Marine Creatures Guide

At first glance, barnacles look like lumpy white volcanoes cemented to rocks, pier pilings, and boat bottoms - hardly the sort of creature to inspire wonder. But look closer, and you'll discover one of evolution's most bizarre success stories. These are not mollusks, but crustaceans - cousins to shrimp and crabs - who, in an evolutionary plot twist, decided to stand on their heads, glue themselves in place, and kick food into their mouths with their feet. They produce the strongest natural adhesive known, can survive being frozen solid, possess the animal kingdom's longest penis relative to body size, and have larvae that look like tiny aliens. For divers, barnacles are the textured white crust covering seemingly every hard surface underwater - ubiquitous, ancient, and utterly fascinating once you understand their secret lives.

Few fish inspire the same mix of awe and unease as the barracuda. With their torpedo-shaped bodies, jutting lower jaws packed with razor-sharp teeth, and unblinking stare, they look like nature designed the perfect marine predator - and then cranked up the intimidation factor. Capable of explosive bursts reaching 40 mph, these "wolves of the sea" are ambush hunters that strike with lightning precision. For divers, encountering a solitary great barracuda hovering motionlessly in blue water, watching you with cold curiosity, is an unforgettable experience. But witness hundreds of barracudas swirling in a massive tornado-like school, and you'll see another side of these apex predators - social, synchronized, and absolutely mesmerizing.

The Beluga Whale is the "canary of the sea"—a pure white, highly vocal Arctic whale that looks like it's always smiling. With their flexible, bulbous forehead (the "melon") and no dorsal fin, they're perfectly adapted to life under ice. They're among the most social and vocal of all whales, producing an incredible variety of clicks, whistles, and chirps. Their name means "white" in Russian, and their pure white coloration makes them stand out like ghosts in the dark Arctic waters. Encountering a beluga is like meeting an underwater snowman—curious, chatty, and surprisingly expressive.

The Blacktip Reef Shark is the classic "postcard shark" of the Indo-Pacific. If you’re wading in ankle-deep water in the Maldives or Tahiti and see a black-tipped triangular fin cutting through the surface, this is the culprit. They are the busiest sharks on the reef, constantly patrolling shallow lagoons and reef flats. While relatively small and timid, they are curious and will often investigate divers and snorkelers. They are the "managers" of the shallow reef ecosystem, keeping fish populations in check.

Boxfishes (family Ostraciidae) are slow, charismatic reef fishes wrapped in a rigid, box-shaped carapace built from interlocking hexagonal plates. They steer with tiny pectoral, dorsal and anal fins—an efficient “hover mode” called ostraciiform swimming—while their little puckered mouths peck at worms, crustaceans and sponges. Striking patterns and the famous yellow polka-dot juveniles make them crowd favorites, but they’re best admired gently: some species can release a detergent-like skin toxin if severely stressed.

If nature had a candy shop, the candy crab would be its most adorable product - a tiny, pastel-colored crustacean that looks like it was dipped in cotton candy frosting. Measuring barely 2 centimeters across, these miniature masters of disguise have perfected one of the ocean's most impressive camouflage acts: they not only match their soft coral host in color (from bubble-gum pink to lemon yellow), but they actually decorate themselves by plucking coral polyps and sticking them onto their shells like living costume accessories. The result is so convincing that even experienced divers can stare directly at a candy crab and see nothing but coral. For macro photographers, finding and photographing candy crabs is the ultimate treasure hunt - equal parts Where's Waldo and wildlife photography, requiring sharp eyes, patience, and a good guide who knows which soft coral heads to check.

Imagine decorating a coral reef for the holidays, and nature beat you to it - that's the Christmas tree worm. With twin spirals of feathery tentacles that look exactly like miniature decorated firs, these tiny polychaete worms add splashes of neon color to coral heads worldwide. But these aren't just pretty reef ornaments - they're sophisticated filter-feeding machines permanently embedded in living coral, armed with hair-trigger reflexes that make them vanish in a literal blink. Touch the water near one, cast a shadow over it, even swim too close, and SNAP - it disappears into its coral fortress in milliseconds, leaving you wondering if you imagined the whole thing. For macro photographers and patient divers, Christmas tree worms offer an endless game of "now you see me, now you don't" that never gets old.

