Sepia Officinalis

– Common Cuttlefish –

The common cuttlefish or European common cuttlefish (Sepia officinalis) is one of the largest and best-known cuttlefish species. They are a migratory species that spend the summer and spring inshore for spawning and then move to depths of 100 to 200m during autumn and winter.^[2] They grow to 49 cm in mantle length (ML) and 4 kg in weight.^[3] Animals from subtropical seas are smaller and rarely exceed 30 cm in ML.^[4]

The common cuttlefish is native to at least the Mediterranean Sea, North Sea, and Baltic Sea, although subspecies have been proposed as far south as South Africa. It lives on sand and mud seabeds and it can tolerate brackish water conditions.

Description

The body, broad and oblong, dorso-ventrally flattened , with the coloring most often marbled with white and brown on the back , paler on the ventral surface, has two main parts:
– The head, well developed, has 8 tentacles “Short” surrounding the mouth and presenting longitudinal rows of suckers, and 2 “long” tentacles at the end part in a paddle equipped with suckers, used to capture preys, usually retracted and not visible. The eyes are large and have a characteristic “W” shaped pupil.
– The rest of the body, fusiform, is surrounded along its entire length by a fin, folded over of the coat, a real swimming “skirt” undulating gracefully around the animal. Dorsally, the mantle * covers the internal calcareous shell or “cuttlefish bone”.
The most frequently encountered individuals measure 15 to 30 cm (long tentacles the same length as the body, not included). The maximum size is 45 cm.
Males are distinguished from females by the stripe of the most lateral tentacles and the anterior part of the mantle.

Taxonomy

It is unknown where the type specimen of S. officinalis was collected, as the location is given simply as “Oceano”. It is deposited in the Linnean Society of London.^[16]

Sepia officinalis jurujubai Oliveira, 1940, originally described as a subspecies of the common cuttlefish, is a junior synonym of Sepioteuthis sepioidea.^[17]

Biotope

From the surface to about 200 m deep.
The cuttlefish is occasionally observed on the rock, but it will most often be found on soft bottoms, sand or gravel, in seagrass beds or among large algae. Partial burial in the sediment is frequent.

Similar Species

Two species of reduced size much rarer but with identical distribution:
-Seiche d’Orbigny or pink cuttlefish ( Sepia orbignyana de Férussac, 1826) about 10 cm long, dorsal color predominantly pink or orange, end of the body pointed.
-Elegant seiche ( Sepia elegans de Blainville, 1827) 8 cm maximum, very slender general appearance, a pink dorsal spot.

Predators

Cuttlefish only have a lifespan of 1–2 years (captive and wild) and have many predators including sharks, dolphins, seals, fish, and cephalopods which includes other cuttlefish.^[5] They have many defensive mechanisms to help protect them from predators including a siphon which they can use to shoot water out of to propel them away from danger, ink which can distract and disorient a predator as the cuttlefish escapes, and their camouflage abilities which can help them avoid predators altogether.^[6]

A 2008 study on S. officinalis^[7] revealed that cuttlefish embryos, if visually exposed to a certain species of prey (e.g. crabs), will hunt primarily for that prey in later life. S. officinalis usually prefer shrimp to crabs, but when the embryos were exposed to crabs and the embryos had hatched, the young cuttlefish switched preferences and proceeded to hunt the crabs more often than the shrimp.^[8]

Alimentation

The cuttlefish is an active and voracious predator with a formidable hunting technique. On the lookout, camouflaged by its homochromy *, it projects its two long tentacles towards its victim. Once captured, the prey is brought to the mouth and held by the short tentacles, then after injection of toxic saliva secreted into the two venom glands, it is cut by the horny jaws forming an inverted “parrot beak”.
Its preys are fish, molluscs and crustaceans (fry, shrimps, crabs, gastropods, other cephalopods). Juveniles are not afraid to prey on animals larger than themselves.
The predators of cuttlefish are big fish… and other cuttlefish. Cases of cannibalism seem frequent.

During the day, most cuttlefish can be found buried below the substrate and fairly inactive. At night however, they are actively searching for prey and can ambush their prey from under the substrate. Cuttlefish are carnivorous and eat a variety of organisms including crustaceans (crabs and shrimp), small fish, molluscs (clams and snails), and sometimes other cuttlefish which is more commonly seen when the abundance of other prey is low.^[5]

Anatomy

The common cuttlefish is one of the largest species of cuttlefish with their mantles (does not include their head and arms) reaching upwards of 45 cm. The mantle houses the reproductive and digestive tracts of the cuttlefish and is also home to an internal shell called the cuttlebone.^[2] The common cuttlefish has two highly developed eyes, eight arms which are located around the mouth and are used to hold and move prey, two tentacles which are used to quickly capture prey, and a radula which is used to tear and rip apart any prey they have captured.^[5] Cuttlefish are well known for their unmatched camouflaging abilities which are possible due to light scattering leucophores, pigmented chromatophore organs, and structurally reflecting iridophores all located in their skin.^[9] These specialized characteristics give them the ability to not only change their colour, but also change the texture appearance of their skin and all of this is done despite them being colour-blind. Their camouflaging abilities are categorized into four main types including mottle, stipple, uniform, and disruptive.^[10] These complex camouflage abilities are not just present in adult cuttlefish, but cuttlefish juveniles also have these complicated characteristics, which allows them to be able to camouflage from a young age.^[11]

