Nudibranch Families
Information sources within these pages: Nudibranch and Sea Slugs Identification 2 (Gosliner et al); Gary Cobb Nudibranch Central and Nudibranch ID apps; Wikipedia; Sea Slug Forum;
Actinocyclidae
Family members: Actinocyclus, Hallaxa
Description: Body is ovoid in shape with the dorusm convex in profile and smooth or covered with small pustules. The mantle is larger than the foot.
Rhinophores are bulbous, lamellate and retractile.
Gills form a tight, circular cluster like goblet around the posterior end of the dorsum which can retract into a pocket in the mantle.
Actinocyclidae are usually very cryptic upon their food source.
Aegiridae
The body of Aegiridae are high with spicules.
The rhinophores are smooth and are able to retract into raised sheaths or pockets with flaps.
The gills are either bipinnate or tripinnate and protected with tubercules.
They feed on calcaerous sponges.
Aeolididae
Family members: Aeolidiella, Anteaeolidiella, Baeolidia, Bulbaeolidia, Cerberilla, Limenandra, Protaeolidiella, Spurilla
Description: Elongate body with back crowded in regularly spaced and opaque cerata. The cerata can vary from flattened to cylindrical and tapering
The foot is usually wider than the body and the anterior corners are enlarged and either angular or tentacular.
Oral tentacles are long. Rhinophores can be smooth or annulate or with clubs that are lamellate or papillate
The majority prey upon sea anemones
Aglajidae
Family members: Aglaja, Chelidonura, Melanochlamys, Niparaya, Noalda, Odontoglaja, Philinopsis
Description: Body is long and rounded in appearance with striking colours or markings.
The headshield is large, most often triangular in shape with sensory bristles on the broader anterior edge near the mouth with lateral corners frequently lobed.
The posterior of the body has a pair of tails that can be blunt or elongate.
Apataidae
Family members: Tularia
Description: Body elongate with long tapering oral tentacles, and shorter, but similarly shaped, rhinophores which sometimes can have a wrinkled ventral section.
Cerata are arranged in spaced rows with the first two rows of cerata on each side close together with subsequent cerata rows regularly spaced at wider intervals.
The body can be white to a reddish orange or yellowish tinge with small brownish spots scattered all over the body. A yellow, orange, green or reddish brown line runs down the side of the body near the cerata.
Aplysiidae
Family members: Aplysia, Bursatella, Dolabella, Dolabrifera, Notarchus, Petalifera, Phyllaplysia, Stylocheilus, Syphonota
Description: The head is distinct with prominent oral tentacles and groover rhinophores.
Some species of Aplysiidae are able to swim by flapping their large parapodia.
They are able defend themselves by expelling a thick cloud of ink.
Arminidae
Family members: Armina, Dermatobranchus, Heterodoris
Description: The body is long flattened and elongate. The mantle is large with longitudinal ridges running down the back.
The rhinophores are retractile club-like at the front of the nudibranch and positioned close together.
The gills on Armina are located down the sides under the mantle brim.
They feed on soft corals and sea pens
Bornellidae
Family members: Bornella
Description: A small cryptic family slugs with sheathed rhinophores and branched appendages used as gills. They feed upon hydroids.
Bullinidae
Family members: Bullina
Description: A small group of bubble-shell. They are nocturnal and found on sand, mud and gravel feeding on green algae.
They possess a mottled, ovate shell that it is possible for the animal to retract into.
They have a headshield with obvious eyes on the dorsal surface.
Cadlinidae
Previously the members of Cadlinidae were classified under the Chromodoridae family. The family consists of two genera being Aldisa and Cadlina.
They are ovate in shape with a convex dorsum. The mantle contains spicules giving it a rough appearance. The mantle possesses low rounded tubercles. Aldisa have a number of crater-like depressions on the midline of the notum.
The rhinophores are lamellate and can retract into separate pockets. They appear to be retracted when feeding. The gills can range from simple to complex, forming a circle around the anus and are able to retract into a pocket beneath the mantle.
Generally the Cadlina are plain in appearance being white or pale coloured sometimes with a coloured mantle margin and gill and rhinophore pockets. The Cadlina are usually found in temperate to polar zones, though the Aldisa species are tropical and somewhat more colourful.
Chromodorididae
Family members: Ardeadoris, Cadinella, Ceratosoma, Chromodoris, Diversidoris, Doriprismatica, Glossodoris, Goniobranchus, Hypselodoris, Mexichromis, Miamira, Thorunna, Verconia
Description: A large family of dorid nudibranchs that range in size from very small; tp very large. The body are generally smooth, elongate and brightly coloured and patterned. Chromodorididae means ‘sea nymph’.