Thanks to a certain animated fish who just kept swimming, clownfish are probably the world's most recognizable marine species. But the real story of these bright orange reef residents is far stranger - and more fascinating - than any Pixar script. Clownfish live their entire lives within the stinging tentacles of sea anemones, protected by a miraculous mucus coating that makes them immune to venom that would paralyze other fish. They're all born male and live in strict matriarchal societies where the largest fish is always female, and if she dies, the biggest male undergoes an irreversible sex change to take her place. For divers, clownfish offer a delightful paradox: they're simultaneously adorable and fiercely aggressive, defending their anemone homes by charging at creatures hundreds of times their size (including you), creating a comical David-vs-Goliath scenario where a 10cm fish genuinely thinks it can intimidate a 180cm human.

Cuttlefish are cephalopods in the order Sepiida, renowned for instantaneous camouflage, expressive signaling, and agile jet propulsion. Unlike octopuses, they have a porous internal shell called the cuttlebone that regulates buoyancy. With W-shaped pupils, eight arms plus two shootable feeding tentacles, and sophisticated vision (including polarization sensitivity), cuttlefish are versatile reef and sand-flat predators that hunt crustaceans and fishes.

Dolphins are the ocean's geniuses—intelligent, social, and endlessly curious. With their signature curved dorsal fin and beak-like snout, they are among the most recognizable and beloved marine animals. They use echolocation (biological sonar) to navigate and hunt, communicate with complex whistles and clicks, and display behaviors that suggest self-awareness and problem-solving. Encountering dolphins underwater is like meeting the ocean's ambassadors—playful, intelligent, and often as curious about you as you are about them.

The Dugong is the real-life mermaid—the gentle, seagrass-grazing marine mammal that inspired centuries of sailor's tales. With a fluked tail like a dolphin and a downturned snout perfect for rooting through seagrass beds, they are the ocean's "sea cows," spending their days peacefully munching on underwater meadows. Encountering a dugong underwater is like meeting a mythical creature that decided to become real—graceful, curious, and utterly peaceful.

Filefish (Monacanthidae) are the "hipsters" of the reef—flat, oddly shaped, and masters of looking like something they aren't. Closely related to Triggerfish but with softer bodies and a single prominent dorsal spine, they get their name from their rough, sandpaper-like skin. Instead of speed, they rely on extreme camouflage—drifting head-down to mimic seagrass or changing colors to match a gorgonian fan. From the alien-looking Scrawled Filefish to the tiny, cute Pygmy Leatherjacket, they are a diver's delight if you can spot them before they spot you.

Marine Flatworms are the "Magic Carpets" of the reef. Often mistaken for nudibranchs due to their dazzling colors, they are actually much simpler organisms—basically a 2D sheet of life with no heart, no lungs, and a single opening for both eating and pooping. Despite their simplicity, they are famous for their graceful, undulating swimming style (like a flamenco dancer's skirt) and their bizarre mating ritual known as "penis fencing."

Frogfishes are ambush predators in the anglerfish order (Lophiiformes), famed for extreme camouflage and lightning-fast strikes. They use a modified dorsal spine called the illicium tipped with a lure (esca) to attract prey, then engulf it with a powerful suction strike. With limb-like pectoral and pelvic fins, frogfish can “walk” along the seafloor and blend seamlessly into sponges, algae, or rubble.

Ghost pipefishes (family Solenostomidae) are delicate syngnathiform fishes related to seahorses and pipefishes but in their own family. They excel at mimicry—matching feather stars, algae, or hydroids—and often hang nearly motionless with heads slightly down. Females develop a distinctive brood pouch by fusing their enlarged pelvic fins, where fertilized eggs are incubated until hatching.

In the underwater world of bigger-is-better predators and flashy reef fish, gobies have taken the opposite evolutionary path - and made it spectacularly successful. With over 2,000 species making them one of the largest fish families on Earth, gobies have mastered the art of being small, savvy, and adaptable. Some are so tiny they're barely visible (the world's smallest vertebrate is a goby measuring just 7mm), yet they've evolved remarkable partnerships that would make any diplomat proud - like the famous shrimp-goby duo where a nearly-blind shrimp builds and maintains a home while its keen-eyed goby roommate stands guard at the door. For macro photographers and muck divers, gobies are endlessly fascinating subjects - hover gobies that "perch" on coral branches, pistol shrimp partners that communicate through antenna-touching, and neon cleaners that fearlessly enter predators' mouths. They're proof that in the ocean, small size is no barrier to evolutionary success.

