Marine life  /  Sea snails & shells
26 of 1316 species
Group

Sea snails & shells

The molluscs with a shell: sea snails, cowries, cones, conches, chitons and the bivalves. The sea slugs, which are also gastropods and have lost the shell, have their own group.

Species
26
Depth
0–50 m
Rarity range
1 star of 5, found on most divesto 4 stars of 5, two or three a season
Night only
18
Can hurt a diver
3
Destinations
11

The living animal is usually more interesting than the shell, and often covers it. A cowrie or an ovulid draws its mantle up over the shell, so the pattern seen underwater belongs to the living tissue and the shell beneath it is plain. The flamingo tongue is the clearest example: the leopard spots are on the mantle, not on the shell.

Most are found by knowing what they feed on. The ovulids are on the sea fan or soft coral they eat, the harp shells hunt crabs after dark, the nassarius snails surface within seconds of anything dying nearby, and the tritons hunt sea stars and sea cucumbers. The carrier shell cements dead shells and stones to its own as it grows.

The cone shells are the one group on a reef that should never be picked up. They hunt with a harpoon that can be fired in any direction including backwards, and the sting from the fish-eating species is a medical emergency. A cone shell in sand looks like an ordinary shell and that is the whole problem.

The bivalves here are the clams, scallops and oysters. The giant clams farm algae in the coloured mantle tissue along the shell margin, which is where their colour comes from and why they sit open in the light.

26 species

Photographed first, then commonest

26 written up, none photographed yet

Every one has a page. They are shown as a list rather than as pictures because nothing has been photographed or logged for them yet, and a species with nothing behind it should not sit in front of one that has.

Where they are recorded

How many of the 26 carry a record at each destination. A species usually carries several, so these do not add up to 26.

Lembeh Strait 17 Bali 16 Anilao 15 Dauin & Dumaguete 15 Ambon 10 Papua New Guinea 10 Florida 5 Bahamas 5 Cayman Islands 5 Red Sea 1 Australia 1

The other groups

Anemonefish 11 Angelfish 25 Batfish 3 Blennies 26 Butterflyfish 35 Cardinalfish 13 Damselfish 32 Dottybacks 5 Dragonets 5 Eels & garden eels 18 Flatfish 8 Frogfish & anglers 26 Goatfish 8 Gobies & dartfish 29 Groupers & anthias 42 Hawkfish 5 Jacks & open-water fish 29 Jawfish 4 Lizardfish & flatheads 10 Morays 26 Morwongs & trumpeters 4 Parrotfish 16 Pufferfish & boxfish 23 Rabbitfish 5 Scorpionfish & lionfish 47 Seahorses & pipefish 53 Shrimpgobies 17 Snappers, breams & sweetlips 39 Squirrelfish & soldierfish 9 Surgeonfish & unicornfish 26 Triggerfish & filefish 25 Trumpetfish & cornetfish 4 Wrasses 56 Other fish 46 Sharks & rays 63 Turtles, sea snakes & crocodiles 11 Marine mammals & birds 10 Cephalopods 36 Nudibranchs & sea slugs 137 Shrimps 38 Mantis shrimps 5 Crabs 45 Hermit crabs 10 Lobsters & squat lobsters 13 Isopods & parasitic crustaceans 5 Amphipods 2 Sea stars 18 Brittle stars & basket stars 7 Feather stars 2 Sea urchins 23 Sea cucumbers 12 Worms 11 Flatworms 3 Jellyfish & stinging drifters 10 Anemones & zoanthids 12 Corals & sponges 29 Sea squirts 4 Blackwater & plankton 52 Other invertebrates 2

All 1316 species in one index, with filters for destination, rarity and hazard.

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