Sargassum fish are present; the gills open as pores near the base of the pectoral fins. The anal fin has no spines and seven to 13 soft rays. The pelvic fins are large and the pectoral fins have 9-11 rays and are stalked and able to grip objects. The outer rays of the tail fin are simple, but the central rays are forked. The sargassum fish has a cosmopolitan distribution in tropical and subtropical seas down to a depth around . It is found in parts of the Atlantic Ocean and the Indo-Pacific Ocean, where drifting seaweed accumulates. In the western Atlantic,
Sargassum develop in the axils of leafy laminae. It is self-fertile. In summer 2015, large quantities of different species of "Sargassum" accumulated along the shores of many of the countries on the Caribbean Sea. Some of the affected islands and regions include the Caribbean coast of Mexico, the Dominican Republic, Barbados, and Tobago. Another large outbreak occurred in 2018. The algae wash ashore, pile up on beaches, and decay, often causing a foul odor, releasing fumes of sulphur compounds that rust metals, can turn taps black in shore houses, damage modern conveniences, and cause respiratory problems, particularly for asthmatics. A doctor