Each cuttlefish has a pair of undulating fins that span the length of their body and help the creature to swim and maneuver; for any quick movements, it propels itself by shooting water from its gut. In the middle of eight forward-reaching tentacles, there is a small beak, which cuttlefish use to break open the shells of mollusks, crabs, and other crustaceans. Cuttlefish also have two longer tentacles, with a single suction cup at each tip.
They use these elongated arms to grab their prey. Cuttlefish have a short life span, but they grow quickly. They may only live one or two years, but some species can grow up to about 23 lbs Since they have such fast growth rates, cuttlefish are careful not to expend too much energy and usually spend about 95 percent of their time resting.
Cuttlefish also have an internal structure called a cuttlebone that allows them to conserve energy by helping to keep them buoyant. The scariest part about cuttlefish, however, is the actual manner in which they get ahold of their prey.
By utilizing their color changing abilities like their squid and octopus cousins, cuttlefish are able to hide in plain sight, lying in wait for whatever meal dares to venture near them. When something does come past that looks like an easy target, cuttlefish lash out with their two tentacles at lightning speed, grab their prey with the dozens of suckers, and then slowly bring the food in towards their beaks with their remaining arms.
The key piece of anatomy for cuttlefish and their ability to eat is their feeding tentacles. These two long arms are much longer than the rest of their tentacles and let the cuttlefish lash out at their victims and trap them with ease. They were sent by overnight courier and were lightly sedated to help them with the transportation. Later the next day they turned up at my door in very good condition, especially considering that they had traveled the length of the United Kingdom in just one night.
Thankfully I had also been supplied with a lot of good practical information, and most of it still holds true today. One helpful fact I had learned was that the acclimation of cephalopods is of paramount importance. It has to be done slowly and with water that has parameters as close to true sea water as possible. Likewise the pH must always be above 8. The young cuttlefish were about 12 mm long and were put into a mature aquarium measuring 36 x 15 x 15 inches with water parameters of pH 8.
I took more than an hour using a dripping airline to gradually add the new aquarium water. Most importantly, Sepia officinalis is not a tropical species, so the tank was unheated and temperature sat in the mid 60s. The aquascaping was kept very basic and consisted of a one-inch-deep layer of fine, well-washed sand.
An internal filter was used for filtration, there were no lights above the tank at this stage, and hiding places consisted of a few halved clay plant pots. The cuttlefish were gently scooped out of their bag with a whisky glass and carefully poured into the tank. One of the babies decided to demonstrate its ability to squirt ink while being moved, and it was amazing to see.
At this age the young cuttlefish eject a blob of ink that holds its shape for a few moments, while at the same instant they make a sudden dive for the substrate and bury into the sand. The theory is that the assumed predator gets momentarily confused by the blob and bites it while the young cuttle escapes.
These small pseudomorphs can be netted out with a fine net. Feeding cuttlefish is anything but easy. The main diet of cuttlefish in the wild is crustaceans, and to a lesser extent fish. I decided that Crangon crangon, a locally caught shrimp found on sandy beaches near my home, would be perfect. A 15 mm cuttlefish will easily go through three or four to mm shrimps per day. Let me also steer you away from using live feeder fish. As is the case with a lot of other invertebrates, copper is deadly to cephalopods.
Watching them hunt their food is truly amazing. A cuttlefish can change color in the blink of an eye and even extend flaps of skin to change its overall texture, too.
They will sneak up on a shrimp from behind, and once it is in striking distance the cuttlefish shoots out a pair of long feeding tentacles and pulls in the meal. There is no escape. In time the cuttlefish grew, and within a couple of months I moved them into their larger quarters. The filtration was a large homemade trickle tower and an equally large protein skimmer. The tank was actually set up as a reef tank with hardy corals and no other non-sessile species, which would be seen as a snack.
The only other inhabitants were the cleanup crew, which consisted of a few brittle stars, turbo snails, and some red leg hermits—all of which were largely ignored. Amphipods and bristleworms appeared from the live rock, and although the amphipods were eaten at first, once the cuttlefish grew they were ignored and their population exploded. Luckily by this stage I had managed to wean the cuttlefish onto non-living foods, and getting suitably sized raw frozen shrimps from the local seafood shop was a lot easier than catching shrimp every couple of weeks and keeping them alive.
As far as crabs are concerned, I would go to the rock pools and collect enough shore crabs for a month or so.
Then I would take them home and freeze them myself. Sepia officinalis can get to a size in the wild approaching 18 inches in total length. After about six months my seven were ranging from 3 to 6 inches, and I started to make out some possible differences between the sexes, namely the males being larger and more territorial.
It was around this time that I had a casualty. Fighting during feeding times was fairly frequent and normally happened when two cuttlefish would fight over the same item of food. However, apart from a few sucker marks the fights looked worse than they were. There was one exception.
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