Species Over 120
Similar to octopuses and squid, cuttlefish are marine mollusks, despite their name. These intriguing creatures are tiny to mid-sized cephalopods that are available in various waters around the globe.
Cuttlefish possess long bodies and big heads with enormous eyes and mouths that resemble beaks. They have eight arms, like octopuses, as well as two extra extended tentacles for catching prey. Two pouches may be used to store these tentacles. Suction discs on the arms and tentacles may be employed to help them both manoeuvre and immobilise prey. A solitary muscular fin that wraps around the body of the cuttlefish like a skirt is capable of propelling it in every direction.
These mollusks may be available all throughout the world, from balmy tropical waters to the icy depths of the deep ocean. Cuttlefish may be found around the shores of East and South Asia, sections of Western Europe and the Mediterranean, as well as all of Africa and Australia’s coasts. In the Americas, they have never been discovered.
There have been 120 species in total, with sizes ranging from the tiny flamboyant cuttlefish (Metasepia pfefferi) with a length of 3.1 inches (8 centimetres) to the biggest species, the Australian giant cuttlefish (Sepia apama). This giant cuttlefish may grow to be 20 inches (50 cm) long without tentacles and weigh more than 23 pounds (10.5 kg). Cuttlefish are carnivores that devour mostly crabs and shrimp, along with a range of fish species.
The brain-to-body size ratio of these mollusks is among the greatest of all invertebrates. These mollusks appear very clever. This implies they can remember and learn. Despite being colour-blind, they have excellent vision and can quickly alter their form, colour, and motions to communicate and disguise.
Sharks, bigger fish, and even other cuttlefish are the most frequent predators of cuttlefish. They are also hunted for food by humans. Similar to octopuses, cuttlefish may use ink to evade attackers. Such ink is kept in an ink bag when it is required. At that moment, the cuttlefish will discharge it into the water to produce a distraction, allowing them to flee. This distraction may take any one of two forms: the ink is discharged, and a screen is created, allowing the cuttlefish to run swiftly. The ink is expelled in mucus-wrapped bubbles that seem to be the same size and shape as the cuttlefish in the second, confusing the predator and allowing it to escape.
Notable Cuttlefish Species
One of the most recognisable cuttlefish species is the common cuttlefish, also known as the European common cuttlefish (Sepia officinalis). They are a huge species that migrates between inshore locations throughout the winter and summer seasons, when they reproduce, and greater depths over the winter.
Flamboyant cuttlefish (Metasepia pfefferi) may be identified in the Indo-Pacific seas along the coast of northern Australia, as well as around a number of islands in the Philippines, Indonesia, and Malaysia. This cuttlefish contains a remarkable defence system: its meat carries a unique venom that makes it very poisonous to consume.
The Pacific bobtail squid (Sepioloidea pacifica) is a species of cuttlefish that inhabits the southwestern Pacific Ocean. It may be located off the east and west coasts of New Zealand.
Koch’s bottle tail squid, also known as the tropical bottle tail squid (Sepiadarium kochi), is a cuttlefish that may be found from India to Japan in the Indo-West Pacific. The Indo-Malayan area is also home to this species. The greatest length of this edible cuttlefish’s mantle is 3 centimetres.
Fun Facts about the Cuttlefish!
Cuttlefish are strange and amazing creatures that are fascinating to see. These organisms are an excellent representation of numerous amazing biological ideas, from comprising 3 hearts to possessing the ability to rapidly change colour. Let’s investigate further!
Cuttlefish Have Three Hearts
Similar to octopuses, cuttlefish possess three hearts. One heart pumps blood with oxygen throughout the body, while the remaining two—one for each pair of huge gills—pump blood to them.
Its blood is also blue-green due to the presence of haemocyanin. There is a copper-containing protein in their blood. Haemoglobin Is used to carry oxygen, similar to the red, iron-containing protein haemoglobin present in humans and many other organisms.
Chameleons of the Sea
Cuttlefish are referred to as the “sea chameleons” because of their capacity to alter colour. Disruptive arrangements disrupt the contours of certain species. While others change colour to blend in with their environment. These mollusks feature chromatophores, which are specialised skin cells that may expand and contract to alter the colour of their skin. The cells may be used individually or in combination to create a wide range of colours and patterns. They could change their look in seconds and also use dark camouflage!
Cuttlefish utilise their color-changing ability not just to disguise themselves, but also to attract partners during the mating season. The males will use their color-changing powers to attract ladies as well as to fend off rival males. Male cuttlefish use their color-changing powers to fool other men into believing they are females, allowing them to slip in and mate with their female without being discovered. Sneaker-males are the name given to this cuttlefish.
Cuttlefish have an internal long bone called a cuttlebone, which helps them retain buoyancy. The cuttlebone is not really a bone, but rather a calcium carbonate shell composed of aragonite, which has a lattice-like structure. Based on their position within the water column, several chambers inside this shell may be filled with either gas or water. If the cuttlefish wants to sink, it must lose buoyancy. It will fill the chambers in the cuttlebone with more water than gas. When the cuttlefish wants to ascend, though, more gas is added than water.
Cuttlebones, which are high in calcium, are marketed at pet shops and offer a dietary supplement for a variety of species, including birds.
Cuttlefish have strange and fantastic eyes that allow them to find appropriate food and start hunting immediately once they hatch. The eyes of these mollusks are big, dark red, and have a prominent w-shaped pupil. Cuttlefish are born with extraordinarily well-developed eyes.
Their eyes are designed to see through the dispersed light seen in the water, allowing them to seek food. Cuttlefish are colour blind, yet they can detect polarised light contrasts. Despite their colour blindness, these mollusks have excellent vision and can swiftly shift their whole lenses to concentrate on things. They employ their capacity to concentrate quickly to aid in colour differentiation. Because the optic nerve lies behind the retina, they have no blind spots.
Cuttlefish lack colour vision, yet they can detect polarisation disparities in light. These mollusks will adjust the whole lens in their eyes to acquire an exact view in order to concentrate on objects. The cuttlefish may use its vision to find appropriate prey before it hatches, even before it is born.