:''The

tortrix moth The Tortricidae are a family of moths, commonly known as tortrix moths or leafroller moths, in the order Lepidoptera. This large family has over 11,000 species described, and is the sole member of the superfamily Tortricoidea, although the genus ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Cerata'' is considered a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linn ...

of ''

Cydia Cydia is a graphical user interface of APT (Advanced Package Tool) for iOS. It enables a user to find and install software not authorized by Apple on jailbroken iPhones, iPads and iPod Touch devices. It also refers to digital distribution ...

Cerata, singular ceras, are anatomical structures found externally in

nudibranch Nudibranchs () are a group of soft-bodied marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, ...

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary tim ...

s, especially in aeolid nudibranchs,

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

opisthobranch Opisthobranchs () is now an informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping. Euopi ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s in the

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

Aeolidida The Aeolidida is a taxonomic clade of sea slugs, specifically aeolid nudibranchs, marine gastropod molluscs in the clade Cladobranchia. They are distinguished from other nudibranchs by their possession of cerata containing cnidosacs. Ta ...

. The word ceras comes from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word "κέρας", meaning "horn", a reference to the shape of these structures. Cerata are

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

and lateral outgrowths on the upper surfaces of the body of these nudibranchs.

Function

Cerata greatly extend the surface area of nudibranchs and aid in

respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellul ...

, the process of gas exchange for metabolic use. Cerata are also used, in some cases, for attack and defense. In many aeolid nudibranchs, the digestive system extends into the cerata. These nudibranchs eat stinging celled animals (

Cnidaria Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that ...

ns) such as

anemone ''Anemone'' () is a genus of flowering plants in the buttercup family Ranunculaceae. Plants of the genus are commonly called windflowers. They are native to the temperate and subtropical regions of all continents except Australia, New Zealand an ...

s, hydroids and

sea fan Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different ...

s or Portuguese men o' war. The stinging cells or

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 are passed unharmed through the digestive system to

cnidosac A cnidosac is an anatomical feature that is found in the group of sea slugs known as aeolid nudibranchs, a clade of marine opisthobranch gastropod molluscs. A cnidosac contains cnidocytes, stinging cells that are also known as cnidoblasts or ne ...

s at the tips of the cerata. Here the nematocysts mature and are then used by the nudibranch for its own defense. In some nudibranchs, cerata are used as decoy tactics. Typically, these cerata are not armed with nematocysts, but when attacked, the nudibranch will autotomise or drop one or more of its cerata. The dropped cerata produce a sticky secretion and wriggle energetically for some time after being cast off, presumably causing a distraction and allowing the nudibranch to escape.Rudman, W.B., 1999 (July 1) Cerata (ceras) in aeolids. nSea Slug Forum. Australian Museum, Sydney

Accessed 2014-9-10

References

External links

Sea Slug Forum
{{Gastropod anatomy Gastropod anatomy

Function

See also

References

External links