The different taxa can be distinguished by some external features but are primarily distinguished by the radular teeth.
Dendrodorididae
Family members: Dendrodoris, Doriospilla
Description: The notum is covered in simple, spiculate tubercles, dorsal ridges or complex caryophylidia tubercles with a ring of protruding spicules and cilia.
They feed on sponges and normally found on rocky substrate.
Discodorididae
Family members: Asteronotus, Atagema, Carminodoris, Discodoris, Geitodoris, Halgerda, Jorunna, Otinodoris, Paradoris, Peltodoris, Platydoris, Rostanga, Sclerodoris, Sebadoris, Thordisa
Description: The body tends to ovate and flattened. They have broad and thick mantles covered in small spicules (tiny spike-like structures). The mantle surface varies with smooth, ridges, tuberculate or pustulose.
The rhinophores are retractable into pockets with raised sheaths and are lamellate. The pockets themselves can have rims that are smooth, pustolose or papillate.
The oral tentacles are conical or tentacular.
In South Asia Pacific, there is not alot of scientific study so morphology is the only identifier. There may be other species discovered through molecular study.
They feed on sponges.
Dorididae
Family members: Alloiodoris, Aphelodoris, Doris, Halgerda, Taringa
Description: The body is ovulate and frequently covered in tubercles or pustules. The gills that are retractile into separate pockets. The rhinophores are also retractable into pockets with raised sheaths.
The oral tentacles are shaped like an ear or earlobe (auriculate)
They feed on sponges.
Dotidae
Family members: Doto, Kabeiro
Description: A small species of nudibranch. The body is elongate covered with nodular cerata with spherical lobes that resemble a bunch of grapes.
The rhinophores sheaths are cylindrical and cup-like with a long cylindrical smooth rhinophore in the centre.
Dotidae feed on hydroids.
Facelinidae
Family members: Austraeolis, Caloria, Cratena, Echinopsole, Facelina, Favorinus, Herviella, Jason, Moridilla, Myja, Noumeaella, Palisa, Phidiana, Pleurolidia, Pteraeolidia, Sakuraeolis
Description: The bodies are elongate and slender with a tapering tail. The oral tentacles are long also long and tapering.
The rhinophores vary on species from simple to annulate (ring-shaped segments), to lamellate (plates or leaflets) or papillate (small finger-like projections).
The cerata are also varied ranging from long, tubular, tapering, curved, coiled or club-tipped. The surface is also variable being smooth, papillate, nodulose or tuberculate.
The arrangement of the cerata is also varied .
Facelinindae primarily feed on hydroids, however, some species feed on soft corals whilst others feed on eggs of opisthobranchs.
Flabellinidae
Family members: Flabellina
Description: The body is long and tapers into a pointed tail. The rhinophores are generally papillate without basal sheaths, however, they can also be smooth or even clubbed. The oral tentacles are long and taper into a point.
The cerata are long and thin and attach either directly to the body or to lobes. The tips of the cerata are cnidosac that contain nematocysts.
Flabellina feed on hydroids.
Fionidae
Family members: Abronica, Eubranchus, Fiona, Tenellia, Tergipes
Description: Fionidae are generally small with an elongate body that tapers posteriously. The foot is often wider than the body. The oral tentacles are smooth and can be short or long. The rhinophores are long and smooth.
The cerata are tubular or fusiform. They are arranged obliquely down each side of the body and are sometimes positioned upon ridges. In Eubranchus the cerata are swollen or inflated in appearance showing the digestive glands.
They feed mostly on hydroids or corals.
Gastropteridae
Family members: Gastropteron, Sagaminopteron, Siphopteron
Description: The species are very small and commonly known as bat-wing slugs. The headshield is short and triangular. They have large parapodia and can use them to swim. The gill is plicate and observed between the body and the parapodium.
They are brightly coloured or patterned.
They are known to feed on siliceous sponges.
Glaucidae
Family members: Glaucus, Glaucilla
Description: The oral tentacles and rhinophores are much reduced compared to other aeolids.
The cerata are positioned on the side of the body on lobes, the arrangement of which determines the species. G. atlanticus are in a single plane, whereas G. marginatus are in multiple rows. They have large anterior lobes that supports their ability to float in pelagic environments.
They feed on floating colonial hydrozoans like the blue-bottle jellyfish, blue button and the by-the-wind sailor.
They are able to take on the stinging cells from their prey delivering their own painful stings.
Goniodorididae
Family members: Ancula, Goniodoridella, Goniodoris, Okenia, Trapania
Description: A small nudibranch with oblong bodies a prominent notal margin. The possess long rhinophores, that are tapered and lamellate. They are able to contract the rhinophore but have no pocket or sheath.
