Frillfin goby is then protected by the male until the eggs hatch. These males are often extremely territorial, and chase off intruders. The young gobies can grow to an average of about 7.5 cm in length. This species is found in the Gulf of Mexico. It prefers inshore shallows especially near rocks and pilings. Although rare, the frillfin goby has been seen in the aquarium trade. Frillfin goby The frillfin goby ("Bathygobius soporator") is a species of marine fish in the genus "Bathygobius". The frillfin goby is a usually dark colored goby with mottled coloring of black, gray, and tan, but body
Sand goby rounded. In males, there is a conspicuous dark spot on the anterior dorsal fin and in both sexes there is a black patch on the caudal peduncle. The general colour is sandy brown with indistinct dark blotches and reticulations on the dorsal surface and dark striations on the pale fins. The colour of the male darkens during the breeding season and his fins become more coloured. The average size is about . The sand goby normally lives at greater depths than the common goby. It feeds on small invertebrates living on the seabed especially amphipods. It is well camouflaged and