Each month, a selected blog from Lizard Island Reef Research Foundation (LIRRF) is featured at the AM. LIRRF supports scientific research & education at the AM’s Lizard Island Research Station on the Great Barrier Reef. This month, we feature: Octopus pair at Lizard Island.
On our last expedition to Jiigurru (Lizard Island), we were fortunate enough to witness a pair of Reef Octopus (Octopus cyanea) out actively hunting and copulating in the late afternoon at Watson’s Bay, with very little concern about our presence.
The larger female was actively hunting, extending her arms around whole heads of coral and using her tentacles to search for small fish or crustacean prey. She was being closely accompanied by several Coral Trout (Plectropomus leopardus) and a Goldsaddle Goatfish (Parupeneus cyclostomus), and you can see the Coral Trout actually catch a small fish at 1min:22 sec in the video!
The male Octopus was more interested in reproduction, and he had his dark, spotty courtship coloration going most of the time as he followed the female around. She seemed quite disinterested in him, however she did allow him to insert his “sexual tentacle” into her mantle cavity as she went about her feeding business, and at 1min:41 sec you can see he had to keep moving to keep his connection – she was hungry, and wasn’t waiting around for romance!
In Octopus, the “sexual tentacle” is one of the eight arms that has a specially modified tip, known as the hectocotylus, which transfers a sperm packet (spermatophore) from the male’s mantle cavity to that of the female. We can’t be sure whether mating was actually happening in this pair of Octopus or whether he was “testing the waters” as part of the courtship process, but the male did gain access to the female’s mantle on more than one occasion in the time we were watching (approximately 30 minutes) and he maintained the connections for more than a minute.
We feel very fortunate to have been allowed so close to such amazing animals, and we are stoked to be able to share this footage which shows incredible details of hunting behaviour, movement, reproduction and colour changes. Cephalopods have one of the most advanced brains of any invertebrate, and as you watch the female’s tentacles flowing over the reef surface and into tiny cracks, think about the neural processing power the animal is using to interpret all the sensory information coming in from those 8 arms and hundreds of individual suckers!!
Video taken while freediving and using only natural light on the TG6 camera systems supplied by Olympus AU & NZ.
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