Proterorhinus semilunaris
The tubenose goby (*Proterorhinus semilunaris*) is a small-sized representative of the Gobiidae family, adapted to life in the quiet waters of the Delta. It is distinguished by its "nose-like" appearance and preference for vegetation-rich areas, unlike its relatives which prefer rocky or sandy zones. It is a discreet but very common fish in the channels and pools within the Danube Delta.
It has a laterally compressed body, slimmer than other gobies. The unique anatomical feature is the anterior nostrils, which are extended in the form of small tubes (like short whiskers) hanging over the upper lip. The colour is yellowish-brown, with numerous irregular stripes and spots that provide excellent camouflage among aquatic plants.
It is native to the Black Sea and Caspian Sea basins. In Romania it is very widespread throughout the Danube Delta, in floodplain marshes and in the Razim-Sinoe complex. It prefers still or slow-flowing waters with muddy bottoms and abundant submerged vegetation (hornwort, frogbit).
It is a solitary and relatively sedentary fish. It spends its time hidden among the leaves of aquatic plants, lying in wait for prey. Its diet consists mainly of small invertebrates: insect larvae (chironomids), small amphipod crustaceans and worms. It has a calm behaviour and is not as aggressive as the round goby.
Reproduction occurs between April and July. The male chooses a protected territory (a hollow reed stem, a cavity or even an object on the bottom) where the female lays the eggs. As with other gobies, the male guards and ventilates the eggs until hatching. Fry grow rapidly and reach sexual maturity in the second year of life.
The species is Least Concern (LC). Although of no interest for fishing, the tubenose goby is an important component of Delta biodiversity, serving as food for pike, perch and various bird species (herons, egrets). It is sensitive to massive organic pollution and destruction of shoreline vegetation zones.
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