Thumbnail sketches of the fishes you’re likely to see at dive destinations like Bonaire and Belize. Subjective and Caribbean-centric; not a comprehensive Fish I.D. Guide.
THIS POST (PART 3): RAYS TO WRASSES
LINKS TO PARTS 1 & 2:
RAYS – STINGRAYS, EAGLE RAYS, MANTA RAYS
With flattened bodies, rays have taken the pectoral fin/hydrodynamic lift concept so far as to develop their pectoral fins into broad “wings.” Eagle and manta rays’ wings let them soar through the open waters like…well, eagles…flapping and gliding. Stingrays have the same lift capabilities but spend much of their time close to or on the seafloor. They don’t swim high or far.
Rays are notable as the other cartilaginous fishes, along with sharks – that is, their skeletons are made of cartilage, lighter and more flexible than the calcium-based material of bony fishes (Hagfish and Lampreys are also cartilaginous; they’re not in my ouvre). Rays diverged from sharks some 300 million years ago.
There are more than 200 species of stingrays, about two-dozen species of Eagle Rays and only a handful of species of Mantas in tropical and temperate waters worldwide. And, of course, many other species in Order Rajiformes – Torpedo Rays, Cownose Rays, Butterfly Rays, Skates and other variations. I’ve included a few northern and Pacific cousins in the photo gallery.
On coral reefs in the Caribbean, the species you’re most likely to encounter are Southern Stingrays (Dasyatis americana), Yellow Stingrays (Urobatis jamaicensis), Spotted Eagle Rays (Aetobatus narinari) and, in the right places and with luck, Ocean Mantas (Manta birostris) and Reef Mantas (Manta alfredi). As usual, the Indo/Pacific basin counts a somewhat larger and more diverse population of Stingrays and Eagle Rays.
Each has their own approach to earning their livings. Eagle Rays and Stingrays scour the sandy bottoms to uncover the buried crustaceans, mollusks, worms, small fishes and other morsels that make up the bulk of their diets. Finding them, they use their powerful jaws to crush and grind up shells.
Stingray “wings” have developed to such an extent that they dominate the rays’ bodies, creating a somewhat diamond-shaped, slightly wedge-shaped at the head. Their mouths and gills are on their undersides. They their senses of smell, vision, hearing and electroreception to detect the presence of prey. Settled on the bottom, they flap their wings – their broad pectoral fins – to stir up the sand and uncover food (They also have lots of fishy friend who follow them around hoping for easy meals from the rays’ leavings).
Famously, Stringrays’ long, whip-like tails feature a slightly venomous stinger, largely a defensive weapon. Humans are likely to experience stings by accident, say by stepping on a ray. The injury can be painful but not usually life-thratening. “Crocodile Hunter” Steve Irwin’s death in 2006 was caused by an animal’s stinger penetrating heart, not by venom.
Stingrays often hide in the sand, covering themselves as a defense from potential predators. But sandy concealment also sets them to ambush a passing prey like small fishes. In such cases, they’re notable for a technique called “tenting.” As a prey approaches, the devious ray presses its broad fins against the bottom and raises its head, creating a suction that pull the unfortunate victim underneath its body.
With its eyes and spiracles all located on its upper side, our predator ray can’t see its victims after capture. But like sharks, they utilize smell and “ampullae of Lorenzini” to detect their prey’s electrical activity.
While swimming or in the open rays breath by drawing water past their gills through their mouths. Settled on the bottom and especially covered by sand, they can draw it in through their spiracles.
• Eagle Rays
Eagle Rays’ mouths and gills are also on their lower surfaces, but they have more of a snout design suitable for digging in the sediments. Swimming nearly constantly above the seabottom, they use those smale senses of smell, vision, hearing and electroreception to detect prey. They dig into the sand with their shovel-shaped snouts, unearth morsels copepods, crabs and little mollusks and crush them with hardened jaws.
Manta Rays are open ocean plankton feeders. Like Whale Sharks, they charge through the waters, mouths wide open, sweeping in crustaceans, small fishes anything in their way that may serve as food. Like Whale Sharks, they cruise almost constantly.
