Things Are Looking Up
Southern stargazers have adapted to life under the sand.
By Karina Kumar
Southern stargazer might sound like a Texan staring up at the night sky looking for constellations, but it actually refers to a special fish whose eyes sit on top of its head.
The southern stargazer, Astroscopus y-graecum, is considered a demersal fish, or groundfish, because because it dwells and reproduces along the sandy bottoms of the ocean. Astroscopus is a Latin term that means “one who targets the stars” or “one who shoots for the stars.” The fish hide under the sand using their coloring (brownish with white speckles) to blend in. Their mouth, nostrils and eyes sit on top of their head and are the only things visible.
When the stargazer sees its prey of choice, generally a smaller fish unaware of the hidden predator, it will quickly sneak out of its hiding spot and swallow the fish whole.
Southern stargazers can grow upwards of 17 inches and are known for their distinct white speckles. They live along the coast from North Carolina all the way down to South America. Their colder-weather counterparts, the northern stargazers, are similar to southern stargazers in their behavior and history but live further up the East Coast.
The southern stargazer has developed various adaptations for its life in the sand. As small guppies, their eyes are on the sides of their head, like other fish, but as they transition to adulthood, their eyes migrate to the top of their head so they can hide in the sand and still easily see. Unlike most fish, they breathe by bringing water in through their nostrils; both the nostrils and mouth have fringe that help prevent sand from coming in when they breathe. They have also developed pectoral fins that dig like shovels so they can quickly bury themselves to hide from a predator or wait for prey.
Along with their interesting adaptations for sand, southern stargazers have unique defense mechanisms, including venomous spines above their pectoral fins that act as a first form of defense. But the truly special thing about this species is the electric organs behind their eyes that can produce a shock of up to 50 volts. Unlike other electric fish, stargazers do not use this skill to shock prey, or detect them using electrolocation. Instead, the electric shock is used only as a defense if a predator gets too close.
Their ability to produce a shock should deter you from disturbing these fish. On top of that, stargazers have been known to bite divers who get too close (especially at night), though they generally leave divers alone. So, be careful if you're diving near these fish, and be especially careful handling them if you happen to catch one while fishing.
Common name:
Southern stargazer
Scientific name:
Astroscopus y-graecum
Habitat:
Sandy, silty or rubble-covered ocean floors from North Carolina down to South America.
Diet:
Other fish and invertebrates
Did you know?:
In a 1979 study, stargazers' bodies were found to change color to a light yellow-gray when they are hungry (at least in an aquarium environment).
