Sharknose goby

Background

Elacatinus evelynae is a very small, torpedo-shaped fish reaching a maximum length of 4 cm. It has a yellow stripe in front of each eye that joins to form a V near the tip of its snout, with black stripes running under the yellow ones from the snout, over the lower part of the eye to the end of the caudal fin. Its dorsal fin is split in two, with a rounded anterior fin and a flat posterior fin that lines up with its anal fin; the pectoral fins are almost circular, and all fins are transparent.

These gobies inhabit coral reefs in clear ocean waters at depths of 1 to 53 meters, within a temperature range of 22 to 27 °C. They are typically found around textured surfaces and coral heads containing large polyps, such as great star coral (Montastraea), mustard hill coral (Porites astreoides), and lettuce coral (Agaricia agaricites). They require textured surfaces to maintain their position against ocean currents, swell, and tides, as they are not strong swimmers.

As cleaner fish, they feed on ectoparasites and dead skin from other fish, as well as sponges, sea squirts, coral polyps, zooplankton, and free-living copepods. Females tend to clean and feed more than males, especially when accompanied by a large male, possibly due to mate guarding. They are monogamous and usually found in pairs near coral heads; both sexes show aggression toward same-sex intruders to protect their mates. Attempts to breed them in captivity have shown they do not produce eggs unless conditions are optimal, with little fluctuation in temperature and salinity.