The Slow goby (Aruma histrio) is a species of gobies, endemic to the Gulf of California on the west coast of North America. It inhabits crevices in rocks and can be found in tide pools down to a depth of around 14m (46feet). This species grows to a maximum length of 6.5cm (02.6inches) SL. This species is the only known member of its genus.
It is brown with 6-7 white bars along its side, with some bars weak or missing. There is a narrow white bar at the base of its pectoral fin, followed by a dark brown bar. It is elongated and somewhat compressed. Its large head is flattened with swollen cheeks and a large mouth. It has a pore between its eyes, and two small pores on its preopercle. Its tail fin is long and rounded without scales or a lateral line.
The slow goby inhabits rocky crevices in tide pools and under cobble in shallow water. The larvae are usually found around sargassum. It needs a temperature of 20.8-23.8 degrees Celsius (69.4-74.8 degrees Fahrenheit). Adults are benthic.[1]