Stargazers are a carnivorous group of vacuuming, toxin-yielding, sometimes electrocuting and occasionally bioluminescent fish! Stargazers are not a single species of fish, rather, are a world-wide group of more than fifty different species belonging to the family, Uranoscopidae.
‘Uranoscopidae’ is derived from the Greek word ‘ouranoskopos’, translating to ‘observing the heavens’. This refers to the placement of this marine animal’s eyes on the top of their head which enable them to stare upwards from the bottom of the ocean floor. Using their pectoral fins to shimmy their way into the sand or mud, stargazers bury themselves in the sea floor, leaving only their eyes and mouth exposed.
Contrary to what their name suggests, there is no evidence to support that stargazers use their upward-facing eyes to admire the starry night. Instead, their top-mounted eyes enable them to watch for passing prey whilst hiding in the sand, watching, waiting. When the stargazer’s prey gets close enough, the predator will swiftly lunge towards its prey, using its mouth like a vacuum to suck up its food – sometimes whole – all within a matter of seconds!
The Kathetostoma laeve, also known as the “common stargazer”, is the only known species of stargazer in Victoria’s marine coastal waters. The common stargazer can be found along most of the south and south-east coast of Australia, being present from Western Australia, all the way to the top of New South Wales.
Our local stargazer is one of the many marine animals which has bioluminescent capabilities, lighting up the ocean at night! A blue-green glow often lines the common stargazer’s fins, outlining the tail, pectoral fins and dorsal fins. This light fluorescence may serve a similar function to the light organ found in anglerfish, which helps the predator to lure curious prey towards the light.
Some stargazers are known for having toxin-producing spines on their back. This toxin is not for hunting their prey, but serves as a protection mechanism against other predators, or, an unlucky human foot! Although there are tales of the common stargazer’s sting being deadly to humans, there are no official reports verifying this. However, there have been reports of this species biting night divers!
Though Victoria is home to just one stargazer species, there are many other species of stargazer that live around the coast of Australia, many of which boast weird and wonderful adaptations. For example, the armed stargazer (Uranoscopus affinis), which is able to deliver electric shocks! Like electric eels, certain stargazer species can generate electricity to deter predators. While humans can feel the shock, it’s not strong enough to cause serious harm, especially when compared to the more powerful jolt of an electric eel.
In addition to glowing lures, toxic spines and stunning shocks, some stargazers have protractible flesh on the inside of their mouth that looks like a sea worm. This “worm” can be used as bait, luring hungry fish, cephalopods and crustaceans right into its mouth!
Although stargazers may not have an appreciation for the night sky, they’re pretty well-equipped to stealthily hunt prey, whilst also defending themselves from predators. Stargazers are just one of the many groups of marine creatures who call the ocean floor “home”, and are an example of why we should look after every aspect of the ocean, including the bottom of the sea!
Written by Alaska O’Leary
If you would like to learn more about the huge diversity of life that can be found along our coasts and shorelines, please contact our Education Director at education@dolphinresearch.org.au for a public event, school holiday program or school incursion/excursion.
