Scientists have discovered six new species of fish with faces covered in tentacles hiding in the waterways of South America.

All of these unusual aquatic creatures are bristlenose catfish, relatives of the sucker-mouthed species often used in fish tanks to keep them clean of algae.

The fish were identified from specimens collected in the Guiana Shield region, an area encompassing parts of Venezuela, Colombia and Guyana.

Dr Lesley de Souza from the Chicago Field Museum came across the fish while examining museum samples belonging to what she thought were five species of catfish.

Instead of merely validating the existence of those species, the fish expert ended up bringing the total number she was dealing with up to 11 after examining their features and DNA.

Endangered sharks being served up in British fish and chip shops Show all 6 1 /6 Endangered sharks being served up in British fish and chip shops Endangered sharks being served up in British fish and chip shops Scalloped hammerhead shark Scalloped hammerhead shark fins were among those found being sold by an Asian food retailer in the UK. These sharks are endangered, and in parts of the Atlantic Ocean, their populations have declined by over 95% in the past 30 years. Istock/Janos Endangered sharks being served up in British fish and chip shops Spiny dogfish In the samples of takeaway fish and chips sampled, spiny dogfish made up 90% of those sold under the names huss, rock salmon and rock eel. Doug Costa, NOAA/SBNMS Endangered sharks being served up in British fish and chip shops Shortfin mako shark Another vulnerable species found in the dried shark fins tested in the British Asian wholefood retailer was the shortfin mako shark. Istock/Alessandro De Maddalena Endangered sharks being served up in British fish and chip shops Blue shark Blue shark was also found on sale in UK shops. This species is not as vulnerable as the others but is still listed as "Near Threatened" by the International Union for Conservation of Nature Istock/Howard Chen Endangered sharks being served up in British fish and chip shops Nursehound Around a quarter of the sharks being sold in UK fishmongers were nursehounds, another relatively safe species that is nevertheless classified as near threatened. Mario Antonio Pena Zapatería Endangered sharks being served up in British fish and chip shops Misleading names in fish shops The scientists behind the study investigating the prevalence of endangered shark meat on sale concluded that shops must stop selling these species under "umbrella terms" that hide their true origin. Istock

“We discovered six new species of really cool catfish from the Amazon and Orinoco River basins,” said Dr De Souza.

“They have tentacles on their snouts, they have spines that stick out from their heads, almost like claws, to protect themselves and their nests, and their body is covered with bony plates like armour.”

“They’re warriors, they’re fish superheroes.”

One of the new catfish species, Ancistrus patronus, named for the group’s paternal care of offspring. (Jonathan W. Armbruster)

The fish, which grow up to about 15cm long, use the tentacles on their snouts to gauge the quality of potential mates. If males have impressive tentacles, females will see them as high quality partners.

Dr De Souza and her colleagues documented their discoveries in the journal Zootaxa.

The scientists said it was crucial to understand how many undiscovered species are still lurking in the rainforests of South America, as the region is under threat from human expansion and the knowledge can be used to build a case for its defence.

Threats to the catfish and their habitats include intensive agriculture, deforestation and chemicals used in gold mining.

“They are sensitive to subtle changes in the environment, we have seen this at sites where they were plentiful and now scarce, this is due to habitat destruction,” said Dr De Souza.