How did lookdown and stargazer fishes get their names?
Lookdowns and stargazers have different perspectives on their aquatic worlds, so to speak, since their eyes are positioned in somewhat unusual places. Both fish take their names from the way their eyes are situated. The lookdown, Selene vomer, appears to be gazing down its nose as it swims.
It has a very compressed or thin body with a very long or steep forehead. It’s that steep forward that accounts for its downward-cast eyes. The lookdown is a member of the jack family and has a metallic coloring: bluish on its back and silvery or golden elsewhere. Its coloring might be one reason why the lookdown also is called moonfish for the Greek goddess of the moon, Selene.
Long reed-like strands called filaments extend from the dorsal spines of young lookdowns help them hide in the grasses of salt marsh. Young lookdowns also have longer pelvic fins to aid in camouflage.
The lookdown grows to about 16 inches and can be found in shallow coastal waters from Maine to Uruguay.
While Selene vomer casts a downward eye, the stargazer appears to be looking in the opposite direction. There are two families of stargazers: the smaller family Dactyloscopidae and the larger family Uranoscopidae. Members of each family are characterized by eyes located on top of the head, so it seems as though they are constantly looking skyward. The speckled stargazer, Dactyloscopus moorei, is one of several stargazers found off North Carolina. Its eyes are actually on short stalks. It is sand-colored with dark, evenly scattered speckles on its back. It burrows in soft, sandy bottoms, where it blends in with the “scenery” to surprise its prey. The speckled stargazer grows to about 3 inches.
At least three varieties of stargazers from the family Uranoscopidae are found in North Carolina waters: the northern stargazer, Astroscopus guttatus, the southern stargazer, Astroscopus y-graecum, and the lancer stargazer, Kathetostoma albigutta. These medium-sized fish have very flat heads and very vertical mouths.
In addition to the unique placement of their eyes, both northern and southern stargazers produce electricity from a muscle behind the eye. It is thought that these fish create an electrical field that gives a “shocking” early warning signal to predators.
These three stargazers lurk on the bottom of the ocean, sometimes partially burying themselves to wait for prey.