Barracuda

Slowly, slowly, he cruises
And slowly, slowly, he chooses
Which kind of fish he prefers to take this morning;
Then without warning
The Barracuda opens his jaws, teeth flashing,
And with a horrible, horrible grinding and gnashing,
Devours a hundred poor creatures and feels no remorse.
It's no wonder, of course,
That no little fish much likes the thing,
And indeed, it occasionally strikes the thing,
That he really ought, perhaps, to change his ways.
"But," (as he says with an evil grin)
"It's actually not my fault, you see:
I've nothing to do with the tragedy;
I open my mouth for a yawn and ah me!
They all swim in."

~John Gardner

The barracuda has a fearsome reputation, and no wonder, with its streamlined body that can reach lengths over six feet and speeds over thirty miles per hour, its large eyes that track even slight movements, a protruding lower jaw, and two rows of long, razor-sharp teeth. It's an efficient predator, found all across the globe in warm seas, with an absence only in the Eastern Pacific. The great barracuda, Sphyraena barracuda, is typical of the approximately twenty species of barracuda (but can be distinguished from the other species by black spots on its lower sides). Generally solitary, adult barracuda live predominately at or near the surface of deep reef habitats, though they are, occasionally, found at depths up to 325 feet. Juveniles mature amongst mangroves and seagrass beds, habitats that offer cover from predators, but once adults, they generally tend to avoid areas of brackish water. Coloration of the adult is brownish or bluish gray on the upper side with several dark bars (most often observable when the fish is resting over variegated substrate); the top shades to silvery sides and a white belly. This countershading is advantageous to a fish that swims near the surface of the water, camouflaging it from both predators and wary prey.

For much of its life, the great barracuda appears to disinterestedly float or coast among other fishes, periodically striking in a short, lighting flash. You would think most fish daren't come near, but like many other denizens of the deep, the barracuda shares a mutualistic relationship with a little fish known as the cleaner wrasse. The barracuda sits patiently in the water with its mouth partly open and its gills flared to allow the wrasse to eat off dead skin and parasites: a spa day for the 'cuda, a free meal for the wrasse.

Barracuda are voracious predators and generally hunt using a classic ambush style, relying on surprise and short bursts of speed to overrun their prey (not that they aren't capable of good ol' fashioned chase-'em-down style). Sight-oriented and generally diurnal, great barracuda locate their prey visually. They are piscivorous at all ages, feeding on array of fish including jacks, grunts, groupers, snappers, small tunas, mullets, killifishes, herrings, and anchovies. Even other barracuda are on the menu. As juveniles, these fish compete with needlefishes and small snapper for food. As they get older and bigger, they may compete with larger animals such as mackerel, or even dolphins, depending on their habitat.

That characteristic lower jaw is designed to quickly break the prey into bits, enabling barracudas to feed on large fish by chopping them up (Hello, Clarice). The needlelike teeth fit into their own holes in the opposing jaw, allowing the great barracuda to close its mouth, leaving no gaps. This means that once the barracuda has hold of a fish, there is no way for the fish to escape without leaving a part of itself behind. Even when a barracuda has eaten its fill, no fish is safe. Great barracudas have been observed herding schools of fish into shallow water. They will guard their livestock until their last meal has been digested and they're hungry again. Though juveniles fall prey to a variety of inshore predators, few predators are large enough or fast enough to feed on adult great barracuda. This exclusive group includes sharks, tuna, and goliath grouper, though even they are restricted to preying on small adult barracuda. Very occasionally, adults will school during the day, possibly for protection; groups of hundreds, even thousands, have been observed, but this is quite rare.

Based on scale analysis of large specimens, great barracuda have a lifespan of at least fourteen years. Sexual maturity is reached at a length of about twenty-three inches. At this size, males are typically about two years and females close to four years of age. The timing and location of spawning has not been well-documented. Some research reports that they spawn in the spring. Others claim that they spawn in association with particular phases of the moon. Still other research suggests that great barracudas spawn throughout the year, with the exception of cold winter months. Some report spawning in inshore waters; others believe it takes place in deeper, offshore waters. Perhaps great barracudas show different spawning patterns and locations in different areas of the world. Overall, the picture of timing and location is incomplete. What seems concrete is that great barracuda do not care for their fertilized eggs; they are left to drift in the ocean and be dispersed by currents. However they get there, larvae do tend to settle in shallow, vegetated areas of estuaries. Juveniles spend their first year of life within mangrove and seagrass habitats.

For those people who like to eat great barracudas, ciguatera is a concern. Ciguatera poisoning is caused by the bioaccumulation of ciguatoxins in the flesh of tropical marine fishes. Ciguatoxins are produced by the marine dinoflagellate species, Gambierdiscus toxicus, that grow on marine algae, and as such may be incidentally ingested by herbivorous fishes, so the highest concentration of toxins is found in the highest trophic levels, the large predatory reef-dwelling fishes occupying the apex of the food chain, namely barracuda. Ciguatera poisoning is a debilitating illness that results in gastrointestinal maladies that may last several days, a general weakness in the arms and legs, and a reversal in the ability to differentiate hot versus cold. The illness is serious (symptoms may persist for weeks), and sometimes deadly. Due to the danger of poison in barracuda meat, the Food and Drug Administration "requires seafood processors to conduct a hazard analysis of the potential food safety hazards that are reasonably likely to occur with the seafood products they process and to have and implement written Hazard Analysis Critical Control Point plans to control all hazards identified in the hazard analysis." Because of the health problems associated with ciguatera poisoning, barracudas have been used in research studies dealing with these toxins and have proved very effective in tracking and understanding ciguatoxins. Studies like these will allow us to more efficiently detect toxic areas and improve the treatment of ciguatera poisoning.

Although barracuda have formidable arrays of teeth, attacks on humans are rare. Inquisitive, visually stimulated fish, barracudas sometimes exhibit the unnerving habit of trailing snorkelers and divers, but more often than not, attacks occur because a barracuda attempts to steal a fish from spear fishers or mistakes a shiny object, such as a diving knife or jewelry, for the glint of a shiny fish. Such incidents usually consist of one very quick strike. Unfortunately, since their teeth are so sharp, even one strike can result in fairly serious lacerations.

So barracuda might not be prized as a commercial fish in Texas waters, and there may not be a Swim with Barracudas! attraction at SeaWorld, but the great barracuda puts up an excellent fight and is consequently esteemed by some anglers as a gamefish. The world's record on hook and line is a 5.5-foot, 103-pound great barracuda taken in the Bahamas. They tend to be lure-shy and can be difficult to induce to strike (seems ironic), but once hooked, barracuda provide swift runs and frequent leaps. What more could you ask for?


Where I learned about barracudas, and you can too!

Marine Bio
marinebio.org/species.asp?id=108

Florida Museum of Natural History
www.flmnh.ufl.edu/fish/Gallery/Descript/GreatBarracuda/GreatBarracuda.html

Gulf Fish Database
www.rodnreel.com/gulffish/gulffish.asp?cmd=view&FishID=2

Animal Diversity Web
animaldiversity.ummz.umich.edu/accounts/Sphyraena_barracuda/

BioWeb
Interactions: bioweb.uwlax.edu/bio203/s2008/sellnow_hann/Interactions.htm
Nutrition: bioweb.uwlax.edu/bio203/s2008/sellnow_hann/Nutrition2.htm

The Nature Conservancy
www.nature.org/newsfeatures/specialfeatures/animals/fish/giant-barracuda.xml

U.S. Food & Drug Administration
www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation/seafood/ucm375214.htm