Stargazers are a group of around 50 different fish species, each one as odd as the next.
These strange-looking creatures hide in the sand waiting for unwitting prey to swim above them before they launch an ambush and gobble them up.
To help them keep watch, both eyes are located on the top of their head, as if they’re constantly looking up towards the stars – hence the name.
Buried in the sand, they’re not just making themselves invisible to prey. Shuffling under the sediment also creates a secret hiding spot to keep them safe from predators. But, just in case, some species also have extra lines of self-defence: they have venomous spines and can deliver an electric shock when they need to.
What are stargazer fish?
Stargazer fish can be recognised by their strange faces, which look – let’s admit it – rather grotesque to humans.
However, this strategic adaptation makes them great at hide-and-seek. Their upward-facing eyes and nostrils allow them to bury themselves into the sandy bottom and wait – watching the world pass by while remaining unseen – until a tasty morsel makes the mistake of swimming too close.
They usually eat small fish, crabs and other crustaceans. When their prey is in range, they engulf them.
How do stargazer fish breathe?
Unlike many other types of fish, stargazers can breathe through their nostrils rather than taking in water through their mouth and passing it over their gills.
To stop sand getting up their nose when they breathe, these unusual fish have fleshy fringes around their nostrils. They have similar fringing around their mouth to prevent them getting mouthfuls of sand while hiding under the seabed.
Where are stargazer fish found?
Stargazer fish live on the seafloor in sandy, silty, muddy or gravel habitats where they can easily hide.
With so many different species, these fish are spread broadly around the world: in the Atlantic and Pacific Oceans as well as the Black, Mediterranean and Red Sea. They aren’t found in polar waters.
How do stargazer fish eat?
When a fish passes by close enough to be gobbled up, these lay-in-wait predators open their huge mouth, creating a vacuum that sucks the poor victim right into their gob. These beastly fish can swallow prey whole.
Not content with waiting patiently for their dinner, some species give themselves a little helping hand. Somewhat horrifyingly, they have a lure growing out of their face that they can use to trick prey into coming closer. Wiggling this piece of skin to make it look like a juicy worm fools hapless fish into coming in for a bite. By the time they realise their mistake, it’s too late – they’ve become the stargazer’s lunch.
How do they dig themselves into the sand?
Hiding in the sand is vital if these fish are to find food so they’ve developed a clever way of burying themselves.
They have large pectoral fins which they can use like a spade to shovel sand out of the way as they bury their flat bodies under the substrate.
Their brownish colour also helps them blend in with the sand around them, keeping them safely hidden from both predators and prey.
How do stargazer fish protect themselves?
Some species of stargazer have shocking self-defence skills – literally. They have a special organ behind their eyes that creates an electrical charge, which they usually use to protect themselves from potential threats. This organ forms when they start to mature into adults. The strength of the shock it delivers varies but can be up to 50 volts. Although this is much lower than the 230 volts found in household wiring in the UK, it could still give you a nasty jolt so divers and fishers should always avoid touching this fish.
Some species also have venomous spines above their pectoral fins.
How do they reproduce?
These bottom dwellers spawn from late spring to early summer. The eggs float to the surface and hatch into larvae which live in the open ocean while they grow.
Once they become large enough, the juveniles return to the bottom where they will live their adult lives. As they mature, they develop the electric organ used for self defence and their eyes migrate from the side of their head to the top.
A stargazer fish’s special features
- Bulging eyes
- Large, flat heat
- Eyes and nostrils on the top of the head
- Electric organ behind eyes
- Slanting mouth
- Fringes around the mouth
- Brownish body, sometimes with white dots
Stargazer fish: at a glance
- Scientific family name: Uranoscopidae
- Nicknames: Stargazer
- Length: Up to 56 cm in some species
- Average lifespan: Dependent on the species but these fish live for several years
- Weight: Up to 9kg
- Depth: Varies, some species can be found as deep as 385 metres
Main image: whitemargin stargazer in Lembeh Strait, Indonesia/Getty
More peculiar sea creatures from around the world
- Gulper eel - with its enormous jaws and a tail that glows pink
- Pineapple sea cucumber – with its thick, spiky skin that resembles a pineapple
- Giant isopod – it has 14 legs, grows up to a metre long and can take on a shark
- Hawaiian bobtail squid – which disguises itself as a moonbeam and dies as soon as it breeds
