macro
Nudibranchs.
Various
Nudibranchs are the jewels of the reef — shell-less sea slugs in a riot of electric colours and bizarre forms, beloved by macro photographers. Their dazzling colours are usually a warning: many recycle the toxins, or even the stinging cells, of the prey they eat. Despite their delicacy, they are fierce specialist predators.
Size
Mostly < 5 cm
Weight
Negligible; body size ~4 mm to ~60 cm depending on species.
Diet
Specialist feeders — sponges, hydroids, anemones, tunicates or other animals' eggs.
Lifespan
Short — usually months up to about a year.
Depth
Intertidal shallows to deep water; most reef species in the shallows.
Reproduction
Simultaneous hermaphrodites — pairs fertilise each other and lay eggs in coiled ribbons.
Snorkel or dive
Dive (macro)
Best season
Year-round
Conservation
Not assessed
How to recognise it
Vividly coloured shell-less sea slugs in hundreds of species.
Behaviour
Slow grazers on rubble, sponges and reef walls; toxins advertised by bright colours.
Where to see it in the Maldives
Hundreds of species recorded; best searched slowly on rubble and walls (Macro Spot, Gan Inside).
Conservation
No broad threats; sensitive to reef degradation and loss of specific prey.
IUCN · Not assessed
Watch them responsibly
Never touch or relocate them — they're fragile and tied to specific food; don't stir sediment over them.
Many steal stinging cells from their prey and reuse them for their own defence.
Many store their prey's still-functional stinging cells in their finger-like cerata, reusing them for defence.
Want to dive with nudibranchs?
Our Maldives specialists match you to the right atoll, season and resort.
More macros
Sightings are typical, not guaranteed — encounters vary with season and conditions.