LENGTH: With Stingrays, width across their broad pectoral fins tends to be as notable as length. Southern Stingray width: Up to 7 feet, typically 4 or 5 feet. Length: 4 or 5 feet, with their tails as much as two times the length of the body. Yellow Stingrays are smaller, typically about 1 foot in length, not counting the tail, and 14 inches in disc width.
Eagle Rays: Typically scale in at 4 to 6 feet across; Manta Rays 20 feet, not counting the tails in either case.
Remoras at first consideration are lazy fishes that hitchhike rides around the oceans by attaching themselves to bigger animals and letting them do the heavy work of actually moving. Meanwhile, the Remoras feed off the food scraps that their hosts scatter about while attacking their prey.
They attach themselves to sharks, whales, turtles, even parrotfish with dorsal fins they’ve evolved into suction pads. Which means, they basically ride the world and see the world upside down. Lacking gas bladders, they are poor distance swimmers with poor buoyancy control, so hitching to fast swimmers is a way to compensate for poor swimming abilities, poor buoyancy control and poor foraging skills. Theoretically, they don’t harm their hosts, although the possibly annoy them.
There are eight species found worldwide, some host-specific. A name you will hear mentioned my be “Sharksucker,” although I’ve seen Sharksuckers on Parrotfish and other marine animals. I’ve even seen one do its best to adhere itself to a diver’s leg.
LENGTH: Sharksuckers: Typically 10 to 18 inches, Common Remoras and White Suckerfish Remoras : typically 12 to 15 inches.
Scorpionfish are well-camouflaged guys who lie in wait on the substrate ready to strike unfortunate passers-by with lightning speed. Fleshy cirri, or flap-like appendages matching the background, may cover their bodies to help them blend in with their surroundings. Which, of course, makes them harder to identify.
They’re Scorpionfish because they have spines on their body covered with painful, possibly deadly, mucus toxins. The spines are defensive but since the scorpions are so well disguised, it’s possible to accidently come in contact with a lying-in-wait fish. The toxins of Atlantic/Caribbean Scorpions are said to be significantly painful but less life-threatening than with their Indo-Pacific cousins.
It’s estimated that there are between 200 and 400 species in Family Scorpaenidae worldwide, only a handful in the Caribbean. As the gallery below suggests, however, the appearance of Scorpions of the same species can vary significantly as they blend into their habitat.
LENGTH: Spotted Scorpionfish: Typically 12 to 14 inches; Reef Scorpionfish: 2 to 5 inches.
Seahorses are at once weird and wonderful and unique among bony fishes. Underneath their obvious horsey-head charm, seahorse anatomy is really, really different from other fishes. If searching for them carries an air of anticipation, finding them is like watching grass grow. When spotted, they’re likely to just be hanging out attached to a sea rod with their prehensile tails.
They’re terrible swimmers, as seen in two of the shots below, but super-predators of tiny shrimps and other planktonic delectables. Their bony bodies mean they have few predators of their own. Their lack of teeth and a stomach mean they have to continuously eat to survive. As seen with the Loongsnouts in the gallery, their colors may vary to blend into their surroundings.
Found in oceans worldwide in some 44 species, they range from rice-grain size to foot-long giants (most species are more likely to be in the three- to five-inch range). They’re largely monogamous and may be best known for the fact that the male does the childbearing.
LENGTH: Most species of Seahorses, like the Longsnout Seahorses pictured here, are in the 2.5 to 5 inch range.
Sharks encompass some 400 species of sharks worldwide, and only a relative handful are the dangerous predatory beasts of cable television. And those sharks are largely open-water animals; you’re unlikely to encounter them on tropical reefs.
The sharks you will see are generally guys like Reef Sharks, Blacktip Sharks, Gray Reef Sharks and Nurse Sharks. They have teeth and are formidable in their own right. You’d want to keep your distance and your hands to yourself but they’re unlikely to bother you. Unless you’re stupid. A couple years ago a woman in Australia was injured, not seriously, by a Nurse Shark, one of the most docile of species – because she insisted on hand-feeding it.
