goby fish
Coryphopterus curasub – the newly discovered goby species – lives some 50m deeper than its relatives Carole Baldwin and Ross Robertson, Smithsonian Institution

A new type of goby fish has been discovered which dwells deeper than its relatives and is a different colour and size.

The newly discovered fish lives some 50m deeper than its relatives – which typically reside about 20m below the surface – and has been found in the Caribbean near the island of Curaçao. It is around 3.3cm long – most goby fish are less than 10cm – and white with orange spots.

It was discovered by Drs Carole Baldwin and Ross Roberson of the Smithsonian Institution in Washington DC as part of its Deep Reef Observation Project (DROP). They have dubbed it Coryphopterus curasub after the Curasub submersible which was used to explore the deep reefs of the Caribbean, according to the study published in ZooKeys.

New depths are open to exploration around the area thanks to the availability of privately owned submersible – a small submarine – says Baldwin.

She said: "This is the fourth new deep-reef fish species described in two years from Curasub diving off Curaçao. Many more new deep-reef fish species have already been discovered and await description, and even more await discovery.

"Deep reefs are diverse ecosystems in tropical seas that science has largely missed, too deep to access using scuba gear and too shallow to be of much interest to deep-diving submersibles capable of descending thousands of metres. How incomplete is our picture of tropical reef biodiversity if so little attention has been devoted to depths just below those home to shallow coral reefs? We don't know.

"Imagine conducting a census of people living in Washington DC, but you only survey those inhabiting ground-level housing structures. If you don't know about the people living on second, third, fourth, etc, floors in apartment buildings and condominiums in a city packed with them, you're not getting a very complete picture of who lives here. Scientists' ignorance of the biodiversity inhabiting depths within a couple hundred meters of shallow coral reefs is similar.

"We know that in temperate coastal areas, some fish species are being found at higher latitudes than previously recorded," Baldwin said, "presumably a response to warming surface waters."