Muck diving critter list – the creme de la creme of curious critters and muck species

Have you ever heard of muck or macro diving? Muck divers look beyond the ocean’s bigger animals and pristine environments, in favour of stark seabeds and murky waters. Why? Well despite the desolate appearance of these dive sites, there is often far more to discover than first meets the eye – including an array of magnificent macro species.

Often referred to as "critters", these often tiny animals are among some of the oceans' strangest and most interesting. Known for bold colours, crazy camouflage, and bizarre behaviour, they make up for their size with interesting and photo-worthy details. Plus, they're a challenge to spot, making sightings all the more memorable. 

Get ready to meet the creme de la creme of curious underwater animals, and learn our top tips for where to find them. 

These small, globular crustaceans qualify as supermacro. They are barely visible to the naked eye, growing to around 0.3 centimetres in length – dramatically smaller than an actual ladybug. Named for their colourful and often spotted exteriors, ladybug amphipods often look like small specks of debris, sitting on or moving around in soft coral. But, a powerful macro lens reveals their bodies in detail, including legs, antennae, and sweeping appendages used to capture their microscopic meals. 

• Top destinations – Bali, Lombok, Komodo
• Tips for finding – search the tops of sea squirts, hydroids, and crinoids for moving dots
• Get the shot – you’ll need a dioptre lens to shoot this insanely small supermacro species

Although you'd never guess it based on looks, this is actually one of the most poisonous animals in the ocean. The venom of a blue-ringed octopus is 1,000 times more powerful than cyanide, and each pint-sized cephalopod packs enough of it to kill 26 humans within minutes. Fortunately, this fascinating little octo is far more likely to flee than attack if threatened – but not before flashing a stunning psychedelic colour show of neon blue rings, making it a favourite among underwater photographers.

• Top destinations – southeast Australia, Lembeh Strait, Mabul, Anilao
• Tips for finding – scan rock and rubble bottoms in shallow water
• Get the shot – if possible, shoot on a dark background to show off the colours 

This is one of the hardest to spot critters out there, thanks to its expert disguise and size – around two centimetres in length when fully grown. Different species of pygmy seahorses have each adapted to look identical to the environments in which they live – in most cases, delicate sea fans and soft corals. Their camouflage includes colourful bumps and ridges that mimic the size and texture of coral polyps, allowing each sneaky seahorse to blend perfectly into the backdrop. 

• Top destinations – Raja Ampat, Milne Bay, Lembeh Strait
• Tips for finding – search for small colonies of five to six in gorgonian fans 
• Get the shot – shoot in side profile to avoid flashing lights in the eyes of this shy critter

With intense pulses and flashes of neon pink, purple, and yellow, this small cephalopod's colour show is nothing short of spectacular. And, because it's frequently spotted over drab silt and rubble bottoms during daylight hours, the flamboyant cuttlefish makes for an exceptional underwater photography subject. Keep an eye out for fascinating behaviour like "walking" along the bottom using two arms and shooting clouds of ink to confuse would-be predators.

• Top destinations – Lembeh Strait, Bali, Ambon
• Tips for finding – keep watch for walking motion over mucky bottoms 
• Get the shot – shoot video instead of photos to capture the full colour show 

This master of disguise uses chromatophores and papillae – colour and texture-changing skin tissues – to adjust its appearance like other octopuses. But, the appropriately named mimic octopus has a few other tricks up its eight sleeves. This crafty cephalopod imitates a variety of other oceanic species, including sea snakes, flatfish, sea anemones, and even lionfish. To perform all these costume changes, the mimic uses a variety of techniques, including partially hiding in the sand or free-falling through the water column.

• Top destinations – Anilao, Dumaguete, Ambon, Lembeh Strait
• Tips for finding – watch for arms used as lures or decoys sticking up from the sand
• Get the shot – try shooting in bursts to capture this fast mover without blurs 

While it might seem like the work of science fiction, we assure you the bobbit worm is very much real – and just as creepy as it looks! This giant carnivorous tube worm burrows under the sand, striking out at unsuspecting prey as it passes by, and it can reach an astonishing three metres in length. Yuck! A bobbit worm's hideous front end is outfitted with oversized antennae and sharp mandible jaws, giving it the look of a supersized insect.

• Top destinations – Bali, Lembeh Strait, Anilao 
• Tips for finding – dive at night with low-lumen torches, as tube worms are light sensitive
• Get the shot – your flash will make the worm retreat, so you get one shot – make it count

Frogfish are strange animals to start with, and this is perhaps the most bizarre of them all. The psychedelic frogfish is incredibly rare, having been sighted only in a tiny region of Molucca – another of Indonesia's muck diving meccas, Ambon. This cryptic creature spends its time sandwiched between stones or huddled in a hole, using its swirling, fingerprint-like pattern to pose as a piece of coral. A true ambush predator, this species lacks a lure, instead lying perfectly still while waiting for prey to approach. 

• Top destinations – Ambon
• Tips for finding – only one or two are spotted each season and always by local guides
• Get the shot – remember that your strobe can stun this rare and light sensitive creature

This transparent nudibranch looks like a strange pile of strings at first, but what you're actually viewing are its internal organs. And, the wispy ghost-like frills on its topside are external gills. Sometimes referred to as the "holy grail of nudibranchs", this strange slug's transparent body makes it incredibly difficult to find. One way that you might get lucky is to watch the bottom for movement. This nudi is always on the move, scouring the silt for anything it can get its gaping mouth around.

• Top destinations – Anilao, Romblon, Mabul, Lembeh Strait
• Tips for finding – hover over the silt and rubble and wait for movement 
• Get the shot – shoot on a dark background to pick up the slug's organs

These pint-sized crustaceans are surprisingly strong, working in small groups to take down prey vastly larger than themselves. Their favourite dish? Sea stars. Even the giant venomous crown of thorns isn't safe from these voracious and tenacious little shrimp, who keep their live prey subdued as they consume it slowly, sometimes over the course of weeks. Harlequin shrimp are surprisingly photogenic, often waving their brightly coloured claws for the camera and perching atop backdrops of neon red and purple. 

• Top destinations – Bali, Lembeh Strait, Similan Islands, Mergui Archipelago
• Tips for finding – search the tops and sides of starfish, the shrimp's primary food source
• Get the shot – don’t overexpose your shots, less is more on the shrimp’s white details

Named for its adorable facial features, this tiny macro critter tops out at five centimetres and is one of the hardest animals on this list to spot. And, despite its appearance, this fascinating little creature isn't technically a nudibranch – it's actually a "solar-powered" sap sucking slug. This photographers' favourite spends its days chomping away slowly at underwater foliage and then using the chlorophyll within the consumed plant matter to photosynthesize, thereby gaining its energy from the sun. 

• Top destinations – Bali, Lembeh Strait, Japan 
• Tips for finding – search for these guys in the shallows where they can easily photosynthesize 
• Get the shot – remember to focus on the eyes for a dead-on macro shot in perfect focus

Famous for their flashy displays, these brightly coloured dragonets make exciting and challenging underwater photography subjects. They emerge for just a short period around dusk, and remain in near-constant motion during their elaborate mating dance. Male mandarinfish often have the brightest colours, a pronounced dorsal fin, and a larger body – they can reach a length of over seven centimetres – and you’re more likely to see them free swimming as they court their mates. Females are smaller and more streamlined and will be seen perched on the reef taking in the male mandarinfish show.

• Top destinations – Bali, Lembeh, Mabul, Malapascua 
• Tips for finding – arrive a few minutes before dusk to catch the first females emerging from the reef
• Get the shot – shoot in bursts for a better chance at catching these shy and fast critters with no blur