top of page
Tubenose goby (Proterorhinus semilunaris)

Tubenose Goby

(Proterorhinus semilunaris)

Report this Species!

If you believe you have found this species anywhere in Pennsylvania, please report your findings to iMapInvasives by submitting an observation record.

Species at a Glance

The tubenose goby is a small, bottom-dwelling fish that gets its name from its tubular-shaped nostrils. It feeds mainly on aquatic insects and although females can live for up to five years, males die immediately after spawning.


Its cylindrical body has small scales and a somewhat flattened underside, measuring 6-11 cm (2.4-4.3 in). It has a blunt and rounded snout with a wide mouth and large lips. Tubular-shaped nostrils extend just beyond the tip of the snout. Two pelvic fins are fused into a single suction cup-shaped fin, and the two dorsal fins lack spots. The body is light brown with darker brown blotches that can form vertical bars on the rear half of the sides. A triangular black spot is present at the base of the caudal fin, followed by two white spots.

Similar Species

While it may be confused with the round goby (Neogobius melanostomus), the tubenose goby is much smaller than the round goby and has tubular-shaped nostril extensions. The round goby has a black spot on the first dorsal fin and has very distinctive frog-like eyes that protrude from the top of the head. In addition, the tubenose goby does not feed on zebra mussels and its mouth is too small to be caught on fishing lines like the round goby. The tubenose goby may also be confused with the native sculpin; however, the sculpin does not have scales or pelvic fins that form a suction cup.


The tubenose goby lives in slightly brackish to freshwater. It actively defends nest sites created under rocks, logs, and shells in shallow areas of lakes and rivers with plenty of plant cover.


The tubenose goby was most likely introduced to the Great Lakes in the ballast water of ocean-going ships. Since it often resembles small bait fish, it can also be spread by boaters and fishermen who accidentally carry it from one body of water to another through bait buckets, bilge water, and plant debris.


Native to the Black and Caspian seas in Europe, the tubenose goby was first found in Lake Erie around 1990 and can now be found in lakes St. Clair, Erie, and Superior. There are currently no inland or Mid-Atlantic occurrences of this species other than the Great Lakes portion of Pennsylvania.


Note: Distribution data for this species may have changed since the publication of the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016), the source of information for this description.

Environmental Impacts

While its impacts are not yet known, the tubenose goby may be able to compete with and prey upon benthic species in a manner similar to the larger round goby. However, because it is small and not as aggressive, the tubenose goby may not be as detrimental as the round goby.


Information for this species profile comes from the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016).

bottom of page