''Antiopella cristata'', sometimes known by the common name crested aeolis, is a

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 ...

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 matc ...

, a

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 * ...

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 ...

mollusc 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 esti ...

in the

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 ...

Janolidae.

Taxonomy

Previously some authors synonymised ''Antiopella'' with ''Janolus'' and assigned the genus ''Janolus'' to the Janolidae family (see ITIS.gov or AnimalDiversity), others (see Seaslug Forum) to the family of Zephyrinidae, and these were synonymised names of

Proctonotidae Proctonotidae is a family of sea slugs, nudibranchs, marine gastropod molluscs, in the clade Euthyneura Euthyneura is a taxonomic infraclass of snails and slugs, which includes species exclusively from marine, aquatic and terrestrial gastro ...

(see WoRMS). In 2019 an integrated taxonomic study reinstated ''Antiopella'' and ''Janolus'' as separate genera and placed them in the family Janolidae.

Description

This species is semi-transparent and has an oval-shaped outline. It is cream or light brown in colour, and grows to approximately 7.5 cm in length. The head has oral tentacles that are short. The lateral

cerata :''The tortrix moth genus ''Cerata'' is considered a junior synonym of ''Cydia. Cerata, singular ceras, are anatomical structures found externally in nudibranch sea slugs, especially in aeolid nudibranchs, marine opisthobranch gastropod mollusks ...

are numerous, have a smooth surface and an inflated appearance. The central digestive gland lobe is thin and brown in colour and can be seen through each ceras. These gland lobes divide at the tip of the cerata into numerous terminal branches, distinguishing Janolids from Aeolid nudibranchs. The tips of the cerata are bluish-white and iridescent. The white surface colouration that is present on the cerata also appears in patches or lines along the bare central dorsum, as well as around the lamellate

rhinophore A rhinophore is one of a pair of chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, marine gastropod opisthobranch mollusks such as the nudibranchs, sea har ...

s and on the metapodium. The rhinophores are joined together at their bases with a swollen and wrinkled accessory caruncle. Both the rhinophores and median sensory caruncle are somewhat darker in colour than the rest of the body.

Distribution

''Antiopella cristata'' has been found as far north as

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

down through the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

and the French Atlantic coast. It has also been recorded in Moroccan waters as well as in the western

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 ...

Habitat

It is found at depths of up to 40 metres, only in calm, clean water, on hard substrata in the

sublittoral zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

Biology

''Antiopella cristata'' eats erect

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...

ns of the species '' Alcyonidium gelatinosum'', ''

Bicellariella ciliata ''Bicellariella ciliata'' is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water on both sides of the Atlantic Ocean, the Mediterranean Sea and the Indo-Pacific region. Description ''Bicellariella ciliata'' is a ...

'' and in the genus ''

Bugula ''Bugula'' is a genus of common colonial arborescent bryozoa, often mistaken for seaweed. It commonly grows upright in bushy colonies of up to 15 cm in height.Bock, P. (2015). Bugula Oken, 1815. In: Bock, P.; Gordon, D. (2015) World List of ...

'' and '' Bugulina'', such as ''

Bugulina turbinata ''Bugulina turbinata'' is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea. Description ''Bugulina turbinata'' is a colonial bryozoan that forms sm ...

'', ''

Bugula plumosa ''Crisularia plumosa'' is a species of bryozoan belonging to the family Bugulidae, commonly known as the feather bryozoan. It is native to the Atlantic Ocean. Description ''Crisularia plumosa'' is a colonial bryozoan that forms small bushy clum ...

'', ''

Bugula neritina ''Bugula neritina'' ( commonly known as brown bryozoan or common bugula) is a cryptic species complex of sessile marine animal in the genus ''Bugula''.Gordon, D. (2015). Bugula neritina (Linnaeus, 1758). In: Bock, P.; Gordon, D. (2015) World Lis ...

'' and possibly species in the genus ''

Cellaria ''Cellaria'' is a genus of bryozoans belonging to the family Cellariidae. The genus has cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world ...

''.Gary R. McDonald, James W. Nybakken
A List of the Worldwide Food Habits of Nudibranchs
in University of California Santa Cruz. The spawn of this species appear as a light pink or white string forming a wavy, circular pattern. The eggs themselves are contained within packets with transparent patches in between. This gives them the appearance of beads.

Gallery

File: Janoluscristatus.jpg, ''Antiopella cristata'' depositing eggs File: Proctonotidae - Janolus cristatus-001.JPG, ''A. cristata'' in the

Ligurian Sea The Ligurian Sea ( it, Mar Ligure; french: Mer Ligurienne; lij, Mâ Ligure) is an arm of the Mediterranean Sea. It lies between the Italian Riviera (Liguria) and the island of Corsica. The sea is thought to have been named after the ancient L ...

( Levanto) File:Janolus cristatus (della Chiaje, 1841).jpg, ''A. cristata'' on ''

Reteporella grimaldii ''Reteporella grimaldii'' is a species of bryozoans in the family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the fa ...

'' File: Blauwtipje kruipend over de bodem en met eitjes-4931703.webm, Two ''A. cristata'' crawl across the bottom. Video clip

References

External links

DORIS - Données d'Observations pour la Reconnaissance et l'Identification de la faune et la flore Subaquatiques
* {{Taxonbar, from=Q3162076 Proctonotidae Molluscs of the Atlantic Ocean Molluscs of the Mediterranean Sea Gastropods described in 1841 Taxa named by Stefano delle Chiaje Articles containing video clips