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Sea Slugs

Sea Hares, Pteropods & Umbrella Shells

Sea Hares, Pteropods & Umbrella Shells



Index

Sea Slugs



Side-Gilled

Side-Gilled Slugs

Umbrella Shells

Umbrella Shells

Head-shield Slugs

Head-shield Slugs

Pteropods

Pteropods

Sap-Sucking Slugs

Sap-Sucking Slugs

Sea Hares

Sea Hares

Nudibranchs



Phanerobranch Dorids

Side-Gilled Slugs

Cryptobranch Discodorids

Cryptobranch Discodorids

Cryptobranch Chromodorids

Cryptobranch Chromodorids

Radula-less Dorids

Radula-less Dorids

Arminids

Arminids

Dendronotids

Sap-Sucking Slugs

Aeolids

Aeolids

The bizarre planktonic sea butterflies couldn't be more different from the red-algae grazing sea hares, or the huge umbrella "shells".

Pteropoda



These pelagic opistobranchs migrate through the water column, coming towards the surface during dark nights. In cold waters some such as the sea butterflies (Cymbulia) occur in such numbers that they are an important food source for whales, penguins and fish. In Indo-pacific waters they can also be common though not in such numbers.

Clavelina tridantata can sometimes be seen in huge numbers on black water dives. The light brown protoconch can be clearly seen through the transparent body. After such mass gatherings, masses of protoconchs can be found on reefs and washed up on beaches.

Cavolinia tridentata
Creseis clava
Cymbulia peronii

Anaspidea



Sea Hares have an internal shell, and are well-camoflaged algae eaters. Many are large to very large and can swim. Some species can release a jet of pigment in defense, but unlike the pigment of an octopus or squid, it is not mucous bound and this disperses quickly.

They often have good chemical defenses, and produce slime to deter predators. A number of species are collected for food.

Petalifera ramosa
Notarchus indicus?
Aplysia parvula
Aplysia argus

Umbraculoidea



Umbraculum umbraculum is the Umbrella Shell a diver is most likely to encounter. It is large, night-active, has a flat shell on its' upper surface.

Umbraculum umbraculum

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Pteropoda

Pteropoda

These pelagic opistobranchs migrate through the water column, coming towards the surface during dark nights. In cold waters some such as the sea butterflies (Cymbulia) occur in such numbers that they are an important food source for whales, penguins and fish. In Indo-pacific waters they can also be common though not in such numbers.

Clavelina tridantata can sometimes be seen in huge numbers on black water dives. The light brown protoconch can be clearly seen through the transparent body. After such mass gatherings, masses of protoconchs can be found on reefs and washed up on beaches.

Cavolinia tridentata
Creseis clava
Cymbulia peronii

Anaspidea

Anaspidea

Sea Hares have an internal shell, and are well-camoflaged algae eaters. Many are large to very large and can swim. Some species can release a jet of pigment in defense, but unlike the pigment of an octopus or squid, it is not mucous bound and this disperses quickly.

They often have good chemical defenses, and produce slime to deter predators. A number of species are collected for food.

Petalifera ramosa
Notarchus indicus?
Aplysia parvula
Aplysia argus

Umbraculoidea

Umbraculoidea

Umbraculum umbraculum is the Umbrella Shell a diver is most likely to encounter. It is large, night-active, has a flat shell on its' upper surface.

Umbraculum umbraculum