If you have ever dived and found Cuttlefish during their mating rituals, you will know how weird and wonderful these creatures are. If you haven’t seen this, then book your dive trip with Scubafish here and experience this alien like extravaganza!
Generally Cuttlefish eat fish, shrimp, crabs, worms, molluscs but will also eat other Cuttlefish. They in turn are preyed upon by fish, seabirds, sharks, seals, dolphins and of course, Cuttlefish.
Cuttlefish have one of the largest brain to body size ratios and are thought of as amongst the most intelligent invertebrates. Cuttlefish cannot see colour but have highly sophisticated eyes, which are thought to give them sight even whilst in the womb. They are thought to learn their preferred prey in this way before they are even hatched.
Despite the fact Cuttlefish are colourblind, they are able to change their colour at will to match their surroundings.
Cuttlefish ratios mean there are usually 4-5 males for every female, which is a recipe for war. Males will either fight but more commonly trick each other, for the right to mate.
The most successful tactic is cross dressing! Males disguise themselves as females, by changing their colour, concealing their extra arms and even pretending to be holding an egg sack. The master of disguise can then sneak past the guarding male and mate with the female.
The successful male grabs the female with his tentacles, turns her face to face, then inserts a specialised tentacle into an opening near her mouth. He deposits sperm sacs there, fertilising the female, who he will guard until she lays their eggs only hours later. Check out this video of the dramatic event.
The female lays a batch of about 200 eggs and covers them with ink. After two to four months, they hatch out into perfectly formed little Cuttlefish with a yolk sac, to feed them until they make their first kill.
Cuttlefish populations are not well known, however, commercial fishermen in South Australia catch up to 71 tonnes during the mating season, both for human consumption and use as bait.
Because of their short life span and spawning only once in a lifetime, the threats of over-fishing are obvious. Currently there are no management restrictions in place to limit the numbers that can be taken but there is pressure to add the giant cuttlefish to the endangered species list.