If you go to the right places, you may be blessed by seeing a Whale Shark. And everybody wants to see Hammerhead Sharks but you’re unlikely to see them on most resort-reef visits, unless you go to specific sites specializing in them, like Bimini, Costa Rico’s Cocos Island, the Galapagos or Maldives.
LENGTH: Reef, Blacktip and Nurse Sharks: typically 5 to 9 feet. Whale Sharks: more than 50 feet; Great Whites: up to 20 feet; Scalloped Hammerheads: up to 14 feet.
Snappers, as in Gray, Yellowtail and Schoolmaster Snappers and other members of Family Lutjanidae, are relatives of grunts without the colorful stripes. They’re generally some variation of silvery in color and larger – seven to 10 inches to as much as 2½ feet in length. They tend to be nocturnal, feeding in the sandflats and seagrasses on small fish and cephalopods, crabs, shrimps and worms.
Their daytime social habits vary: Gray Snapper (Lutjanus griseus) are likely to be found hanging in small, sometimes closely packed groups in protected areas. I’ve most often seen Schoolmasters (L. apodus) hanging out alone underneath rope sponges, inside the branches of sea plumes or just plain hovering above barrel sponges.
Yellowtail Snappers (Ocyurus chrysurus) are more likely to be solitary; if they belong to groups, they’re pretty loosely formed. They’re brazen about mooching food. I had one sneak up behind me and try to pull something it thought was food (it wasn’t) from the pocket of my swim trunks once.
Glasseye Snappers aren’t snappers at all; they just use the “snapper” name as a nom de plume. They’re really part of the Bigeye family, Family Priacanthidae.
LENGTH: Yellowtail Snappers and Mutton Snappers: Typically 1 to 2 feet; Snappers: 1.5 to 2.5 feet; Gray Snappers and Schoolmasters:10 to 18 inches.
SQUIRRELFISH, SOLDIERFISH, BIGEYES
Squirrelfish, Soldierfish, Cardinalfish and Bigeyes are all bright red fishes that forage on the bottom in the night and are generally found hiding under ledges, rope sponges and other forms of cover during the day.
Since red fades to dark as natural light diminishes, their reddish colorations are advantageous for nocturnal scroungers, and their large eyes aid them in low light situations. Squirrelfish are sometimes seen in the open during the day. the
Big Eyes are normally denizens of deeper depths. Generally, they hunt out small crabs, shrimps, copepods and mollusks.
LENGTH: Bigeyes, 8 to 12 inches. Blackbar Soldierfish: 4 to 8 inches. Squirrelfish species vary: Reef Squirrelfish only to 5 inches, Longjow Squirrelfish to 7 inches, Longspine Squirrelfish to 10 inches.
Family Acanthuridae encompasses more than 80 species, most exotic in appearance and most located in the Indo/Pacific. But three are found in the Tropical Atlantic/Caribbean basin – Ocean Surgeonfish (Acanthuridae tractus), Doctorfish (Acanthuridae chirurgus) and Blue Tang (Acanthuridae coeruleus). They’re all more-or-less a foot in length.
They’re all herbivores, specializing in, and credited with, helping keep living corals free of algae that might otherwise overgrow and suffocate it.
Adult Blue Tangs may be the most familiar, since mobs of them are frequently seen rushing around the reef grabbling bites of algae here and there and moving rapidly on. Normally, safety in numbers is considered a defensive behavior, but in this case the mob approach helps them overwhelm the territorial protectiveness of the damselfish whose little algae farms they’re raiding.
Blue Tangs actually have three color phases: As juveniles as they are bright yellow, as intermediates a pale to dark blue with a yellow tail, and the deep blue (with blue tail) adult phase. Actually, as adults the blue can vary significantly from deep to pale to bluish gray and near brown. Adults typically display a small, dart-shaped yellow spot at the base of the tail.
Ocean Surgeonfish have slightly more elongated bodies than the roundish Blue Tangs. Adults also tend to have bodies that vary between bluish gray and dark brown, but sometimes so pale as to appear white. A constant is blue or white edging on their dorsal and tail fins.
Doctorfish are very similar to surgeonfish in shape, fins and colors. What defines a Doctorfish is a series of 10 or more dark vertical bars along each side of its body. Ocean Surgeonfish never have these.
LENGTH: Blue Tang: 5 to 10 inches, maximum 15.5; Ocean Surgeonfish and Doctorfish: 6 to 12 inches, maximum 15.5.
Triggerfish are close cousins to filefish, with stouter front dorsal spines that resemble “triggers,” which they can erect when endangered They encompass about 40 species worldwide. They tend to have narrow, oval-shaped bodies. In the Caribbean region, three species you’re most likely to encounter are the beautiful Queen Triggerfish (Balistes vetula), the Ocean Triggerfish (Canthidermis sufflamen) and the Black Durgon (Melichthys niger). Most of the time, you’re unlikely to see the triggers erected.
• Queen Triggerfish (Balistes vetula), typically about a foot in length and ornate with color and patterns, use “trigger” spines on their front dorsal fins to make being swallowed by predators difficult. And, they use their triggers to wedge itself into crevices at night to hinder being pulled out by predators. They’re daylight feeders, specializing in invertebrates like clams, crabs and shrimp, starfish, sea cucumbers and worms. They famously prey on sea urchins by puffing water to overturn them to get at their vulnerable undersides.
• Ocean Triggerfish (Canthidermis sufflamen) are the ones of the three species you’re likely to encounter the least – they tend to be loners and prefer open water above and away from the reef. Also, they’re shy. But they do show up. They reach lengths of as much as 18 inches.
• Black Durgons (Melichthys niger) are the Triggerfish you’re most likely to encounter – they tend to stick together in groups and are simply more abundant. Mid-water planktivores, they’re hard to photograph. As they swim around in mid-water, they generally appear totally black with light blue lines running along its dorsal and anal fins.
Up close they reveal blue/green and orange coloration around their heads. They’re wriggly and their blackness soaks up light and detail. They create egg nests in crevices and seafloor depressions and tend to hang around guarding them for a period. Which how I’ve managed to get decent photos.
LENGTH: Queen Triggerfish: 8 inches to 2 feet; Ocean Triggerfish: 10 inches to 2 feet; Black Durgons: 6 to 16 inches.
Trumpetfish (Aulostomus maculatus) seem to spend most of their day just swaying along with the surge, hovering head-down in crowded places like rope sponges and sea plumes. But they’re pretty nearly always on the hunt while seeming to be doing nothing. They’re an anomaly among piscivores – they hunt throughout the day, mostly pointing down, ready to strike at fishy prey below.
They rely on vacuum feeding big time: They have virtually no teeth. Their base-line prey includes shrimps, copepods and small fishes like gobies, blennies and chromis but they do prey on larger fishes.
They appear in varying colors but they’re all members of a single species. Most commonly, A. maculatus displays a mottled, reddish brown color, with silver or bluish streaks and black or brown spots along their bodies. But it’s not unusual to see bright yellow, blue-gray or green specimens. They’re all the same species. And they’re experts at camouflage, with an ability to lighten or darken their colors and manipulate silver and blue streaks along their bodies and black bars or spots on their fins. They can grow up to three feet in length.
They’re closely related to seahorses and pipefish, and they share those species’ trait of the males holding onto and hatching the eggs that produce new, little fishes. Trumpetfish do have closer cousins in the form of cornetfishes, less-common denizens of the tropical Atlantic & Caribbean, and “Chinese trumpetfish,” found in the Indo-Pacific basin.
Often, trumpetfishes engage in “shadow feeding,” disguising their presence by swimming with herbaceous animals like princess parrotfishes, ready to strike any prey of opportunity. While trumpetfishes’ small fins don’t make them great long-distance swimmers, they can coil their bodies above their proxies and strike quickly.
At night, trumpetfish tend to sleep in a vertical position, often lining themselves up with upright structures like sponges and gorgonians – and pier pilings.
LENGTH: Typically 1.5 to 2.5 feet, up to 3 feet.
