''Carybdea marsupialis'', is a

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

ous

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

box jellyfish Box jellyfish (class Cubozoa) are cnidarian invertebrates distinguished by their box-like (i.e. cube-shaped) body. Some species of box jellyfish produce potent venom delivered by contact with their tentacles. Stings from some species, including '' ...

, in the small

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Carybdeidae ''Carybdea'' is a genus of venomous box jellyfish within the family Carybdeidae that currently consists of a total of 8 species. This genus of jellyfish are often found in warm waters around the world in waters such as the Mediterranean Sea, the ...

within the class

Cubozoa Box jellyfish (class Cubozoa) are cnidarian invertebrates distinguished by their box-like (i.e. cube-shaped) body. Some species of box jellyfish produce potent venom delivered by contact with their tentacles. Stings from some species, including '' ...

Description

''Carybdea marsupialis'' is a small transparent jellyfish with a box-shaped bell about across, at the four lower corners of which are four elongated

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s up to long. The bell has a number of small white or yellowish warts with stinging cells, and near the margin, equidistant from the tentacles, are four

rhopalia Rhopalia (singular: rhopalium) are small sensory structures of certain Scyphozoan (true jellyfish) and Cubozoan (box jellyfish) species. Description The structures typically occur in multiples of four, are bell shaped and face outward from invagi ...

(sensory structures with

ocelli A simple eye (sometimes called a pigment pit) refers to a form of eye or an optical arrangement composed of a single lens and without an elaborate retina such as occurs in most vertebrates. In this sense "simple eye" is distinct from a multi-l ...

). This species can be distinguished from other similar species by the red banding on the tentacles.

Distribution

''Carybdea marsupialis'' was once considered a widespread species found in warm oceans around the world.

Taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

reviews have shown that most of these are other species in the genus '' Carybdea'', with the true ''C. marsupialis'' essentially restricted to the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

. It is the only

in this sea. It is

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

and is present in the upper few metres of the sea.

Biology

''Carybdea marsupialis'' is a

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

and feeds on

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s and even small fish which it captures with the

nematocyst A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this ce ...

s (stinging cells) in its tentacles, often in shallow waters. It swims by making rapid contractions of the bell and can move at a speed of between per minute. Like other species in its genus it has comparatively sophisticated eyes with lenses. With their help it can detect obstacles such as posts or a ship's rudder and avoid them. It often occurs in small groups. The sting is venomous to humans but some swimmers do not notice any painful sensation. In severe cases, the symptoms can be systemic, including pain at the sting site and elsewhere,

paresthesia Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias ar ...

hyperesthesia Hyperesthesia is a condition that involves an abnormal increase in sensitivity to stimuli of the sense. Stimuli of the senses can include sound that one hears, foods that one tastes, textures that one feels, and so forth. Increased touch sensitivi ...

and skin lesions, and may take a few months to fully disappear. Although it is far less dangerous than some box jellyfish species from other parts of the world, it is considered the second-most important stinging jellyfish in the Mediterranean (''

Pelagia noctiluca ''Pelagia noctiluca'' is a jellyfish in the family Pelagiidae and the only currently recognized species in the genus ''Pelagia''. It is typically known in English as the mauve stinger, but other common names are purple-striped jelly (causing pot ...

'' being the most important). The life history of this box jellyfish is complex. The sexes are separate and sexual reproduction takes place with the emission of

gamete A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...

s into the open water. After fertilisation, a

planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which ...

larva forms which later develops into a cubopolyp with a few tentacles. This can reproduce asexually by budding, the buds soon becoming detached. At first they creep across the substrate with the tentacular region leading. During this mobile stage, pieces may become detached or the cubopolyp may split transversely; these fragments regenerate their missing parts within 72 hours. The resulting polyps then attach themselves to the substrate and grow a full complement of 24 tentacles. About a month later they become detached, the multiple tentacles are reabsorbed and the four tentacles typical of the medusa phase develop.

References

{{Taxonbar, from=Q148576 Carybdeidae Animals described in 1758 Taxa named by Carl Linnaeus