25 Benthic families - ReefoDivers

Study these 25 benthic families for our bronze level certificate.

Brown or olive-green in color
Providing habitat and food

Brown algae

Broad oral disk
Short tentacles
Upturned mouth in centre

Corallimorph

Flattened body
Exoskeleton
Single pair of claws

Crab

Hard calcium crust
Substrate for coral larvae

Crustose coralline algae

Calcium carbonate shell
Tentacles and sensory organs
Sea snails feed on algae

Sea snail

Flattened body shape
Opening both mouth and anus

Flatworm

Bright green color
Provide food and oxygen
Recycle nutrients

Green algae

Calcium carbonate skeleton
Reef builders
Polyps with x6 tentacles

Hard coral

Colonial animal
Growing on rocks
Bushy appearance

Hydroid

Umbrella-shaped bell
Trailing tentacles
Transparent appearance

Jellyfish

Tough exoskeleton
Pair of large claws
Long sensory antennae

Lobster

Sea snail without shell
Exposed respiratory gills

Nudibranch

Soft, bag-like body
Eight long tentacles
Tentacles lined with suckers

Octopus

Red in color
Blade structure

Red algae

Tubular body
Long tentacles
Inward turning mouth
Flat base attachment

Sea anemone

Long cylindrical body
Tiny tube feet
Filter-feeder

Sea cucumber

Narrow leaves and roots
Stabilize sediment

Sea grass

Five-point radial symmetry
Preying on mollusks

Sea star

Hard calcareous structure
Moveable spines

Sea urchin

Hard exoskeleton
Long, slender antennae
Often translucent

Shrimp

Polyps with x8 tentacles
Lack a hard skeleton

Soft coral

Simple body plan
No true tissues or organs
Filter water and recycle nutrients

Sponge

Built like a barrel
Two openings called siphons
Filter water and recycle nutrients

Tunicate

Growing as a dense mat
Living on muds and sands

Turf algae

Look like tiny sea anemones
Living in colonies
Tentacles are all marginal

Zoanthid