The gills are contractile but do no possess a pocket or sheath.
Species of the genus Trapania have an alongate body with a pair of curved extrarhinophoral and extrabranchial appendages.
Goniodorididae feed on bryozoan or ascidians. Trapania feed on orange sponges.
Gymnodorididae
Family members: Gymnodoris, Paliola
Description: They have soft and elongate bodies that are generally smooth though some may have small bumps (pustules).
They have lamellate non-retractile rhinophores.
Their gills are also non-retractile and small forming a simple circular arrangement around the anus. The shape and form are important in identification.
Gymnodorididae feed on other other nudibranchs and sea slugs (opisthobranchs).
Haminoeidae
Family members: Aliculastrum, Atys, Bakawan, Cylichnatys, Haloa, Haminoea, Haminoeidae, Lamprohaminoea, Liloa, Phanerophthalmus, Roxaniella, Vellicolla
Description: A small, thin ovate or cylindrical shelled sea slug that is able to fully withdraw into the shell.
The headshield is broad with posterior edges forming lobes. The eyes are located close to the surface and central.
They feed upon green algal turf.
Hancockiidae
Family members: Hancockia
Description: The body is elongate with a narrow foot. Rhinophores are tapering clubs with a crown-like sheath that extends to a rounded knob on the end. The mouth has a number of finger-like appendages on each side of it.
The cerata that number up to seven are evenly spaced along the body with large cerata clusters. They primarily feed on hydroids.
Hermaeidae
Family members: Aplysiopsis, Hermaea
Description: Members of Hermaeidae are very small. The Rhinophores are auriculate with a distinct step to the tip. The eyes are located behind the rhinophores on the side of its head.
They have two oral lobes projecting laterally above the mouth.
The cerata vary from elongate to tapering at the end and are often transparent paddle-shaped with the digestive branches visible. They feed on green and red algae.
Hexabranchidae
Family members: Hexabranchus
Description: Hexabranchidae contains only a single genus Hexabranchus, with two species, and has no subfamilies.
Janolidae
Family members: Galeojanolus, Janolus
Description: Branched sensory structure between the rhinophores called the carnuncle. Dorsum covered in dense cerata with or without branches of the digestive gland. The body shape is elongated and flattened.
The cerata becomie sticky when disturbed, and attaching to anything they come in contact with. They are able to shed cerata in order to escape.
They feed on bryozoans that are tree-like in shape.
Juliidae
Family members: Berthelinia, Julia, Tamanovalva
Description: A member of the Sacoglossa family, they posses two-valved shell that they can completely withdraw into.
The eyes are positioned behind the rhinophores that are joined to the head and are auriculate, often cylindrical.
They are pale to green in colour feeding upon green algae.
Myrrhinidae
Family members: Dondice, Godiva, Hermissenda and Phyllodesmium
Description: Members of Myrrhinidae have slender, elongate bodies with a wide foot and tapering tail.
The oral tentacles are long and tapering. The rhinophores in Phyllodesmium are smooth whereas the other members of this family have annulate rhinophores.
The shape of the cerata is wide ranging from long, tubering, tapering, curved, or curved only apically. These characteristics help visually identify the different species.
Feeding on soft corals or gorgonians to predating on other nudibranch.
Limapontoiidae
Family members: Costasiella, Ercolonia, Palcida, Sacoproteus, Stiliger
Description: The body is small and tapering with variably shaped cerata. Some are long and slender whilst others shorter and stout.
The rhinophores are long and simple. The eyes are visible normally between or behind the rhinophores. Costasiella are known for having eyes close together.
Generally they feed on green algae or some have been known to feed on eggs of other opisthobranchs.
Lomanotidae
Family members: Lomanotus
Description: The body is soft, slender, and elongate.
Along each side of the mantle edge is an undulating ridge with short, pointed cerata.
The rhinophores have transverse lamellae on the club with a blunt knob rising at the end. There are tall sheaths surrounding the rhinophores and these sheaths bear papillae around the lip.
They have one or two pairs of oral tentacles but no developed oral veil.
They feed upon hydroids.
Madrellidae
Family members: Madrella
Description: Madrellidae are closely related to Proctonotidae except they have an oral veil. The bodies are elongate with a broad mantle that tapers to a point in the tail.
The cerata are positioned from the anterior end around the body. They do not have cnidosacs, but instead have glands that produce a fluid when they are disturbed. They are also able to shed the cerata when distressed.
The rhinophores are not retractile and have a stalk with papillae clubs on the end.
They feed on bryoazoans.
