Ox-eye oreo a cony deep-sea creature


Bec Crew


Bec Crew

Bec Crew is a Sydney-based science communicator with a love for weird and wonderful animals. From strange behaviours and special adaptations to newly discovered species and the researchers who find them, her topics celebrate how alien yet relatable so many of the creatures that live amongst us can be.
By Bec Crew 4 June 2015
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Deep-sea creatures often have unusual features and the ox-eye oreo is no exception

IF YOU SUDDENLY can’t stop thinking about little round chocolate biscuits when you look at this creature, you’re not alone – I’m right there with you. Eespite that rather disc-like body, which looks like it’s been drizzled with a thick coating of burnt caramel, the curious little ox-eyed oreo (Oreosoma atlanticum) was not named after a dessert.

Rather, Oreosoma actually means ‘mountain body’, because if you turn one upside down, you’ll get a perfect little snow-capped mountain range.

Found in the temperate, tropical, and sub-tropical waters of the south-eastern Atlantic and western Indian Oceans, most commonly off the coast of Australia and New Zealand, the 21cm-long deep-sea fish is typically found at least 500m down, and can even sink to depths of more than 1.5km.

Its enormous doe eyes help it to see through the murky depths, and indeed they’re so big that each of their diameters make up 50 to 60 percent of the total head length.

The ox-eyed oreo will hatch as a blackish-violet-coloured fish, its cones taking on a silver-green hue, before everything turns a light brown and cream colour in adulthood.

The strange cones of the oreo fish

As the only member of the Oreosoma genus, its juveniles have the largest and most distinct spines along its undersides of all known oreo species, and it will lose these as it matures. They come in a set of 10, split into two parallel rows of five. No other family of fish has cones quite like these.

To see the odd body of the ox-eyed oreo from an entirely different perspective, check out the X-ray below, by Sandra Raredon from the Department of Vertebrate Zoology at the Smithsonian National Museum of Natural History in the US.

As part of a recent exhibition, X-ray Vision: Fish Inside Out, Raredon x-rayed 40 different marine species, including several fish, stingrays, eels, and seahorses – “anything with a backbone,” she says