First glimpse of deep sea dwellers in underwater mountain range

These seamounts have never previously been filmed and information about them is still scarce. The filming was carried out using an underwater robot (ROV), at depths of up to 600m, during the Oceana Ranger expedition around the Canary islands Photograph: Carlos Minguell/OCEANA

The remote vehicle operators will do a series of checks to prevent failures and malfunctioning. A failure at depths of over 500m could hamper the vessel with a snag on the steep underwater walls Photograph: Carlos Suarez/OCEANA

A field of glass sponges (Asconema setubalense) at 376m depth is viewed onboard the research vessel. These sponges, which can reach up to 1m in height, are usually found off the coast of Portugal. Recently, this species has also been identified in El Cachucho, a seamount off the coast of Asturias. This is the first time this sponge has been identified in waters of the Canary islands Photograph: Carlos Miguell/OCEANA

Rosy dory (Cyttopsis rosea). The Sahara seamounts are located between 140 and 190 miles south-east of the island of El Hierro. Many of them rise up from seabeds almost 4,000m deep, and some have summits just 200m from the ocean’s surface Photograph: OCEANA

An unidentified sponge. Echo is a seamount that is also known as Endeavour Bank, whose summit is formed of a large plateau measuring 350km sq, located between 230-350m depth, with its sides dropping up to 3,800m into the deep seas Photograph: ROV/OCEANA

Shortnose greeneye (Chlorophthalmus agassizi). The first images Oceana obtained of these seamounts show rocky and sandy seabeds, volcanic in origin, including an abundance of caves, overhangs and cracks harbouring a variety of fauna Photograph: ROV/OCEANA

Bluntnose sixgill shark (Hexanchus griseus). The area is rich in sixgill sharks, a deep-sea shark that can reach almost 5m in length and weigh more than 500kg Photograph: ROV/OCEANA

Unidentified gorgonian Photograph: ROV/OCEANA

The Oceana marine scientist Ana de la Torriente studying the charts of the area to be surveyed Photograph: Carlos Suarez/OCEANA

After filming these hidden ecosystems, the Ocean Ranger research catamaran returned to the Canary islands to continue the sampling work being carried out of the archipelago’s seabeds in collaboration with the Spanish Biodiversity Foundation Photograph: Carlos Minguell/OCEANA