Phylum Mollusca / Class Gastropoda / Order Nudibranchia

Nudibranchs belong to sea slugs. As all other gastropods, they are slow moving bottom dwellers. They have soft bodies and most of them lack an external protective shell. Their secondary gills are exposed outside, as reflected by their neo-latin/greek name "nudibranch" meaning "nude/naked gills". Some nudibranchs have numerous body projections (called "cerata") increasing the overall body surface and enhancing breathing. Nudibranchs carry a pair of horn-like cephalic tentacles or "rhinophores" at the front, that are used primarily as chemosensory organs (sensing chemicals). To protect themselves from predators many developed toxic or bad tasting glands in the skin, and their bright colors warn predators of their horrible taste. Aeolid nudibranchs developed another amazing strategy to protect themselves from predators. They extract nematocysts from the coelenterates on which they feed and store them in the special sacs at the tips of their ceratas called cnidosacs. Nematocysts, located in the specialized cells "nematocytes" of coelenterates, are the stinging weapons used for catching food and for defence. Aeolids steal these weapons and discharge them when needed in their own defence.

Nudibranchs possess fantastic coloration and color patterns. They deserve to be called gems of the sea and should inspire jewelry designers (they shouldn't be called "slugs"). Only some polyclad marine flatworms can rival their beauty, although the latter have simpler body architecture. Finding a new nudibranch is always a very special and exciting moment. Nature's boundless creativity, that produced these unpredictable forms and color patterns, keeps surprising and stimulating your imagination. Fortunately these animals are so diverse, that there is little risk that you will see all of them... and get bored.
Nudibranchs cannot be taken away or preserved - they loose their shape and colors. This protects the beautiful creatures from the risk of being fished out by tourists, collectors or for sale. The best way to bring a nudibranch home with you is to take a photograph. They cannot be kept in an aquarium because of their narrow dietary range and maybe other factors (microelements, system stability etc). Even in the sea they are more or less confined within special micro-environments, providing them with specific food and micro-conditions. Reconstructing such micro-environment artificially is a complex research challenge. Therefore, the best way to see them is in their natural habitat - the ocean.
Let's go diving...
Atagema intecta Bornella stellifer Bornella anguilla Cadlinella ornatissima
Ceratosoma gracillimum Ceratosoma trilobatum Chelidonura punctata Chromodoris annae
Chromodoris annulata Chromodoris coi Chromodoris conchyliata Chromodoris decora
Chromodoris dianae Chromodoris fidelis Chromodoris geminus Chromodoris geometrica
Chromodoris hintuanensis Chromodoris kuniei Chromodoris leopardus Chromodoris magnifica
Chromodoris cf. reticulata / tinctoria Chromodoris willani Cuthona sibogae Cuthona yamasui
Dendrodoris denisoni Discodoris boholiensis Elysia ornata Flabellina rubrolineata
Glossodoris atromarginata Glossodoris cruenta Glossodoris sp. Glossodoris stellatus
Glossodoris rufomarginata Halgerda batangas Halgerda tessellata Hexabranchus sanguineus
Hypselodoris apolegma Hypselodoris emma Hypselodoris bullocki Hypselodoris infucata
Hypselodoris kaname Hypselodoris maculosa Hypselodoris mouaci Hypselodoris nigrostriata
Hypselodoris purpureomaculosa Hoplodoris estrelyado Jorunna funebris Jorunna rubescens
Mexichromis multituberculata Nembrotha cristata Nembrotha kubaryana Nembrotha lineolata
Nembrotha milleri Notodoris serenae Phestilla melanobrachia Phidiana indica
Phyllidia cf. elegans Phyllidia ocellata Phyllidiopsis fissuratus Phyllidiella zeylanica
Platydoris formosa Pleurobranchus cf. forska Pteraeolidia ianthina Risbecia pulchella
Risbecia tryoni Roboastra luteolineata Tambja morosa Tambja sp.
Thecacera sp. Unidentified 2
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