The Grey Reef Shark is the "Boss" of the Indo-Pacific reefs. While Blacktips patrol the shallows and Whitetips nap in caves, the Grey Reef Shark rules the current-swept drop-offs. They are active, agile, and territorial predators often found patrolling in large schools. Famous for their distinct "threat display" (hunching their back and dropping their fins), they demand respect from divers. In places like Fakarava and Palau, you can witness the "Wall of Sharks"—hundreds of Grey Reefs hanging effortlessly in the blue current.

Few shark species inspire the same instant recognition as hammerheads - seeing that distinctive T-shaped head slicing through blue water is an unforgettable "only in nature" moment that reminds you evolution has no limits to creativity. But that bizarre hammer isn't just for show: it's a finely-tuned hunting instrument packed with hundreds of electroreceptors, providing 360-degree vision and the ability to detect stingrays buried under sand from meters away. Even more remarkably, these supposedly solitary apex predators gather in massive schools - sometimes hundreds or thousands strong - creating swirling walls of sharks that represent one of diving's most spectacular phenomena. For divers willing to venture to remote locations and brave strong currents, encountering a hammerhead school is a bucket-list experience that combines beauty, power, and a humbling reminder that in the ocean, you're just a visitor in their world.

Imagine a shrimp dressed for a ball - porcelain-white body adorned with purple and red spots, oversized paddle-shaped claws held delicately aloft like a dancer's arms. Now imagine that this exquisitely beautiful creature is actually a serial killer that specializes in torturing sea stars to death over the course of weeks. That's the harlequin shrimp: nature's gorgeous nightmare. These tiny crustaceans (barely 5cm long) are so hyper-specialized that they eat nothing but living starfish, which they hunt in monogamous pairs, flip upside down to immobilize, then slowly dismember and consume alive, starting with the arm tips and working inward. For divers, finding a harlequin shrimp pair during their gruesome feast is both mesmerizing and horrifying - like stumbling upon a crime scene where the perpetrator is too beautiful to arrest.

The Humpback Whale is the ocean's greatest showman—acrobatic, musical, and endlessly fascinating. With their extraordinarily long pectoral fins (up to one-third of their body length) and their famous breaching displays, they are among the most recognizable and beloved whales. They are the singers of the sea, with males producing complex songs that can last 20 minutes and be repeated for hours. They're also master strategists, using bubble net feeding to trap schools of fish. Encountering a humpback underwater is a once-in-a-lifetime experience—graceful, massive, and surprisingly curious.

If the ocean had a motorcycle gang, jackfish would be the members - sleek, aggressive, and traveling in coordinated packs that terrorize smaller fish with ruthless efficiency. Also called trevally (especially in the Indo-Pacific), these powerful predators combine raw speed, tactical intelligence, and pack-hunting cooperation into one silver-bullet package. The Giant Trevally, apex of the family, is legendary for explosive strikes, acrobatic leaps out of the water to catch birds mid-flight, and fights so powerful they've broken fishing rods and even dislocated anglers' shoulders. For divers, witnessing a school of jacks working a baitball - silver torpedoes flashing through clouds of prey - is like watching a perfectly choreographed underwater blitzkrieg. They're not just fish; they're ocean athletes at the absolute peak of aquatic performance.

Jellyfish are fascinating marine invertebrates belonging to the sub-phylum Medusozoa of the phylum Cnidaria. Despite their common name, they are not fish—they lack backbones, fins, and the typical anatomy of fishes.

The Lemon Shark is the smartest kid in the class—literally. Researchers love them because they are robust, survive well in captivity, and have demonstrated the ability to learn from each other (social learning), a trait once thought unique to mammals. Named for their yellowish-brown skin that blends perfectly with sandy sea floors, they are a favorite encounter for divers, especially in the Bahamas. With two dorsal fins of almost equal size (a rare trait in sharks), they cut a distinctive silhouette as they cruise the shallow flats.

The Mola mola, or Ocean Sunfish, is the heaviest bony fish in the world and arguably the weirdest. Looking like a giant floating head that lost its body, it can weigh more than a car and grow up to 3 meters tall. Despite their massive size, they feed almost exclusively on jellyfish, slurping them up like spaghetti. They are famous for "basking" sideways on the surface to warm up after deep, cold dives. Gentle, goofy, and infested with parasites, they are the holy grail for many divers, especially in places like Bali.

