Endangered Spotlight: Tidewater Goby

(Eucyclogobius newberryi)

By Hannah Orlove

Tidewater Goby.
Photo: Greg Goldsmith, USFWS

With tidewater gobies, females are in charge. During mating season, male fish dig burrows to lure potential mates. Females fight over the prospective dens.

After the females lay their eggs, the males spend a little over a week guarding hundreds of eggs, seldom venturing outside their burrows until the fertilized eggs have hatched.

Both sexes die soon after the breeding season, which typically starts in May and might end as late as December. A short lifespan makes for frequent spawning, peaking in summertime.

Characteristics

Tidewater gobies are about two inches in length, translucent with hints of molted gray, olive and brown.  They have large mouths that angle upwards, extending past their eyes.

The Tidewater Goby was first described in 1857, and is the only member of its genus within its larger family.

Habitat

The tidewater goby’s preferred environment is a brackish lagoon with fairly shallow water, a sandy bottom and cool temperatures. An estuary or marsh is typical.  However, the tiny fish is remarkably adaptable; the species has been found in waters even saltier than the ocean, over six feet deep, several miles inland, or with temperatures approaching eighty degrees Fahrenheit.

While sand is the preferred burrowing material, gobies have been observed on mud, silt, and even rock. Having some plants around helps as well, though more for protection or a place for their prey to breed. The diet of the Goby consists largely of small invertebrates, such as snails and insect larvae.

Range

The species’ range originally extended from San Diego to Del Norte County in Northern California, though that has been severely reduced in recent years. Today, most of the fish are found along the northern portion of the California coast.

Threats

As vulnerable as the fish are to predators such as frogs and larger fish, human habitat destruction is their biggest threat. While the goby can acclimate and survive in a wide range of situations, sudden environmental changes can be devastating to individual breeding populations. Damaging impacts include the introduction of non-native species and sudden increases in salinity levels.

In 1987, the tidewater goby was given protection by the California state government, and in 1994, by the federal government. Various projects and plans, such as habitat restoration and the reintroduction of the species to old breeding grounds, have been suggested. Designing new building developments with lesser environmental impact is another method that would help bring the Goby back to its former numbers.

 

Photo credits: Greg Goldsmith, USFWS