Trunkfish are members of Family Ostracomis, the Boxfish family that also includes cowfish. There are some two dozen species found in the oceans worldwide. In the Atlantic/Caribbean the two most prevalent species of trunkfishes, and the ones you’re most likey to encounter, are the Smooth Trunkfishes (Lactophrys triqueter) and Spotted Trunkfishes (L. bicaudalis). Close cousins you’ll see around are Honeycomb Cowfishes (Acanthostrac polygonia) and Scrawled Cowfishes (A. quadricomis).
All sport flattened undersides that reinforce their angular architecture, shaped somewhat like Soap Box Derby entries. Trunkfishes at their best are relatively inept swimmers, with bulky, triangular bodies and limited tailfin propulsion. They row furiously, they move slowly and awkwardly (Juveniles, which lack tails, are aboth endearing and absurd to watch try to swim). Fortunately, their boxy architecture reflects a series of fused subdermal plates, providing them with serious protection from predators.
Smooth Trunkfish tend to run 6 to 10 inches in length, Spotted Trunkfish slightly longer. Cowfish run to as long as 15 inches.
The mouths of all Ostracoms share two characteristics: powerful jaws, the kind used to crack the shells of mollusks and crustaceans, and protruding lips that look like they’ve been over-blasted with botox. Presumably, those lips facilitate their technique of blowing away bottom sediment with a jet of water to expose the prey that make their diet – worms and the aforementioned mollusks and crustaceans. They’ve also been known to bite off pieces of coral to get at polyps and to expose underlying prey.
In reality, they’re omnivores, which means they’re also known to feed on sponges, tunicates, sea cucumbers and sea urchins and to graze on algae and sea plants.
LENGTH: Smooth and Spotted Trunkfish: Typically 6 to 12 inches. Honeycomb Cowfish: 7 to 18 inches.
Wrasses are among the most commonly seen fishes on the reef – so common that they’re likely to be taken for granted. And, in fact, the bulk of them seem to be Bluehead Wrasses, except that most of the ones you see are small, yellow juveniles who seem to be everywhere. There are some 600 species of wrasses worldwide but at one point naturalists thought there were many more due to the succession of phases and color patterns they went through. As usual, most of them are found in the Indo-Pacific basin.
In the Atlantic/Caribbean, the count is more like a dozen; the most familiar are Bluehead Wrasses (Thalassoma bifasciatum), Yellowhead Wrasses (Helichoeres gamoti), Slippery Dicks (Helichoeres bivattatus), and Creole Wrasses (Clepticus parrae).
Among Blueheads, Yellowheads and Clowns, you’re much more likely to many more juveniles than adults. Juvenile Bluehead Wrasses appear to be among the most common and ubuquitous fishes on the reefs (and also the most studied by researchers). The challenge with wrasses is that they go through so many phases – changing colors, stripe patterns and the like) that it’s hard to adquately describe all the possibilities.
Adult Blueheads and Yellowheads are invertebrate carnivores, capturing small mollusks and crustaceans from the seafloor. Juveniles are prominent cleaners, darting around picking off parasites and dead scales off larger fishes. But they’re also notorious egg thieves, known for raiding damselfish egg nests. Adult Blueheads sometimes take part in the raids.
Creole Wrasses are planktivores, often seen swimming in great columns above the reef picking zooplankton out of the currents. They mostly come off as indigo blue, but with pinkish and yellows frequently appearing.
LENGTH: Adult Bluehead Wrasses: Up to six inches, juveniles typically 1.5 to 3 inches; Adult Yellowhead Wrasses: Up to eight inches; Slippery Dicks: Up to seven inches; Creole Wrasses: Typically 4-7 inches.
PRINCIPAL SOURCES: Reef Fish Identification Florida, Caribbean, Bahamas, Paul Humann, Ned DeLoach; Reef Fish Identification, Tropical Pacific, Gerald Allen, Roger Steene, Paul Humann, Ned DeLoach; Marine Life, Caribbean, Bahamas, Florida, Marty Snyderman & Clay Wiseman; Reef Fish Behavior, Ned DeLoach; Peterson’s Field Guide to Atlantic Coast Fishes, C. Richard Robins, G. Carlton Ray, John Douglass; Discover Fishes, Florida Museum of Natural History; Marine Species Identification Portal; Assorted Fish Species Topics, Wikipedia, Encyclopedia Britannica.