Natural Marine World Tidbits

Spotted eagle ray by Tom Byrnes

The spotted eagle ray, Aetobatus narinari, is found worldwide in tropical waters.

It can live up to 25 years and grow to 10 feet across and some 20 feet long from its snout to the tip of its thin ‘tail’. A distinct spotted pattern covers its dark dorsal side, while the ventral is white.

Most rays possess a venomous spine, which is a modified tooth, as a defensive weapon. Eagle rays have five; however, they are at the base of the tail and, therefore, cannot be effectively articulated against their primary predator – the hammerhead shark.

These rays feed on all kinds of invertebrates living on – and in – the seabed, by pushing their pig-like snouts through the sand and then crushing prey, shell and all, with their powerful jaws.

They have got feeding down to a fine art, as evidenced by the inordinate amount of time left for cavorting. They are majestic and appear to be flying and soaring eagle-like throughout the water column.

Seeing a group of 19 eagle rays in tight formation slowly ‘flying’ overhead on the north wall will always be one of my most memorable diving experiences.

Tom Byrnes is the owner/operator of Cayman Marine Lab. He acquired his Coast Guard Captain’s Licence when he was a teenager and worked as a commercial fisherman in his youth. He got his first diving certificate in 1974 with the YMCA. He has worked in the local dive industry for more than 35 years and has a PhD in marine biology.

Support local journalism. Subscribe to the all-access pass for the Cayman Compass.

Subscribe now