Nudibranchs, often called “sea slugs,” are among the most visually striking invertebrates in the ocean. Belonging to the subclass Opisthobranchia of the class Gastropoda, they are shell-less mollusks known for their vibrant colors and delicate forms. Their name “nudibranch” literally means “naked gills,” referring to the exposed feathery structures on their back used for respiration.

Nurse sharks (Ginglymostoma cirratum) are the "couch potatoes" of the shark world—but in the best way possible. These bottom-dwelling sharks are famous for their lazy daytime snoozing, often piled in adorable cuddle puddles of up to 40 individuals in caves and crevices. Don't let their chill vibes fool you—at night, they transform into suction-powered vacuum cleaners, using one of the strongest suction forces in the ocean to slurp up crabs, lobsters, and octopuses like aquatic milkshakes. With their distinctive whisker-like barbels, rounded pectoral fins, and carpet-shark Good looks, they're a favorite among divers for their docile nature and photogenic sleeping habits.

Octopuses are soft-bodied cephalopods famed for intelligence, dexterous arms, and exceptional camouflage. They possess eight arms lined with powerful suckers, a parrot-like beak, three hearts, and copper-based blue blood (hemocyanin). Lacking an internal or external shell, they squeeze through tiny gaps, eject ink to confuse predators, and use a jet of water from the siphon for rapid escape.

The Orca is the apex predator of the ocean—the largest dolphin and one of the most intelligent animals on Earth. With their striking black and white coloration and towering dorsal fin (up to 1.8 meters in males), they are instantly recognizable. They are master strategists, using sophisticated hunting techniques that vary by ecotype: some hunt fish in coordinated groups, while others specialize in taking down seals, whales, or even great white sharks. Encountering an orca underwater is both thrilling and humbling—you're in the presence of the ocean's ultimate predator.

Pilot Whales are the "cheetahs of the deep sea"—fast, powerful divers that can reach depths of 1,000 meters in pursuit of squid. Despite their name, they're actually large dolphins (the second largest in the dolphin family after orcas). With their rounded heads, dark coloration, and strong social bonds, they travel in tight-knit family groups led by matriarchs. They're known for their mass strandings—tragic events where entire pods beach themselves, possibly due to their intense loyalty to group members. Encountering a pod of pilot whales is like meeting an underwater family on a mission.

Pipefishes are seahorse relatives stretched into elegant living needles. They swim horizontally using rapid dorsal fin flicks and micro-adjust with tiny pectorals, hunting by vacuuming copepods and shrimp with a lightning suction snap of their long tubular snout. Like seahorses, males carry the eggs—from sticky belly patches to fully formed pouches— while many species sport striking bars or dots that make them underwater candy canes.

Porcupinefish (Diodontidae) are the "spiky balloons" of the sea. Often confused with pufferfish, they have a secret weapon: long, sharp spines that cover their body. Normally, these spines lie flat, making the fish look like a cute, wide-eyed puppy. But when threatened, they swallow water to inflate into a prickly sphere, turning from a snack into an unswallowable pincushion. With their big, soulful eyes and permanent "smile" (thanks to their beak-like teeth), they are among the most charismatic and recognizable reef inhabitants.

Pufferfish (Tetraodontidae) are the chubby, clumsy helicopters of the reef. Unlike their spiky cousins (Porcupinefish), they have smooth or prickly skin without long visible spines. They are famous for their ability to inflate into a ball when threatened, turning a bite-sized snack into an unswallowable sphere. With their four fused teeth forming a powerful beak, they crunch through crabs and mollusks. While they look goofy and harmless, they carry one of the most potent neurotoxins on Earth— tetrodotoxin—making them a "look but don't touch" (and definitely don't eat) marvel.

Pygmy Seahorses are the tiniest gems of the ocean, often smaller than a fingernail. Unlike their larger cousins who swim freely, most pygmies spend their entire lives on a single gorgonian sea fan, matching its color and texture so perfectly that they become invisible to the naked eye. Discovered accidentally in 1969 when a scientist was examining a collected coral sample, these micro-masters of camouflage are the ultimate test for a diver's eyesight and patience.

