Echeneis naucrates

Actinopterygii: The Actinopterygii, or ray-finned fishes, constitute a class or subclass of the bony fishes. The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines ("rays"), as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii. In terms of numbers, actinopterygians are the dominant class of vertebrates, comprising nearly 99% of the over 30,000 species of fish. (Wikipedia)

Brackish: Brackish water or briny water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. (Wikipedia)

Subtropical: The subtropics are geographic and climate zones located roughly between the tropic circle of latitude (the Tropic of Cancer and Tropic of Capricorn) and the 38th parallel in each hemisphere. Subtropical climate regimes can exist at high elevations within the tropics, such as across the Mexican Plateau and in Vietnam and Taiwan. (Wikipedia)