The Differences Between Squid And Cuttlefish
Although these mollusks are morphologically similar, there are some differences between squid and cuttlefish.
Below, we will give you some information about these two animals to help you get to know them and recognize them more easily. Here are the differences between squid and cuttlefish.
The most important characteristics of the squid
The squid is a cephalopod mollusk that is part of the order of the Teuthida. This includes two suborders, Oegopsina and Myopsina, which encompass the different species of squid known today.
The Oegopsina subgroup includes several families with a large variety of species, including the famous giant squid.
On the other hand, only one family is classified in the suborder Myopsina , called Loliginidae.
These are carnivorous marine animals and invertebrates related to cuttlefish, polyps and nautils.
Anatomically, they are characterized by the presence of two main tentacles and eight arms.
Characteristics of the squid
The squid’s tentacles show well-developed musculature and are equipped with powerful suckers. Some species, such as giant squid, are able to regenerate their tentacles, in case they lose them or purposely uproot them to escape predators.
Another typical feature of the squid is its particular circulatory system, consisting of two gill hearts and a systemic heart.
This mollusk has two gills, through which it breathes normally in aquatic ecosystems.
The squid and its ability to disguise itself
Squid have special skin cells known as chromatophores that contain pigments within them and are capable of reflecting light.
In addition to giving their skin color, these cells allow these animals to change shades easily to camouflage themselves in the environment.
This strategy combines with the ability to eject their ink to confuse and scare predators away.
The high concentration of chromatophores also explains why the squid exhibit bright colors.
In fact, a great variety of colors can be observed between the different species.
General aspects of cuttlefish
The cuttlefish is also a cephalopod mollusc, but it belongs to the order of the Sepiids. More than 100 species of cuttlefish are found in this.
It is medium in size and usually reaches 40 cm in length in adulthood. Its body has an oval and slightly flat shape, surrounded by two fins that form a kind of skin crest.
One of the features that stands out is the presence of 10 irregular tentacles that are located around the mouth. Of these 5 pairs, four are shorter and have two rows of suction cups each.
The longest pair are retractable and are three times larger than the other tentacles. At the ends it has a kind of shovel formed by various irregular suckers.
These long tentacles are used not only to capture prey, but are also essential for the reproduction of cuttlefish.
Similarities and differences between squid and cuttlefish
In getting to know these aquatic animals a little better, we can say that there are similarities and differences between the two.
These species do not look alike by chance, but are genetically related, and this generates anatomical and physiological similarities.
Despite this, they have a different body. The cuttlefish has it oval and slightly flattened, while the squid has it more elongated and cylindrical.
Furthermore, the cuttlefish can reach 40 cm in length, while the squid at least 60 cm. Some species of giant squid can exceed 15 meters.
The squid has two tentacles and 8 arms with suckers. Instead the cuttlefish has 11 concentrated around the mouth, and they are considerably less than those of the squid.
Another difference lies in the size of their inner shell. The squid has a thin, cartilaginous, flat and transparent structure known as a feather.
The internal shell of the cuttlefish, on the other hand, is spoon-shaped and its composition is calcareous, giving it a white color. This is another trait that differentiates it from squid.