The Sand Tiger Shark has the scariest smile in the ocean, but don't let its looks fool you. With a mouth full of jagged, needle-like teeth that protrude in all directions even when closed, it looks like a swimming nightmare. In reality, it is a docile, slow-moving giant that poses little threat to divers. Known as the "Grey Nurse Shark" in Australia and "Ragged-tooth Shark" in South Africa, it is famous for hovering motionlessly in currents—a skill it masters by gulping air into its stomach.

In the grand theater of the ocean, sardines play the role that seems unglamorous at first glance - they're small, silvery, and exist primarily to be eaten by everything else. But dismiss them as mere fish food, and you'll miss one of nature's most spectacular displays of collective survival. When billions of sardines migrate along South Africa's coast in the legendary "Sardine Run," they create a living river of silver stretching for kilometers, triggering the greatest feeding frenzy on Earth. For divers lucky enough to witness sardines forming defensive baitballs - spinning spheres of thousands of fish moving as one organism while sharks, dolphins, and seabirds attack from all sides - it's an unforgettable lesson in the power of coordination, sacrifice, and sheer overwhelming numbers.

At first glance, sea cucumbers might seem like the ocean's most uneventful residents - lumpy, slow-moving "sausages" scattered across the seafloor. But don't be fooled by their humble appearance! These echinoderms (cousins to starfish and sea urchins) are ecological superheroes, recycling nutrients by processing seafloor sediments. Even more fascinating, they've evolved one of nature's most bizarre defense mechanisms: when threatened, they can expel their internal organs and grow them back within weeks. For divers, encountering sea cucumbers offers a glimpse into the weird and wonderful world of regeneration, symbiosis, and survival strategies that seem straight out of science fiction.

Sea Lions are the underwater acrobats of the pinniped world—fast, agile, and endlessly curious. With their external ear flaps and ability to walk on land (unlike their seal cousins), they are the most social and interactive of the pinnipeds. They form large colonies, bark loudly, and are known for their playful behavior with divers. Encountering a sea lion underwater is like meeting an underwater puppy—they'll investigate your gear, play with your bubbles, and might even try to "show off" with acrobatic displays.

With their iconic five-armed silhouette, sea stars (commonly called starfish, though they're definitely not fish!) are among the ocean's most recognizable residents. But beneath that familiar exterior lies one of nature's most fascinating survivors - creatures that can regrow lost limbs, walk on hundreds of hydraulic feet, digest their prey outside their bodies, and in some cases, even reproduce by tearing themselves in half. For divers, sea stars are everywhere, from colorful reef decorations to slow-motion predators reshaping entire ecosystems. They're living proof that you don't need a brain to be brilliant at survival.

Sea urchins are the "hedgehogs" of the ocean, spiny, globular creatures that inhabit seabeds across the globe. With over 950 species, they come in a dazzling array of colors and sizes. While they might look like static pincushions, they are active grazers, slowly moving across reefs on hundreds of tiny, adhesive tube feet. They play a crucial role in marine ecosystems by keeping algae growth in check, maintaining the balance of coral reefs. However, their sharp spines demand respect from divers!

Seahorses are upright, slow-swimming syngnathiform fishes whose heads resemble a horse’s profile. They anchor with a prehensile tail, inhale prey with a snap of their long tubular snout, and wear interlocking bony plates instead of scales. Uniquely among fishes, males become pregnant: the female deposits eggs into the male’s brood pouch, where embryos develop until live birth.

Seals are the acrobats of the cold waters—graceful, curious, and surprisingly playful. With their streamlined bodies and powerful flippers, they are built for speed and agility underwater. Unlike their sea lion cousins, true seals (Phocidae) have no external ear flaps and move on land with an endearing belly-crawl. They are master divers, capable of reaching incredible depths and holding their breath for astonishing lengths of time. Encountering a seal underwater is like meeting an underwater dog—curious, intelligent, and often eager to interact.

Meet the ocean's most unlikely predator - a creature so stick-thin and bizarre it looks like a praying mantis crossed with a pipe cleaner and shrunk down to thumbnail size. Skeleton shrimp aren't actually shrimp at all, but amphipods that have evolved one of nature's most extreme body plans: they literally got rid of most of their middle sections, leaving just a thread-like body with grasping claws at one end and hooked feet at the other. Clinging to hydroids, seaweed, and sponges with their rear legs, they stand upright like tiny sentinels, their oversized front claws folded in a perfect "praying" position, waiting to snatch passing zooplankton. Some males even pack venomous punches in territorial cage matches. For macro photographers, skeleton shrimp present the ultimate "you've got to be kidding me" subject - translucent, microscopic, constantly swaying, and so perfectly camouflaged that even when you're looking directly at one, your brain insists it's just another strand of algae.

