The International Union for Conservation of Nature (IUCN) has just declared the species Sympterichthys unipennis officially extinct. Native to Australia, this marine fish which has the particularity of “walking” with its fins, has not been observed for 200 years.

Last January, a study announced the extinction of the Chinese swordfish, a fish endemic to the Yangtse-Kiang river that could measure up to seven meters long. Missing from radars since 2003, Psephurus gladius had become the first species to be declared extinct for the 2020 decade. Unfortunately, it will not be the last.

The International Union for Conservation of Nature (IUCN) has just added another fish to the list of missing: Sympterichthys unipennis. This vertebrate which belongs to the family of Lophiiformes was formerly widespread off the coasts of Australia and Tasmania from which it originates. It was even one of the first scientifically described fish species in the region in the early 19th century.

It must also be said that the animal is unusual. Its head is topped with a triangular crest similar to an Iroquois cup and its body is endowed with pectoral and pelvic fins which it uses to “walk” in the seabed. In the early 1800s, French naturalist and explorer François Péron collected a specimen from Tasmanian waters to document the species.

Since then, this fish has become a unique specimen. Despite intensive research, scientists have never again managed to observe Sympterichthys unipennis in its natural environment, ultimately pushing IUCN to declare the species extinct.

The first marine fish declared extinct during the modern era

This extinction is an alarm signal for biodiversity. S. unipennis is indeed the first species of marine bone fish to be declared extinct during the modern era, according to the IUCN. “Some people say that the ocean is too big for marine life to go out,” Jessica Meeuwig, says director of the Center for Marine Futures at the University of Western Australia. “But the industrialization of the ocean through fishing, mining, oil and gas, shipping and infrastructure development, is catching up with the scale of industrialization on land and with it, comes the risk of extinction for marine wildlife”, continued the specialist. A risk that the Australian fish has not escaped.

The exact cause of the species’ disappearance is unknown. But fish in this family are known to disperse and move relatively little, which makes them particularly vulnerable to changes in their environment. S. unipennis would thus have been pushed to decline notably by the loss of its habitat, destructive fishing techniques and pollution.

“This particular species was probably impacted, both via direct mortality linked to accidental catches and via habitat destruction, by the large scallop fishery which remained active in the region during the 20th century until its closed in 1967 “, notes the IUCN on the site devoted to its red list of endangered species.

Other endangered species

If S. unipennis is the first “handfish” to be declared extinct, specialists now fear that others will follow the same path. Out of the 14 species listed to date, several have become particularly rare in recent decades. Four are thus considered threatened and three are described as critically endangered.

Among them are, in particular, the “red-handed fish” (Thymichthys politus), the population of which does not count more than 100 mature individuals, and the “Ziebell hand fish” (Brachiopsilus ziebelli) which has not been observed since 2017. According to IUCN, the latter species has experienced a decline of more than 80% in its numbers over the past thirty years.

“The story of Sympterichthys unipennis should stop us and make us think long and hard about the price we are ready to pay for our seafood and what is involved in the notion of sustainable fishing,” reacted in a publication Daniel Steadman, specialist in the Fauna & Flora International organization which works for nature conservation.

“Fish like S. unipennis are the lifeblood of our ocean. We must prioritize efforts to combat the consequences of destructive fishing methods and ensure that other species do not suffer the same fate,” he concluded.

Franck Saebring

Franck Saebring is a family man first and a writer second. Born and raised in Frankfurt, Germany, only cars eclipse his love of gadgets. His very passionate about anything tech and science related.