Onchidorididae
Family members: Acanthodoris, Adalaria, Akiodoris, Calycidoris, Diaphorodoris, Doridunculus, Lamellidoris, Knoutsondonta and Onchidoris
Description: The mantle is broad and ovulate with many long papillae. The retractable rhinophores are long, slender and lamellate with pockets.
The gill is non-retractile, circle of branchiae around the anus. Each of the branchiae is separate and situated in its own individual pocket.
It feeds on bryozoans encrusted onto to rocks and boulders.
Oxynoidae
Family members: Lobiger, Oxynoe, Roburnella
Description: The body has an ovoid shell covering it with a long thick tail that can be used to swim. In some species they may also possess lateral parapodia that can also be used to swim. They are able to detach the tail and parapodia in the event of an attack allowing the body to crawl to safety.
The rhinophores are auriculate with the eyes sitting behind the them.
They feed on Caulerpa green algae.
Phyllidiidae
Family members: Ceratophyllidia, Phyllidia, Phyllidiella, Phyllidiopsis, Recticuldia
Description:
Plakobranchidae
Family members: Bosellia, Elysia, Pattaclaya, Plakobranchus, Thurdilla
Description: They are small to medium sized. The body is long and narrow with no cerata. Instead they have flap-like parapodia that runs from behind the head to the posterior end of the body. The parapodia are not used for swimming like some species of sea opisthobranchs. They are used for respiration in Plakobranchidae.
The tentacles are either predominately absent or very small. The rhinophores are prominent and auriclate
They feed on green algae or diatoms.
Pleurobranchidae
Family members: Berthella, Euselenops, Pleurobranchaea, Pleurobranchus
Description: The body is soft with a small internal shell or without a shell. The plume-like gills are located on the right hand side of the body and may be covered by the mantle. They are known as ‘side-gilled slugs’. Members of this species are known to grow to very large sizes. The body can be smooth or covered with evenly distributed pustules.
They produce an acidic defensive secretion.
Whilst not a nudibranch they are carnivores feeding on sponges, corals, anemones and ascidians.
Polyceridae
Family members: Crimora, Kalinga, Kaloplocamus, Limacia, Nembrotha, Plocamopherus, Polycera, Roboastra, Tambja, Thecacera
Description: Elongate in shape with a high dorsum.
Kaloplocamus and Plocamorpherus have pronounced tubercles along the lateral ridge. Plocamorperus has globular structures on some or all of the tubercles.
The rhinophores are lamellate and retractile.
The gills are are generally non-retractile, but those species that can do not possess a gill pocket. Genus of Nembrotha, Roboastra and Tambja have their gills high-up midway down the dorsum.
Polycerids feed on bryozoan.
Samlidae
Family members: Samla
Description: Samla have a long narrow body with cerata arranged in clusters on elevated rows.
The rhinophores are longer than the oral tentacles which are lamellate with the eye positioned at the base of each one.
They feed upon hydroids
Tethydidae
Family members: Melibe
Description: They range in size from small to very large. Their bodies are elongate body with a large extensible oral hood with fringing tentacles.
The rhinophores have small, lamellate clubs with large cylindircal or flattened rhinophoral sheaths that are similar to the cerata. The cerata are fluid-filled without branches of the digestive gland within.
They feed on small crustaceans using the fringing tentacles to detect prey and capture it in the oral hood that is held up in the current or cast over the substrate.
Tritoniidae
Family members: Mariona, Tritonia
Description: The bodies are elongate with with a high dorsum. They have paired secondary gill branches that have and rhinophores with a crown of papillae surrounding finger-like apices. The gill branches can be cryptic against their food source making them difficult to find.
They are known to eat soft corals, gorgonians and sea pens.
Mariona and Tritonia can only be differentiated by internal characteristics.
Tylodinidae
Tylodinids posses a limpet-like shell which the animal can withdraw entirely beneath.
The shell is a flattened conical shape, ovate and can be radially ribbed or smooth.
The body is smooth, bright, yellow and moderately large.
There are two pairs of longitudinally split, enrolled tentacles. The anterior pair are connected to an oral veil. The posterior pair are positioned high up on the head with the eyes below and to the centre of the head.
They feed on sponges.
Umbraculida
Family members: Umbraculum
Description: The body is circular shaped with large tubercules on the side. There is a shell that sits atop the dorsum that is often covered in plant or animal structures.
There are a pair of rolled tentacles with longitudinal slits located at the top of the head with the eyes in between them. The oral tentacles are located either side of the mouth.
There gills are not visible. They are located on the right side under the shell.
They feed on sponges.
Unidentiidae
Family members: Unidentia
Description: