Cozumel Marine Life – Camouflage Critters

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I just learned a new term while researching this post: cryptic coloration

That’s another way to say “camouflage” which I – like many divers – find endlessly fascinating. 

Especially when you see it truly in the flesh, while scuba diving in Cozumel, or in another high-quality scuba diving destination. 

As a diver, you can witness lots of examples of cryptic coloration among marine life, especially coral reef dwellers and fish or invertebrates that inhabit the ocean’s sandy floor. 

Cryptic Coloration Underwater

Camouflage can be used by many different types of organisms including birds, reptiles, amphibians, insects, and even mammals, like the sea otter. 

Underwater, many of the biodiverse species living in or near coral reefs also use adaptive camouflage for survival.  

Common marine animals that have cryptic coloration include fish, crustaceans, mollusks, echinoderms, and cephalopods like the awesome octopus. 

Marine biologists have studied how these creatures are able to disguise themselves in order to avoid being seen – and eaten – by other species.

Changing color can also be used among underwater animals as a means of communication, as in when a large fish or shark is ready to be cleaned by a smaller fish. The barracuda, for example, may alter its color to indicate it will not harm various small cleaner fish or shrimp during that time. 

Some marine animals may change color when ready to attract a mate, or when on a different kind of hunt – for prey.

Camouflage Critters in Cozumel 

The various means of camouflage by marine animals are some of my favorite phenomena to witness and photograph when scuba diving in Cozumel – or anywhere, for that matter.

Here are a handful of common Caribbean marine species that rely on cryptic coloration to survive, so be on the lookout for these animals when you’re scuba diving in Cozumel

Read on for a primer on best examples of camouflaged Cozumel marine species:

Octopus

Probably the most celebrated underwater creature with an incredible set of camouflaging abilities is the octopus, a cephalopod. 

When diving in Cozumel, we mainly see the Caribbean reef octopus (Octopus briareus), and typically only at night, during one of our awesome night dives. 

However, you can get lucky and spot a Caribbean octopus out on the reef during the day on any one of the dive sites, or at least hiding in various cracks and crevasses. 

Cozumel octopi frequently live inside hiding spots in coral reefs where they feed on small invertebrates like crabs, shrimp, worms, jellyfish, etc. Octopuses also eat mollusks, like scallops, clams, and snails.

Cephalopod skin has an amazing ability to change colors quickly, thanks to cells called chromatophores.

Many thousands of color-changing cells called chromatophores just below the surface of the skin are responsible for these remarkable transformations. The center of each chromatophore contains an elastic sac full of pigment, rather like a tiny balloon, which may be colored black, brown, orange, red or yellow.

Smithsonian Institute’s Ocean Life website

Not only are their cryptic coloration skills amazing to see in real-time, but they also have the added abilities of shape-shifting, and sometimes can even mimic the textures, carriage, and behaviors of their backgrounds and other species. 

When diving in Cozumel, you can watch an octopus moving across the coral reef, and witness its colors morph into the surrounding rocks and coral, and it essentially disappears into its environment, before your very eyes.  

The most common time to see octopus here is after the sun goes down, namely when diving at night

On Cozumel night dives, using artificial lights to see the animals’ skin color (when it is calm and not in fight or flight mode), divers can witness the brilliant aqua blue-green color of our most common local octopus population.

There is always a chance to see them during the day, as well, though that’s when they are typically hiding.  

Caribbean reef octopus out blending in with sand, rocks and coral reef

Even if they’re not hiding in a cave or fully blended with the reef, they still blend in quite well most of the time and easily use their cryptic coloring to meld with the surrounding rocks and corals. 

OR they might just try to grab the first hiding spot they can, like this funny little guy I recently found hiding in a nice round sponge, suspended off the side of the reef at about 45 feet. It wasn’t such a quality hiding place, but I almost missed him!

Small reef octopus hiding in hollowed out sponge.

Scorpionfish

The scorpionfish is another favorite among Cozumel’s cool marine animals that does a great job of blending into its surroundings.  

Often you will pass by a scorpionfish embedded in among coral heads, rocks, or even seagrass, and not notice it until you get closer – or indeed pass it by in the current. 

Scorpionfish blending in with multicolored coral background.
Scorpionfish

The scorpionfish will often look similar to a rock covered in algae. Thanks to its largely sedentary behavior as a cryptically colored ambush predator, a scorpionfish may in fact allow algae to grow on itself, creating a deceptively welcoming place for small fish and other organisms to seek shelter. 

Scorpionfish then use their large jaws to open extremely quickly – mere milliseconds – creating a strong vacuum effect that sucks in its targeted prey into its mouth in a flash. 

When the scorpionfish itself feels threatened, it may use another related tool of coloration by suddenly opening and “flashing” the skin inside its fins to display a much more flamboyant set of colors and spots.  This flash of color warns predators that the scorpionfish has the capacity to deliver a venomous sting with its dorsal spines.

Regarding scorpionfish and human scuba divers, not seeing one could potentially be dangerous. 

Human injuries are rare, but sometimes divers or snorkelers may accidentally step on or otherwise brush up against a camouflaging scorpionfish, which causes the fish to strike with its venom-filled spines – very similar to a lionfish puncture wound and sting, combo. Youch.  

When diving in Cozumel, try to avoid this at all costs – for both of your sakes. 

According to Divers Alert Network’s (DAN) handbook on hazardous marine life, this process is called “envenomation.” Scorpionfish venom could cause serious complications and should be treated and monitored, but most often the result is a small but nasty wound, accompanied by great stinging pain for several hours, swelling for a day or two, and probably bruising for a few days. 

Peacock Flounders

Flounders are another common group of Cozumel bottom-dwelling fish that utilize color changes to survive. 

Peacock flounders are the main type, and when diving in Cozumel you can see a range of them, from teeny juvenile flounders in the sand, up to large ones that are resting in seagrass beds, on the coral reef itself, or using their sandy-colored cryptic coloration to mimic the sandy ocean floor. 

It’s often difficult to spot these fish at first because of their natural camouflage.

Flounders on the ocean floor – especially the juveniles of the species – are almost invisible against the sand, and sometimes the best way you find them is if you happened to catch one moving out of the corner of your eye. 

Tiny juvenile flounder blending in with sand in Cozumel.

It doesn’t help that the very young juvenile flounder are tiny – in the case above, for example, only about a half-inch / 2cm in length. 

But once you start getting the hang of spotting Cozumel’s flounder fish, you might catch sight of one quicking darting along the sand, or notice a break in the sand pattern, only to recognize the fish’s eyes or the notched edges of its dorsal, anal and pelvic fins. 

Trumpetfish

Trumpetfish are fun and frequent fish to see while diving in Cozumel, and while I always seemed to see them around long fronds of sea whips or gorgonian corals, I didn’t quite get that they were camouflaging at first.

According to Lamar University’s marine biology department profile of trumpetfish, this tendency to hide and hover among corals is due to them being poor swimmers.

This allows them to hide from potential predators, and also gives them more of a chance to find a good snack.

Trumpetfish hiding in and mimicking gorgonian coral in Cozumel.

Trumpetfish have pigment-filled chromatophore cells (like the octopus’ mentioned above) so they change color to blend in with a particular scenery they’re in. Trumpetfish also use mimicry behavior to look like the coral or other structures they hide in (as seen in the image, above).

Juvenile Filefish

Adult filefish are large, with unique long tail fins, and a distinctive shape.  

As juveniles, however, filefish are not only very small, but they’re great at blending in with their surroundings – typically various types of gorgonian corals. 

The juvenile filefish are tiny little fish and tend to stay hidden within the branches of the corals on the reef, which makes them even harder to spot. 

In addition, juvenile filefish mimic the colors and textures of the coral they’re inhabiting, so they blend in skillfully – to the point of almost vanishing. 

Juvenile filefish blending with purple coral in Cozumel.
The only purple one I’ve seen so far – because of its background, I think!

However, sometimes if you spot one and can maintain good buoyancy control and stay still, you’ll notice them drifting about between the arms of the coral, only to “disappear” again. 

This behavior helps keep them safe from larger predatory fish…and often from the prying eyes of underwater photographers. 

Juvenile filefish were some of my favorite first underwater macro subjects, despite the initial challenge of spotting them, and then the now ongoing challenge of capturing a nice frame while they seem nonchalantly intent on ducking away and behind the thin branches of a gorgonian coral. 

Juvenile filefish in beige soft coral in Cozumel.

Stingrays

Stingrays seem to use a combination of hiding and blending techniques. 

Like sharks, larger southern stingrays seem to be a good example of the type of camouflage known as countershading.  Here the ray is dark on the top, so less detectable to predators (or fishermen) from above, while very light on their underside, so bottom-dwelling animals don’t see them coming, as from below they blend into the brightness of the ocean’s surface. 

Stingrays also use a simple hiding technique, where they flap their ‘wings’ (a.k.a. pectoral fins) and nestle down into the sand, nearly covering themselves with a thin layer of top sand.  

Sometimes, all you can spot are their eyes or spiracles (breath holes) – or from a wider view, the full outline of their impressive size and shape. 

large southern stingray hiding under thin layer of sand in Cozumel

Meanwhile, Cozumel divers will also encounter numerous small yellow stingrays. 

Yellow stingrays are only about 1 foot/30cm long and have more elaborate markings, which often make them stand out. 

But when you see where they tend to seek shelter or rest, it becomes obvious that those markings actually aid in their need to blend. 

Yellow stingray blending in perfectly with beige and ivory sandy surroundings.
Yellow stingray

When resting, small yellow stingrays spread their bodies flat on the sandy seabed, sometimes even going farther and burrowing themselves under a light layer of sand to truly cover their bodies. 

There have been many times when I was looking at some other marine critter nearby, only to swim right over a stingray that was buried in the sand.  Yikes. 

Divers should please always be mindful of the many sand-dwelling critters, to avoid that kind of accidental confrontation and more importantly, to respect the full marine habitat, and not disturb the thousands of sand-dwelling critters, large and small. 

Lizardfish, a.k.a. Sanddiver

This is a funny little fish that blends in well with its environment. 

The lizardfish has an elongated body, and looks very much like a lizard swimming through the seagrasses, and then stopping for prolonged periods to seemingly ‘lay out’ on a sunny rock for a while – much like a local Cozumel gecko or iguana. 

Lizardfish "sunning itself" like a Cozumel iguana.

They don’t really seem to do anything else except sit there quietly until someone or something disturbs them. 

Then they quickly dart away, leaving just enough time for you to realize what happened before they disappear completely. 

From time to time, though, they exhibit an excellent form of marine camouflage. 

Also known as sanddivers, lizardfish will bury themselves in the sand, leaving only their face exposed. 

Sanddiver with just its face emerging out of the deep sandy ocean bottom.
Lizardfish – a.k.a. Sanddiver

Lizardfish are not dangerous, but when you’re not expecting something hiding under the sand like that – and then get to experience their super quick, darting action when approached too closely – it can really startle you.

Nurse Sharks 

Like their stingray cousins, above, nurse sharks have natural countershading. This makes them obscured from sight from above, as their darker backs and dorsal fins blend in with the ocean depths and meanwhile are less noticeable to low or bottom-dwelling prey.

Then again, most of the time, nurse sharks in Cozumel are good at just plain hiding under the reef for a daytime nap.  

To read and see more about shark encounters in Cozumel, check out this full post on the types of sharks divers often see in Cozumel. 

Sea turtles

Turtles are reptiles, a class of animals known for great camouflaging techniques.

When you see a sea turtle in the sand, it’s not immediately obvious that they are indeed working the cryptic coloration.  

However, when you see them swimming and feeding among the corals or in grassy areas, you can understand how their coloring provides them with better camo coverage, so they may elude larger predators. 

Juvenile hawksbill turtle in Cozumel blending in to background.
Can you spot the young hawksbill turtle?

To read all about the island’s local sea turtle populations of loggerhead, hawksbill, and green sea turtles, and where to see them (and help them!), please go next to our full guide to Cozumel sea turtles, here. 


So, there you have it.  If you’re into marine biology and camouflage, you’ll very likely see the above examples, and more, if you’re scuba diving or snorkeling in Cozumel.  

And if you want to get into taking some fun specimen photos like the ones in this article, check out my recommendations for high-quality but simple and inexpensive underwater camera gear, just below.

This relatively inexpensive and easy setup will help you pack light, yet get you going on the right path with underwater photography. It also can grow with you as you get more advanced, and keep you taking terrific, framable dive trip photos for years to come.

CozInfo’s Recommended UW Camera Gear

If you want to get started with underwater photography but aren’t sure what to buy, this setup is easy and inexpensive, gets great technical reviews all over the internet, and is used by thousands of divers all over the world.

It’s also light, and can easily fit in your carry-on bag – a big consideration these days.   

This straightforward kit is accessible and simple when you’re just starting out, but it can grow with you as you progress in your new hobby. 

This is the exact UW camera gear I use on every dive and for all the UW images on this site.

My Tried and True Dive Photography Kit: 

  • Olympus TG-6 compact camera
    Olympus’ “tough” series is inherently waterproof and dust/dirt proof, so it’s also great for other outdoor activities, or as your everyday point-and-shoot camera for weddings and events.  Small and durable. 
  • Olympus PT-059 Marine Housing. 
    Olympus’ own marine housing allows the camera’s on-board flash to operate without additional cables or added strobes. This is important if you don’t want to deal with external strobes, etc.  The marine housing is needed for diving, but not for snorkeling or swimming depths. 
  • 64GB Memory Card. 
    I’ve used this exact card for years, and it hasn’t failed.  I bought a backup, but haven’t needed it, yet. 
  • Memory Card Reader. 
    I find this memory card reader a dead-simple way to save my photos to my MacbookPro at the end of each dive day.  I don’t want to rely on wifi during dive trips, and while I’m using the card in the card reader, I can be recharging my camera for the next day.  
  • Camera lanyard!!!!! 
    I’m not kidding – if I had a dollar for every time someone posted on social media about losing a camera on one of Cozumel’s dive sites, I’d have…hundreds of dollars.  Plus, I’ve lost my own camera and housing…TWICE!  Lesson (finally) learned.  Now I never go in without this simple coiled lanyard clip that attaches to a D-ring on my Cressi BCD, and give me plenty of range of motion, yet the security of knowing I won’t throw another camera and housing down the drain.   The best 20 bucks you’ll spend on this hobby. 

    *These are my honest opinions on products I use every day. The links above are affiliate links, where I may receive a commission on referred visits and purchases at no extra cost to you.

Rachel

Rachel runs and writes CozInfo.com when she's not diving, taking underwater photos, or trying a new local restaurant. After decades of project managing some mighty fine exhibition design projects in NYC, she took an adult gap year to pursue her divemaster training in Cozumel...and never made it back.