The Galaxiidae family of freshwater fishes is unique to the Southern Hemisphere. It originated in the vast continent of Gondwana, and when it broke apart they floated off, on the different tectonic plates that now make up Africa, South America, and Oceania (Australia, Tasmania, New Zealand, and New Caledonia). They evolved between 235 and 21 Ma, and some species have a life cycle where the larvae develop in the ocean and then migrate upstream into freshwater habitats. This adaptation could have helped them disperse between continents even after Gondwana broke up.
In South America they are found in the cold and temperate waters of Chile, Argentina and the Malvinas-Falkland Islands, as well as Tierra del Fuego Island.
Their name comes from the word "galaxy" because of the star-like patterns on their bodies. They lack scales and their skin is smooth and slippery.
The South American galaxids form three genera and eight species many of which overlap in their territoral ranges. In Patagonia, the Galaxias maculatus (known as puye or puyen chico) lives close to the sea coast in estuarine areas. while the G. platei is found in lakes and rivers that feed them. The other species (G. globiceps, Aplochiton zebra, A. marinus, A. taeniatus, Brachygalaxias bullocki, and B. gothei) are found in smaller numbers and less frequently.
The Galaxias platei, also known as puyen grande, lives in lakes, in deep areas to avoid being caught by the other endemic fish species like the perch (Percichthys trucha), but are now prey of the introduced trout (brown, rainbow, brook, lake trout), and the salmons that now prevail in the Patagonian lakes, rivers and coastal waters.
They are well adapted to aquatic environments with low oxygen content and to cold waters. This may have helped them adapt to their benthic (deep) habitat and to the freezing conditions of the Ice Ages.
Galaxias platei can live up to 20 years and they grow to a size of 35 cm (3 ft 2 in.), juveniles aged 2 to 4 years-old have sizes that range from 10 to 18 cm (4 to 6 inches).
They are not seen frequently and as an endangered species, fishing is not allowed. In all my decades of fishing trout in the Patagonian lakes, I never once encountered one, they are a rare sight in Patagonia.
Their dwindling numbers also affects the Patagonian otter or huillin, who had adapted to hunt them. Swifter trout and salmon are harder to catch. Huillines also suffer from the introduction of the salmonidae, and the loss of the galaxidae. This shows how exotic species can alter a balanced ecosystem.
They feed off the crabs and shrimps that live in the Patagonian lakes, and formed part of the diet of the Patagonian otter, the huillín.
The largest galaxid is found in New Zealand, it is known as the giant kōkopu (Galaxias argenteus), like those in Patagonia, it is also a threatened species endemic to New Zealand. It is roughly twice the size of the puyén, reaching up to 58 cm (23 in) and weighing up to 2.7 kg (6 lb).
I doubt that the puyen could have inspired any Patagonian lake monster myths, but I admire them as tough survivors in the cold, clear Patagonian waters.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2025 by Austin Whittall ©
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