Giant Australian Cuttlefish, also known as sepia apama, collect in shallow waters near Whyalla, South Australia. Each year between May and August thousands of Giant Cuttlefish migrate to the coastline between False Bay and Fitzgerald Bay near Whyalla for spawning. The interests the cuttlefish bring to people throughout the world are their own unique breeding behaviors, mating styles, migration, swimming abilities, diets and self-defense mechanisms. This breed of cuttlefish is one of the largest species known to man, by growing up to 60 cm long, and 5kg in weight.
There is such an enormous population of the cuttlefish that their mating behaviors can be quite competitive. During the southern winter, it is common to see vast reproduction. Even snorkelers are able to witness the changing colors and patterns of the fish when they are trying to impress their potential mate.
The cuttlefish mate in pairs and the larger the male the more likely they are to gain a female’s attention. The smaller males must make a bigger effort and when trying to mate, will change their appearance; changing their colors and their patterns will make the males look more like females. The larger male becomes distracted when the smaller male cuttlefish moves in on his female mate. As the larger male is distracted, the female gets closer to the smaller male and allows them to mate. Once the female mates with the smaller male cuttlefish, he swims away without a battle. The males are unable to reproduce while the females will not live much longer following their reproduction.
The Giant Australian Cuttlefish are amazing creatures because in each sense, they are very unique. They can change their colors and patterns and can swim according to the amount of threat they feel. They are able to ripple the fins on their side for different amounts of buoyancy for regular movement. If one of these cuttlefish feels that it is in danger, it will suck water into their own body cavity making them propel their bodies in the opposite direction (like an underwater rocket). In the event of them feeling threatened (along with the swimming), the Giant Australian Cuttlefish is able to emit a nonpoisonous could of black ink. The ink is a defense mechanism of theirs to confuse the predator long enough for them to escape. The ability to change their colors will also camouflage them by taking the appearance of rocks and sand.
In between trying to maintain their progeny and their population, they’ve got to eat. They use their two powerful tentacles that slip right beneath a crustacean of sorts and is pulled right to their strong beak. They mainly feed on crustaceans like prawns, crabs, small fish, reef fish, and tommy roughs. Along with their own diets, a much bigger predator-commonly the bottlenose dolphin-eats them. The bottlenose dolphins have been observed in South Australia and have developed a technique that removes the ink and cuttlebone from the cuttlefish, before devouring it.
Academics have been studying these animals for years, and are continuing to do so. There is a lot about this breed of cuttlefish that people are still unable to answer. For example, the people studying their behaviors do not know where they hatch their young, or how many populations make up the mass collections of this animal. The Giant Australian Cuttlefish has become a worldwide marvel, and hopefully soon, scientists, naturalists and recreational divers are able to answer some of these unknowns.
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