Field Guide · Chapter 13 of 29

Fish and sea life

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Elasmobranchii › Lamniformes › Lamnidae

Great white shark

Up to 6 m long

It has about 300 teeth, and they keep being replaced for its whole life.

Elasmobranchii › Orectolobiformes › Rhincodontidae

Whale shark

Record: 18.8 m long

The whale shark is the largest known extant fish species.

Elasmobranchii › Carcharhiniformes › Sphyrnidae

Great hammerhead

Up to 6.2 m long

The great hammerhead cuts its drag by swimming on its side.

Elasmobranchii › Myliobatiformes › Myliobatidae

Giant manta ray

Up to 9 m long

The manta has the largest brain of any fish, and it is not a small one.

Perciformes › Scombridae

Atlantic bluefin tuna

Up to 910 kg

A female can lay up to 10 million eggs in one spawning period.

Salmoniformes › Salmonidae

Atlantic salmon

Up to 1 m long

Unlike Pacific salmon, the Atlantic salmon can survive spawning and go back to sea to spawn again.

Syngnathiformes › Syngnathidae

Short-snouted seahorse

Up to 15 cm long

In this species the father carries the young, and the male goes through pregnancy and labour.

Perciformes › Pomacentridae

Ocellaris clownfish

About 11 cm long

Every one starts out male, and any of them may later become female.

Tetraodontiformes › Molidae

Ocean sunfish

Up to 3.3 m long

Its skeleton is mostly cartilage, which lets it grow to sizes impractical for other bony fishes.

Anguilliformes › Anguillidae

European eel

Rarely 1.33 m long

No one has yet watched one mate in the wild.

Scorpaeniformes › Scorpaenidae

Red lionfish

Up to 47 cm long

A reef fish from the Indo-Pacific that has spread into the Caribbean and up the US East Coast.

Cephalopoda › Octopoda › Enteroctopodidae

Giant Pacific octopus

Arm span up to 4.3 m

The giant Pacific octopus is the largest octopus species on earth.

Cephalopoda › Sepiida › Sepiidae

Common cuttlefish

Mantle up to 45 cm

It can change its skin colour while still inside the egg.

Scyphozoa › Semaeostomeae › Ulmaridae

Moon jellyfish

25 to 40 cm across

A see-through jellyfish whose four horseshoe-shaped gonads show through the top of its bell.

Hydrozoa › Siphonophorae › Physaliidae

Portuguese man o' war

Tentacles up to 30 m

It looks like a jellyfish, but it is a colony of many zooids that act as one animal.

Malacostraca › Euphausiacea › Euphausiidae

Antarctic krill

Up to 30,000 per m3

A shrimp-like animal, one of the most abundant species on the planet, swarms in the Southern Ocean.

Anthozoa › Scleractinia › Acroporidae

Staghorn coral

Over 2 m (6.5 ft) tall

In a year it can add up to 5 cm of skeleton for every 1 cm it already has.

Asteroidea › Forcipulatida › Asteriidae

Ochre sea star

Rays up to 25 cm

It is thought one sea star can eat eighty mussels in a year.

Malacostraca › Decapoda › Nephropidae

American lobster

As much as 20 kg

The heaviest crustacean in the world, and the heaviest living arthropod species.

Bivalvia › Cardiida › Cardiidae

Giant clam

Shell up to 1.5 m long

Its mantle is a home for algae, and the algae supply most of the clam's food.

Merostomata › Xiphosurida › Limulidae

Atlantic horseshoe crab

Females up to 60 cm

Its blood is bled for medical tests, and then the crab goes back to the sea.

Malacostraca › Decapoda › Coenobitidae

Coconut crab

Up to 4.1 kg (9.0 lb)

Adults give up their shell and grow a tough armour plate on the abdomen.

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