Goby: Goby Fish ID, Aquarium Care and Invasive Round Goby

A goby is a small fish of the family Gobiidae, one of the largest fish families, with over 2,000 species in more than 200 genera (Wikipedia). The mark that identifies almost any goby is on the belly: the two pelvic fins are fused into a single disc-shaped sucker that lets the fish cling to rocks (Wikipedia).

Other useful checks:

• Where it sits: the sucker lets a goby cling to rocks (Wikipedia), and aquarium gobies burrow in sand (LiveAquaria), so look for a small fish resting on the bottom rather than swimming in open water.
• Size: most are small; the smallest, Trimmatom nanus, is under 1 cm when fully grown, and only a few species exceed 30 cm (Wikipedia).
• Not a sculpin: in the Great Lakes, native sculpins look similar, but a sculpin has two separate pelvic fins, while a goby's are fused (USGS).

For a photo ID, get a side view plus, if you can, a shot of the underside showing the sucker disc.

Gobies live in tropical and temperate coastal seas, brackish water and freshwater, and on coral reefs they make up about 35% of all fish species (Wikipedia). Some gobies share a burrow with a shrimp: the shrimp gets warning of approaching danger and the goby gets a safe home (Wikipedia). In the aquarium trade, the Yasha goby is sold as able to pair with most pistol shrimp species (Salty Underground).

Most are not. Of the 63 gobies listed by LiveAquaria on 25 September 2026, 62 are rated peaceful, 61 reef compatible, and 43 easy to care for. Salty Underground describes the yellow clown goby as small, peaceful and not aggressive, and notes that some gobies can be kept in groups.

LiveAquaria's care notes for gobies:

• they usually reach about 3 inches in captivity;
• a well-sealed lid is required, because gobies jump out of open tanks;
• provide plenty of rockwork and a coral-sand substrate so they can burrow.

Salty Underground describes several gobies, such as the ornate, bella, decorated sand and orange spotted diamond gobies, as sand sifters, which turn over the sand bed as they feed, and notes that the target mandarin needs specialised feeding.

Prices seen on 25 September 2026: at LiveAquaria, engineer goby from $16.99, yellow clown goby $24.99, neon goby $29.99, orange spotted goby $36.99, and a captive-bred Yasha white ray shrimp goby $125.99; at Salty Underground, yellow clown goby $24.99, ornate goby $39.99 and bella goby $99.99.

If you caught a goby in North American fresh water, it is most likely a round goby. How to recognise it:

• a distinct black spot at the rear base of the first dorsal fin (Wikipedia; USGS);
• pelvic fins fused into one scallop-shaped sucker (Minnesota DNR);
• a large head with bulging eyes and a torpedo-shaped body, light grey with dark blotches (Minnesota DNR);
• usually 3 to 6 inches, up to 10 inches (Minnesota DNR); USGS gives a maximum of 30.5 cm, with US fish rarely over 17.8 cm.

It is native to the Black Sea and Caspian Sea region and arrived in ballast water: the first North American catch was made by an angler in Sarnia, Ontario, on 28 June 1990 (Wikipedia). It competes with native mottled sculpins and eats fish eggs (USGS). It has also become food for native predators: in Lake Erie, burbot eat about 60% of each year's gobies, and the threatened Lake Erie watersnake has recovered partly by eating them (Wikipedia).

In the Great Lakes region, treat it as an invasive species and check your state's rules before you do anything else. In Minnesota, for example, the round goby is a prohibited invasive species: it is unlawful to possess, import, purchase, transport or introduce it except under a permit for disposal, control, research or education (Minnesota DNR). The DNR says round gobies spread mainly through the misuse and disposal of live bait, and asks anglers to dispose of unwanted bait in the trash.

Practical steps: do not carry it alive to another water body, do not use it as live bait, take a clear photo showing the dorsal-fin spot and the sucker, and report catches from new waters to your state natural resources agency.

Some gobies are food fish: Wikipedia lists the round, monkey, toad and grass gobies as commercially important in Russia and Ukraine. For fish from the Great Lakes or any other water, check local fish-consumption advice before eating, and check the invasive-species rules above before keeping one.

On venom: none of the sources we checked (Wikipedia, USGS, Minnesota DNR, LiveAquaria) describes gobies as venomous or lists venomous spines for them. That is not the same as saying every goby is harmless to handle or eat. If anyone feels unwell after handling or eating an unfamiliar fish, contact a doctor or poison control (in the US, 1-800-222-1222).

Research and drafting for this page were assisted by AI and checked line by line against the sources listed below. Every number names the organisation it comes from, and where sources disagree we say so instead of picking one silently. Prices and rules are given with the date we checked them (25 September 2026); they change, so confirm before you rely on them. If you find an error, tell us and we will correct it.