Reproduction

In the spring the adults migrate to the surface waters, close to the coast, where courtship displays and matings take place.
Fertilization is internal. The male deposits in the palleal cavity * of the female his spermatophores * (elongated bulbs containing the spermatozoa) by introducing there his copulatory tentacle or “hectocotyle *”. Fertilization of the eggs takes place an hour and a half after copulation. During this time, the male watches the female closely, in a sort of post-coital display, to prevent another male from mating and replacing his spermatophores with his own. (photo n ° 6)
The spawning called “sea grape” is characteristic: black eggs ending in a point, assembled in clusters.
Mature eggs lose their black coloring and young cuttlefish measuring around 12 to 15 mm can be seen. As soon as they hatch, they are able to capture prey and already have a whole repertoire of colorations.
The growth of young cuttlefish is particularly rapid. About 10 mm per week, it is visible from one dive to another. The cuttlefish born in early June reach 15 cm at the end of August.
The adults die after the breeding season.

 Cuttlefish reach sexual maturity between 14 and 18 months of age. During breeding season, which occurs during spring and summer in shallow waters, male cuttlefish will display a black and white zebra pattern on their mantle to attract females and females will display a uniform grey colour to indicate they are ready to mate. Cuttlefish are internal fertilizers and the number of fertilized eggs can range from 100 to 1000. After the eggs are fertilized, they will remain in the oviduct of the female for anywhere between 30 and 90 days before they are laid.^[2] The eggs attach to seaweed, shells, or other substrates to prevent them from drifting away and have ink deposits on them to aid in camouflage.^[12]

Associated Life

Cuttlefish are usually isolated. They regroup at the time of the courtship displays where we can see several males courting the same female, or wait their turn.

Various Life

Behavior : The cuttlefish is an animal with a high psyche showing great behavioral richness.
Homochromy : The cuttlefish constantly adapts the coloring and texture of its skin, either to go unnoticed by blending into the environment, or on the contrary to become very showy. Colored cells, the chromatophores *, can spread over the surface: dark color, or retract: light color, almost instantly. The skin may also change appearance: smooth or spiky with soft growths.
Emotions or excitations are accompanied, on the head and the back, by waves of colored signals. These modifications occur to cause fear and confusion in prey or predators, or to communicate with other cuttlefish, in particular during the breeding season.
Locomotion : The cuttlefish usually moves slowly thanks to the undulations of the fin lining the body. It is also capable of extremely rapid movements by suddenly expelling through the muscular siphon * the water contained in the palleal cavity * (ventral cavity where the gills bathe and where the anus and genital orifice open).
When it feels threatened, the cuttlefish, like other cephalopods, can hide its flight by expelling a cloud of black ink that deceives its attacker. The latter stops in his attack on the ink cloud, while the cuttlefish is already a meter away. “Take the prey for the shade”.

Uses

Sepia officinalis is a species that is commonly fished in the Mediterranean, including countries like Greece and Spain. Although it is fished extensively and wild stocks in some regions are close to being over-exploited, population numbers are not declining so the species is of Least Concern on the list of threatened species.^[12] Cuttlefish have many uses which makes them a popular catch. Their cuttlebones are commonly sold in the pet bird industry because they provide a good source of calcium, help keep a bird’s beak trimmed, improve jaw strength, and provide entertainment for the bird.^[13]Sepia officinalis is also growing in popularity as a foodstuff because it has a similar taste to octopus and squid and is a good source of healthy proteins and lipids.^[14]Cephalopod ink is believed to have many beneficial health effects including anti-inflammatory and anti-oxidant activity, antimicrobial and potential anticancer properties, and anti-hypertensive and anti-retroviral activity.^[15] Other uses for cephalopod ink include writing, drawing, and painting uses along with potential cosmetic uses. Similar to cuttlefish meat, the ink is also commonly used in the food industry for both its flavour and as a food dye.^[15]   As seen when dead, the long prehensile tentacles being withdrawn from the pouches at the side of the head, in which they are carried during life when not actually in use. a, neck; b, lateral fin of the mantle; c, the eight shorter arms; d, the two long prehensile tentacles; e, the eyes

Further Information

Cuttlefish ink or ” sepia “: This ink, called sepia, was formerly used in painting (drawings, washes, watercolors) and in photography.
The cuttlefish bone or sepion: It is a familiar object, often encountered, rejected by the sea, on our Atlantic beaches. This calcareous inner shell has a honeycomb structure. A complex mechanism allows the animal to vary the quantities of water and gas therein and thus precisely adjust its buoyancy.
In the 18th century, it is found in the pharmacopoeia: “Dry bone (…) is one of the absorbent drugs (…) astringents & remedies suitable for tightening the belly. (…) {It} is more frequently used for external uses, as a detergent & desiccant, both to erase stains from the face and to whiten teeth. »
It serves as a calcium supply for aviary birds.
It was used in jewelry making to make jewelry casts. Its fine and tender structure makes it possible to take the imprint of the jewel to be reproduced, and it resists the heat of molten gold.
Gastronomy : The muscles of the mantle or “cuttlefish white” and the tentacles are eaten and appreciated. A la plancha, in American sauce, with rice ….
Cuttlefish fishingis intense near the coast at the time of its reproduction, both adults in spring and juveniles (cassons) in late summer and autumn. Fishing is the waiting net (trammel) and especially ” jigging “. It is a colored plastic lure, vaguely imitating a fish, with two rows of hooks that are waved near the bottom.
It is to be feared that “the resource” will run out, when we see the quantities fished by both professionals and more or less amateur boaters.