By Scotty Kyle
I am a Mahi Mahi. Fishermen call me Mahi Mahi, Dolphinfish, or Dorado, while scientists refer to me as Coryphaena hippurus. To recreational anglers, I am a prized catch that “ticks all the boxes”. The Hawaiians named me Mahi Mahi, which means “strong strong,” and reflects my resilience and power, especially since I am not a fan of being caught and often not released.
I feed aggressively, often smashing into bait or lure. Once hooked, I put up a fierce fight, pulling line powerfully, ducking, diving, and leaping high out of the water, vigorously shaking my head to dislodge the hook. I am strong, athletic, and acrobatic, and I try everything to avoid being “boated”. Once aboard, I can thrash violently in a bid to escape or inadvertently injure someone. My hydrodynamic shape allows swift, effortless movement through water, reaching speeds over 50 human knots (57 mph) over short distances. Anyone wanting to catch one of us must be prepared for an intense struggle, where one can’t afford to make a single mistake nor lose concentration for a second – or we will be gone forever.
Many consider us among the most beautiful fish, with our unique shape and vibrant, almost indescribable colors. Humans describe us as “strongly laterally compressed”, meaning we are thin, with large heads and relatively small mouths. We belong to the few species of fish that display clear sexual dimorphism; while the our females are elegant, thin and relatively delicate, the males are different. With age, we develop a protruding forehead with age, which is quite attractive to our females, leading to multiple, frequent spawning sessions. Our living colors are bright, metallic yellows, blues, greens, and gold, translucent, shimmering, dazzling and spectacular, but they quickly fade after death.
I hatched from an egg floating in the upper layer of the Mozambique Channel, drifting southwards off mainland Mozambique and then South Africa. I quickly found some floating debris and adopted this cover as my home for a few weeks. Growing rapidly, possibly faster than any other fish species, I initially fed on plankton, soon progressing to fish larvae and crustaceans. My species is active, almost never stopping, and, when possible, we will spend much of our time actively feeding, leading us to reach a mass of 20 kg (44 lbs) in our first year. We mature at 4-5 months and spawn every 2-3 days under suitable conditions. Add to this our females producing 33,000 – 66,000 eggs per session, and you have a fish species unsurpassed in potential to reproduce and grow under ideal conditions.
Our lifespan, however, is relatively short, and we rarely see our fifth birthday. The largest recorded mass was 40 kg (88 lbs), but such large specimens are now rare due to fishing pressure and predation. Nowadays, most of us caught weigh between 7-13 kg (15-29 lbs). Our rapid growth and prolific spawning make us ideal for aquaculture. From the ethical point of view, it’s not the best idea to confine such aggressive, social and active species like us to cages or ponds. However, if it reduces pressure on wild populations, it could benefit us overall.
After a few weeks of hiding under floating debris, I overgrew my cover, discovered a few more of my species, and joined a shoal. We spent most of our time in the upper layers of the ocean, continuously hunting for our favourite foods – small shoaling fish such as pilchards and young tuna, as well as squid. One of our favourite foods is flying fish; we enjoy chasing them until they shoot out of the water, and then anticipating where they will land. We feed throughout the day and sometimes after sunset, particularly under a full moon, pausing only when it’s too dark or too hot.
Our attraction to floating debris can be our downfall. Any natural or man-made object, such as floating weed, logs, debris or even aggregated plastic, will attract us and make us vulnerable to anglers. For example, in the Sargasso Sea, as pieces of floating weed break free from larger masses, there are often a few of us under each piece, and fishers simply move from weed patch to weed patch casting towards them and catching us. Some unscrupulous people set out Fish Aggregating Devices (FADs), which can be very sophisticated. For example, in Marine Protected Areas (MPA’s), where it’s illegal to place them, FADs can be anchored under the ocean surface.
Apart from humans, we have relatively few real enemies due to our amazing speed and manoeuvrability. We are generally far too fast for slow, cumbersome sharks, and only marlin, swordfish and sailfish can really match our tempo and agility.
Our species is found globally in tropical and temperate areas. We are particularly common in the south-eastern seaboard of the USA around places such as Florida and in the Gulf of Mexico. We are also targeted throughout the Caribbean Sea and southwards past Brazil, as well as off the east coast of Africa. In all these areas, as well as off much of the coast of Australia, sport anglers can hire charter boats and crews to target my species. And also commercial fishing operations pursue us across our distribution range, especially in Asia, catching, killing, freezing and selling as many as they can.
We do not have a clear spawning migration, but we do undertake predictable annual movements, and knowledge of these is essential for success in catching us. We tend to move to more temperate areas in summer, that is, northwards in the northern hemisphere June to August, and southwards in the southern hemisphere from November to January. We then reverse these movements in the autumn.So you can find out on the Internet where and when we are abundant, available and hungry, and then book a local charter.
A boat is essential, as successful shore fishing for mahi mahi is limited to very few areas where there is deep water close inshore, and the fish there is few and little. It’s best to book through a service such as BaitYourHook.com, that filters out operations that aren’t dependable, efficient, and ethical, and where you can easily check reports from earlier clients. We are generally most abundant fairly close to shore and this abundance decreases towards the open ocean areas. This means that it is usually possible to book day charters from small harbours.
There are many ways to fish for us and by far the most common is to retrieve a fly, lure or bait rapidly across the surface of the ocean. Casting towards floating debris or weeds will greatly increase the chances of a strike and, in some areas, fishing around an ocean buoy can be very successful. Medium spinning tackle is the most effective and a wide variety of colours and shapes of lures can entice us to strike, while local knowledge can point the angler in the right direction.
Live or dead bait, such as squid, or jigs dropped along the mooring lines of ocean buoys also produces many fish. In recent years fly-fishing, using strong tackle, has proved increasingly popular, but the angler must be prepared for a spectacular and adrenaline-pumping fight. We really do not want to be landed and a fly rod, even a strong one, will be put to the ultimate test by a decent-sized mahi mahi. Our mouths are quite hard and bony making it extremely hard to set a fly well and our repeated leaps, while vigorously shaking our heads, will often dislodge even the sharpest hook.
Apart from our stunning beauty and fighting spirit, we – unfortunately for us – also appear to be very tasty for humans. This combination of rapid growth, spectacular appearance, and culinary appeal, along with the fact that when fishing for us you can usually land several large fish over a short period of time, make us among the most popular species for sport anglers.
Next in “Life History of a Fish”
Life History of a Fish: Largemouth Bass
by Scotty Kyle
Americans probably know more about me than any other fish, freshwater or marine. I am a prime “sport” angling species with perhaps more fanatical followers than any other American fish. There is a very large “industry” built around my species and a lot of money is being spent annually on trying to outwit my kind. There are TV series, massive prize tournaments, extremely specialised boats and motors, every kind of lure and bait you can imagine, plus some others beyond imagination, all aimed at helping humans to outwit me. Yet, despite all this effort and expense, I remain abundant and continue to spread through all the continents, except Antarctica, where it is far too cold for us. I am the largemouth bass. CONTINUE READING
