Marine scientists have discovered more than 110 new fish and invertebrate species in the Coral Sea – a figure they believe could exceed 200 as more are identified.

The species were found in waters between 200 metres and 3km deep in the Coral Sea marine park, Australia’s largest marine protected area, which spans nearly 1m sq km to the east of the Great Barrier Reef.

The new-to-science species – including brittlestars, crabs, sea anemones and sponges – were collected during a 35-day voyage on the CSIRO’s Investigator research vessel, which set sail from Brisbane last October. It travelled as far as Mellish Reef, about 1,000km off the Queensland coast.

Dr Will White, a shark expert and the CSIRO voyage chief scientist, said the expedition set out to learn more about the area’s deepwater biodiversity, for which there was “very limited data”.

Specimens collected on board were subsequently identified during what White believes were “likely the largest taxonomic workshops of marine animals ever undertaken in Australia”.

White himself identified four new species – a new skate, ray, deepwater catshark and chimaera – also known as a ghost shark.

The ray species, found on the Kenn Plateau about halfway between Australia and New Caledonia was a type of stingaree, in the genus Urolophus. The animals were like stingrays, White said. “They’ve got a relatively long tail but then they’ve got a caudal fin at the end.”

The new deepwater catshark (genus Apristurus) was a tropical species, White said. “They’re very dark-bodied, they’re almost flabby – truly deepwater things, very slow moving, [with] lots of little teeth.”

The skate, in the genus Dipturus, was light grey, with “quite a long snout and … a hard bit of cartilage in the middle of it”, White said. “It has a fleshy bit forming a long triangular snout area; they have some thorns around the eyes.”

Another discovery was a new chimaera – also known as a ghost shark or rat fish – a type of animal related to sharks and rays, which have cartilaginous rather than bony skeletons. The animals have a “rat-like tail, quite a plump nose, and a big spine above the dorsal fin”.

Dr Claire Rowe, the marine invertebrates collection manager at the Australian Museum, said invertebrate specialists on board the Investigator photographed and took tissue samples of the newly collected animals.

She said many invertebrates, including jellyfish, were cryptic – difficult to identify based on physical characteristics alone. “There does look like there’s some new species of anemones, which is quite exciting,” she said.

Scientists were conducting further genetic testing from the tissue samples to confirm what collected specimens were new to science.

Such marine expeditions were important, Rowe said, because “so little is known about the deep sea”.

“It’s such an unexplored area, and with so many threats to our ocean, such as overfishing and climate change and deep sea mining, we need to understand what’s out there before it’s lost.”

The Coral Sea is almost half a degree warmer than it was 30 or 40 years ago, climate scientists say. The sea surface temperatures there over both the last summer and calendar year have been the hottest on record.

Samples from the voyage have been shared around the country, held in collections including at the CSIRO, the Australian Museum and state museums.