There are fifty-one species of stargazer fish and eight genera. They’re found around the world in both shallow and deep water but are rarely found beyond 60 meters.
These less-than-beautiful fish are also quite skilled hunters. Their camouflage and top-facing eyes and mouth help them blend in and stay hidden in the ocean’s sandy floor till they can ambush an unsuspecting fish, crab, or squid.
Appearance
Stargazers are small, perciform fish or ray-finned fish that are the largest order of vertebrates. The group includes over 10,000 species in the world’s oceans.
They have eyes on the top of the head (hence the common name) and a large, unusual upward-facing mouth that gives them a strange appearance. They have long fins, especially for their size, and some species have a worm-like lure growing out of their mouths. The various species may or may not have dorsal spines as well.
Stargazers have two venomous spines growing out of their backs above their pectoral fins. In addition to this means of defense, two species of stargazer can cause electric shocks. The two species are Astroscopus and Uranoscopus, both of which are unusual among electric fish because they don’t have electroreceptors.
Their bodies are flattened (in order to blend in more seamlessly with the ocean floor) and usually shades of light and dark brown and grey. Some species have patterns of spots on their backs and around their eyes, while others have more defined thick stripes. They’re also usually lighter on the bottom of their bodies and darker on the top, a type of coloring known as countershading.
Countershading is common to various marine species and helps disguise fish and larger animals from predators. If viewed from the bottom, the lighter coloring helps the animal blend in with the light coming through the ocean’s surface. If viewed from above, the darker coloring blends in with the ocean floor.
Habitat
Stargazers live around the world but are most commonly found in the Atlantic and Pacific oceans. They are found in shallow and deep waters but usually prefer warmer seas. They spend most of their lives on the ocean floor near bays and estuaries, commonly at depths of around 35 meters or so.
They are known for burying themselves using their side fins like shovels, up to their eyes on the top of their head, in the sand where they can wait for prey to pass by or to protect themselves from other animals. Their brown/grey coloring also helps these unusual fish disguise themselves on the ocean floor.
Diet
Stargazers eat a variety of prey, including small fish, crustaceans, squids, and crabs. These various marine animals are easy to come upon, especially as the stargazer uses its preferred hunting method of burying itself on the sandy ocean floor.
Stargazers use ambush techniques in order to capture their prey. They lay in wait, buried underneath the sand, for a suitable meal to pass over their heads before using their relatively large mouth like a vacuum. Their upward-facing eyes and mouth make latching on to a passing smaller fish or a crab very easy.
Interestingly, some species also have a lure attached to the bottom of their mouths. This is another feature they can use to attract prey (because it looks like a worm). They extend this lure out of their mouths, and the sand in which they’re hiding and passing fish will see it as a worm and be drawn to it.
Reproduction and Lifecycle
Stargazers usually spawn between May and June, laying eggs in the sand and mud on the seabed that later float to the surface. Their young reach sexual maturity quickly, being able to reproduce four to eight months after hatching.
Stargazers live for between four to six years, with the females typically living longer due to less aggressive behavior.
Threats
Stargazers are not a common food source around the world, meaning that overfishing (one of the major threats to other fish species) does not impact them. But they are still caught and eaten as a delicacy in some areas of the world. Plus, they are at threat from bycatch practices. That is the process by which fish are accidentally caught up in nets meant for other marine creatures. This can result in significant impacts on population numbers worldwide.
Facts about Stargazer Fish
- There are eight genera of stargazers and 50 species of fish in this family.
- All stargazers live in saltwater.
- Stargazers are venomous.
- Stargazers are considered a delicacy in some places.
- They are ambush hunters.
- Two genera of stargazers can cause electric shocks.
- The two most common species of Stargazers are Northern Stargazers (Astroscopus Guttatus), and Southern Stargazers (Astroscopus y-graecum)
- Part of the Stargazers scientific name, Astrocopus, means “one who aims at the stars”
FAQs
Are stargazer fish poisonous?
Yes, stargazers have two large poisonous spines on their backs. These act as a defense mechanism and deter predators from eating them. But, when cooked, the poison dissipates, making the fish edible.
Why should you not get too close to a stargazer fish eyes?
Two genera of stargazers have electric organs around their eyes. If you step on this part of the fish, you might experience an electric shock. But, the shock is minimal and not dangerous for human beings, and stargazers generally won’t move or shock divers unless disturbed.
Can stargazers be eaten?
Yes, despite their poisonous spines, they are considered a delicacy in some cultures. The position dissipates during the cooking process, making them safe to eat. These fish are not a common food source in the world’s oceans, so it’s unlikely that most people will ever have the chance to eat or cook one, partially due to anglers not being fond of their sharp spines.
What happens if you step on a stargazer fish?
If you step on a stargazer, you’re likely to come into contact with its two poisonous spines. You might also experience a slight electric shock if you’ve stepped on one of two specific stargazer genera.
What fish buries itself in the sand?
There is a variety of fish that bury themselves in the sand. Stargazers are one of them. Others include Cory and Eels. Fish that bury themselves in the sand use it in order to hide from predators and from potential prey. If they are successfully camouflaged, a buried fish can ambush another passing fish, crab, or other potential meal.