The Sperm Whale is the deep-diving champion of the ocean—the largest toothed predator on Earth and the deepest-diving mammal. With their massive, box-shaped head (one-third of their body length) filled with spermaceti oil, they are built for extreme depths. They can dive to 2,000+ meters and hold their breath for over an hour. They're also the loudest animals on Earth, producing clicks that can be heard hundreds of kilometers away. Encountering a sperm whale underwater is like meeting a living submarine— massive, mysterious, and perfectly adapted to the abyss.

If nature held a "most improbable body modification" contest, thresher sharks would be strong contenders with their tail that's literally as long as their entire body. That scythe-shaped caudal fin isn't just evolutionary extravagance - it's a devastating hunting weapon that these sharks wield like a medieval flail, whipping it at speeds exceeding 80 mph to stun entire schools of fish in a single strike. Despite this fearsome hunting ability, thresher sharks are among the ocean's gentlest giants, possessing tiny teeth and mouths so small they couldn't bite a human even if they wanted to (which they emphatically don't). For divers willing to make pre-dawn dives at specific locations like Malapascua Island in the Philippines, witnessing thresher sharks gliding gracefully through blue water, their impossibly long tails trailing like silk ribbons, represents one of diving's most elegant and privileged encounters.

The Tiger Shark is the ultimate opportunist of the ocean, second only to the Great White in size and reputation among predatory sharks. Named for the dark, tiger-like stripes that cover their bodies (especially juveniles), they are famous for their "eat anything" philosophy, earning them the nickname "Garbage Cans of the Sea." Despite their fearsome reputation, they are calculating and cautious predators, often cruising slowly through shallow coastal waters. Encountering a massive, striped Tiger Shark is an adrenaline-filled mix of awe and respect.

Triggerfish (Balistidae) are the "engineers" and "bouncers" of the reef. Named for their unique locking dorsal spine, they can wedge themselves into crevices so tightly that no predator can pull them out. While many species like the Picasso Triggerfish are painted living art, the family is infamous for the Titan Triggerfish—a highly territorial giant that fears nothing, not even divers. With powerful jaws designed to crush crabs and sea urchins, they are intelligent, industrious, and sometimes a bit too grumpy for their own good.

The Walrus is the Arctic's gentle giant—massive, whiskered, and equipped with the most impressive tusks in the marine world. With their long, ivory tusks (up to 1 meter) and 700 sensitive whiskers, they are perfectly adapted to life in the frozen north. They use their tusks as ice picks, social tools, and status symbols, while their whiskers act as underwater "fingers" to detect clams buried in the seafloor. Encountering a walrus underwater is rare and special—these are the true "tooth walkers" of the Arctic.

The Whale Shark is the undisputed giant of the ocean—the largest fish species alive today. Despite their colossal size (comparable to a school bus), they are the "Gentle Giants" of the sea, posing no threat to humans. These massive creatures are filter feeders, cruising the oceans with their cavernous mouths wide open to scoop up plankton and small fish. With a back covered in a constellation of white spots, swimming alongside one feels like drifting through a starry night sky.

The Whitetip Reef Shark is the quintessential reef resident—if you see a shark napping on the sand or under a ledge, it's probably this guy. Easily recognized by its slender body and white-tipped fins, it is one of the few requiem sharks that can stop swimming and rest on the bottom. While they look sleepy during the day, at night they transform into relentless hunters, using their flexible bodies to wiggle into tight coral crevices where other sharks can't reach. They are the "ferrets" of the shark world, rooting out prey from their hiding holes.

The Zebra Shark is the ocean's greatest transformers. Born with distinct black-and-white stripes (hence "Zebra"), they undergo a dramatic makeover as they mature, trading their stripes for leopard-like spots (hence the confusion with Leopard Sharks). With an extraordinarily long tail that takes up nearly half their total length and distinct ridges running down their body, they are unmistakable. These gentle, bottom-dwelling carpet sharks are docile "puppy dogs" that divers often find napping on the sand.