The Sepia latimanus, the broad club cuttlefish, at the Steinhart Aquarium in the California Academy of Sciences are six months old and are really starting to show the behaviors of adults. Sometimes known as the Giant Cuttlefish, S. latimanus is reported to reach 50cm in length and weigh up to 10kg (though I have never seen one in the wild that size). With a lifespan of 1-2 years and such large size, it makes sense that a hatchling about 1 cm long in February could be almost 18cm long in July. Like all cephalopods, these guys are eating machines, able to completely eat a silverside in under 2 minutes – with no leftovers at all. They are being fed at least 3 times a day with different feeds including live crabs, live bait shrimp, thawed prawns and thawed silversides. With the fast growth, some issues have started to appear including minor ‘butt burn’, damage to the tip of the mantle caused by the animal jetting into the sides quickly (a big animal is a strong animal!) and inking events due to adolescent competition blackening the tank water. To help alleviate these issues, the population has been split into two groups, 2 animals on display and 4 animals in holding. The other adult behaviors are way more exciting.
In the video above (oh, blue lights and video – why do you hate each other) you can see a lot of color pulsing on the skin of the cuttles as they hunt for food. It is thought that this striking pattern and color show somehow helps in hunting, perhaps confusing prey into motionlessness. However, unlike wild adults, the color patterns have not yet reached down the two wide arms that are often stretched out horizontally during hunting – which incidentally help give this cuttle their ‘broadclub’ common name. The patterns also seem to originate at the back of the mantle, while wild adults seem to pulse more on the head and arms (as shown in the video from NOVA’s ‘Kings of Camouflage’ linked below). The other interesting behavior in the video above is the ‘banding-of-the-eyes-darkening-of-two-arm-tips-while-gesticulating-madly’ behavior (rolls off the tongue eh?), which only seems to occur when the animals are hunting silversides, perhaps this is another distraction technique.
As you can tell, I am over the moon with excitement over these behaviors, and even more excited that they are happening with the animals on display. If you are any kind of ceph-head and are in the SF area, I urge you to get down to the academy and take a look as these amazing animals while they are on display.