewater goby is one of six native goby species of California. It is protected under the
Endangered Species Act
The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...
as an endangered species of the United States
[ since 1994.][
]
Etymology
The genus name translates as "true cycloid goby", referring to the scales, while the species epithet Specific name may refer to:
* in Database management systems, a system-assigned name that is unique within a particular database
In Taxonomy (biology), taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany) ...
is in honor of J. S. Newberry (1822–1892), an American geologist
A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...
, physician and explorer, who collected fishes for the species describer, Charles Frédéric Girard
Charles Frédéric Girard (; 8 March 1822 – 29 January 1895) was a French biologist specializing in ichthyology and herpetology.
Biography
Girard was born on 8 March 1822 in Mulhouse, France. He studied at the College of Neuchâtel, Switzerl ...
, just not this species.
Description
A small fish, only rarely longer than 5 cm (2 in), the northern 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 countershading
Countershading, or Thayer's law, is a method of camouflage in which animal coloration, an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptile ...
and tend to be mottled slightly darker on the dorsal side. The upper part of the first dorsal fin
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...
is clear or cream-colored, while the second dorsal is longer than the first, and close in size to the anal fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...
.
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
In geometry, a cycloid is the curve traced by a point on a circle as it Rolling, rolls along a Line (geometry), straight line without slipping. A cycloid is a specific form of trochoid and is an example of a roulette (curve), roulette, a curve g ...
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 northern tidewater goby by its more horizontal mouth and shorter rays in the anal fin compared to the 2nd dorsal fin.
Distribution and habitat
Their range extends from Tillas Slough at the mouth of the Smith River in Del Norte County, California
Del Norte County ( Spanish for "Of The North") is a county located at the far northwest corner of the U.S. state of California, along the Pacific Ocean adjacent to the Oregon border. Its population was 27,743 as of the 2020 census, down from ...
, south to Agua Hedionda Lagoon in San Diego County
San Diego County (), officially the County of San Diego, is a county in the southwest corner of the U.S. state of California, north to its border with Mexico. As of the 2020 census, the population was 3,298,634; it is the second-most populous ...
. While once recorded in at least 87 coastal locations, they are now gone from many, including San Francisco Bay
San Francisco Bay (Chochenyo language, Chochenyo: 'ommu) is a large tidal estuary in the United States, U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the cities of San Francisco, California, San ...
, although they can still be found nearby at Rodeo Lagoon in Marin County and in San Pedro Creek in Pacifica.
Despite the common name, this goby inhabits lagoons formed by streams running into the sea, as well as semi-closed estuaries. The lagoons are blocked from the Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
by sand bars, admitting salt water only during particular seasons, and so their water is brackish and cool. The northern tidewater goby prefers salinities of less than 10 ppt, but has been documented in waters with a salinity of 42 ppt. ''E. newberryi'' prefers water with mild temperatures (8 to 25 °C) and waters with a depth from 25 to 200 cm. Juveniles have been found as far upstream as 12 km, e.g. in Ten Mile River, Mendocino County
Mendocino County (; ''Mendocino'', Spanish language, Spanish for "of Antonio de Mendoza, Mendoza") is a County (United States), county located on the North Coast (California), North Coast of the U.S. state of California. As of the 2020 United S ...
, and San Antonio Creek and the Santa Ynez River, Santa Barbara County
Santa Barbara County, officially the County of Santa Barbara (), is a county located in Southern California. As of the 2020 United States census, the population was 448,229. The county seat is Santa Barbara, and the largest city is Santa M ...
, sometimes in sections of stream impounded by California Golden beavers (''Castor canadensis subauratus'') which provide ideal slow-moving water habitat for northern tidewater gobies.[ These fish also prefer sandy bottoms with depths of 20–100 cm, near emergent vegetation beds. These gobies often use thick patches of aquatic vegetation to hide in if threatened or disturbed.
The northern tidewater goby may be found in small groups of less than a dozen or occasionally in large aggregations of hundreds.
]
Behavior and reproduction
Spawning and reproduction is at its peak during spring and into late summer. However, in the southern region of its range where waters remain at a warmer temperature, ''E. newberryi'' will reproduce year round. The male then guards the eggs until they hatch, which is 9 to 11 days.
Male northern 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 - Camm 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 females lay between 300 and 500 eggs into a burrow dug out vertically by the male, which is 10 to 20 cm deep. Spawning locations are usually located out in the open away from any vegetation. 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.
Diet
The diet of the adult northern tidewater goby consists mostly of benthic invertebrates and local insects, though their diet's exact composition can vary by season. In some lagoon populations, gobies have been found to feed on seasonally available invasive New Zealand mud snails, reflecting the fish's adaptive foraging behavior to non-native species in its environment.
Conservation status
Habitat loss and modification are the main threats to ''E. newberryi''. The brackish areas where saltwater and freshwater meet are where they live usually, such as along the coast of California; this area has been altered by development. Barriers such as dikes and levees have been built to protect residents from potential flooding, but the creation of these barriers has reduced habitat for ''E. newberryi''. Other reasons for population declines are attributed to exotic fish and amphibians which have been introduced to the region. Many of these fish prey on ''E. newberryi'', and others outcompete them for food and habitat. The altering of streams flow with diversions has affected the salinity of the water and changed the habitat at creek mouths where ''E. newberryi'' has historically lived. Restoration projects have been started to bring populations back to a more stable number by making more habitat available, as well as providing protective areas. Some levees have been removed and exotic species reduction programs are being initiated.
The northern tidewater goby was listed by the state of California for protection in 1987, and federally listed in 1994. However, there has been some controversy over this, since many populations in its range are apparently secure, and the fish is even abundant at times. However, the fish's need for specific kind of habitat means that the populations are isolated from each other, and subject to extirpation due to various human activities, such as draining of wetlands, sand bar breaches for the purpose of tidal flushing, pollutant accumulation in lagoons, and so forth. Even so, studies have shown that it is a resilient species, and populations have been successfully restored to wetlands that have been protected.
References
{{Authority control
Gobionellinae
Endemic fauna of California
Taxa named by Charles Frédéric Girard
Fish described in 1856