Name - Cuttlefish
Scientific Name : Sepiida
Type : Aquatic Animal
Age : 1 to 2 years
Diet : Carnivore
Length : 15 cm To 50 cm.
Weight : 3 kg to 10.5 kg.
Top Speed : 40 kmph
Colour : reddish-brown
Skin Type : muscular layer of tissue called the mantle.
Lifespan : 1 to 2 years
Current Population : 247,146
Current Population Trend : increasing
Native : Mediterranean, North and Baltic seas, although populations may occur as far south as South Africa.
Main Prey : small molluscs, crabs, shrimp, fish, octopus, worms, and other cuttlefish
Habitat : shallow seas to deep depths and in cold to tropical seas
Predators : dolphins, sharks, fish, seals, seabirds, and other cuttlefish.
Lifestyle : nocturnal and diurnal
Favourite Food : shrimp
· Cuttlefish are eaten by humans as food, ink, and the cuttlebone, a calcium-rich dietary supplement for cage birds.
· Cuttlefish have sophisticated eyes, as do other cephalopods. The cephalopod eye’s organogenesis and final structure are radically different from those of vertebrates like humans. The eyes of cephalopods and vertebrates have superficial similarities that are considered to be signs of convergent evolution. The pupil of a cuttlefish is a smooth curving W-shape.
· While cuttlefish cannot see colour, they can detect polarisation in light, which improves their contrast perception. On their retinas, they have two areas of focused sensor cells, one for looking forward and the other for looking backward. Instead of reshaping the lens as humans do, the eye shifts focus by changing the direction of the entire lens with respect to the retina.
· Since it uses the copper-containing protein hemocyanin instead of the red, iron-containing protein haemoglobin contained in vertebrates’ blood, the blood of a cuttlefish is an odd shade of green-blue.
· Three separate hearts pump blood: two branchial hearts (one for each gill) pump blood to the cuttlefish’s pair of gills, and the third pumps blood throughout the rest of the body.
· Cuttlefish have ink stores, much like other marine mollusks, that they use for chemical deterrence, phagomimicry, sensory diversion, and escape when targeted. Its chemical makeup produces a dark-colored ink that is high in ammonium salts and amino acids, which may play a role in phagomimicry defences.
· The ink can be expelled as a “smoke screen” to conceal the cuttlefish’s escape, or it can be released as a pseudomorph of similar size that serves as a decoy while the cuttlefish swims away.
· Cuttlefish have eight arms and two elongated tentacles that they use to catch prey. The cuttlefish’s elongated tentacles and mantle cavity act as defensive mechanisms; when a predator approaches, it may draw water into its mantle cavity and stretch its arms to appear larger than average.
· Cuttlefish suckers cover the majority of the length of their arms and the distal part of their tentacles. Cuttlefish, like other cephalopods, have “taste-by-touch” sensitivity in their suckers, which allows them to distinguish between objects and water currents they come into contact with.
· Cuttlefish can be toxic. Venom-producing genes are believed to have descended from a single ancestor.
· Around the age of five months, cuttlefish begin to actively mate. During mating season, male cuttlefish compete for dominance and the best den. No direct contact is normally made during this challenge. Until one of the animals backs down and swims away, the animals challenge each other.
· Male cuttlefish eventually mate with females by capturing them with their tentacles, turning the female so that the two species are face to face, and inserting sperm sacs into an opening near the female’s mouth with a specialised tentacle.
· Since males may use their funnels to flush other people’s sperm out of the female’s pouch, the male guards the female before she lays the eggs, which takes a few hours. The female cuttlefish secretes ink on her eggs after laying them, giving them the appearance of grapes. The ink bag and a complex capsule of the female accessory genital glands create the egg case.
· A big rival sometimes shows up to pose a threat to the male cuttlefish. In these situations, the male tries to bully the other male first. If the competitor does not run, the male may strike it in order to drive it away. The fight and the female go to the cuttlefish who can paralyse the other first by pulling it near its mouth.
· Cephalopods can interact visually with each other using a variety of signals. Cephalopods may use four different forms of communication elements to create these signals: chromatic (skin coloration), skin texture (e.g. rough or smooth), posture, and locomotion.