An expedition to a remote South American rainforest has uncovered 24 previously unknown animals and rediscovered an armoured catfish thought to have died out.

One species thought to be entirely new was a toad with fluorescent purple markings.

Frogs, dung beetles, ants and fish were among the new finds. The catfish, thought to have been wiped out by goldmining more than half a century ago, was found alive and well. All were in a virtually untouched mountainous rainforest and palm swamps in Surinam.

During the expedition to the northern Amazonian region an international team of researchers conducted a wildlife survey. As well as the discoveries, they recorded 467 exotic creatures including panthers, monkeys, amphibians and the snail-eating snake Dipsas indica.

The dwarf suckermouth catfish, Hartiella crassicauda, was just found in the Paramaka Creek despite being thought to have been killed off by pollution. Jan Mol, a Surinam scientist involved in the expedition, was delighted and called for the fish to be classified officially as endangered as soon as possible by the World Conservation Union (known as the IUCN) before it is killed off for good.

The new species discovered by the explorers comprised the Atelopus toad, four Eleuthero-dactylus frogs, six fish species, 12 dung beetles and an ant species.

Researchers also recorded several creatures living in other places but never before found in Surinam, including the ant Cryptomyrmex longinodus.

The expedition to the Lely and Nassau plateaus in eastern Surinam, 80 miles (130km) from the capital Paramaribo, was organised and led by Conservation International.

Leeanne Alonso, from the group, which is based in the United States, said: “Our study will be vital . . . in determining how to promote economic development in Surinam while protecting the nation’s most valuable natural assets.”

Scientists from 13 universities and other organisations took part in the expedition and helped to draw up the report. In it they called for improvements in the management of the region’s ecology.

In particular, they called for illegal small-scale goldmining in the region and hunting to be curbed.

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