Sunfish are the largest bony fish in the world, reaching lengths of ten feet and weighing 5500lbs! But not much is known about the larval stages and trying to identify the five species that visit Australian waters has been difficult until now.
“Super-excitingly we have just genetically identified the first ever larva of the ‘giant sunfish’ (Mola alexandrini) – the famous sunfish divers can swim with off Bali.” Said Ocean Sunfish Research on their Facebook page.
“These larvae are exceedingly cute but super-hard to come by so huge thank you to everyone in Australia and New Zealand who helped make this possible.”
Sunfish are well known for their huge size, strange shape and the way they are often seen to “bask” on the surface of the Ocean. They propel themselves forward using their dorsal and anal fins and steer from the back, not with a tail but a rudder.
Their mouths are fused together and they dine on predatory Hydrozoans (a type of Jellyfish,) which gather at the surface. Despite being mainly surface dwellers they can dive to depths to 2700 feet and are found in temperate and tropical waters around the world.
300 million eggs!
A single sunfish can produce 300 million eggs in a single spawning. That’s the same as 300,000 Sockeye salmon! And trying to tell which larvae is which has been impossible until the Australian Museum team recently cutting edge DNA analysis to identify them.
Thanks to the Ocean Sunfish Research team, who gave us written permission to use their photos. For more information on Sunfish and their research, visit the Australian Museum and Ocean Sunfish Research pages.