The dolphinfish (also known as the Mahi-mahi) is a large fish that can be found in warm tropical climates.
Despite the name “dolphinfish” this fish is not related to the dolphin family at all and are not marine mammals, they are fish and like most fish they are cold-blooded, produce eggs and breathe using gills.
One common theory as to why these fish are referred to as “dolphinfish” has to do with the fact that these fish are quite large in size (about the size of a small dolphin), however it has been quite difficult to pin-point the origin of this name.
Recently these fish have taken on their respective names “Mahi-mahi” and “pompano” to avoid confusion with the cetacean species, which the marine mammal dolphins are a part of.
Physical Characteristics
In terms of size the dolphinfish can reach lengths of up to 4 ½ ft and weigh up to 40 lbs (15 – 30 lbs on average).
These ray-finned fish vary in color from blue and green to yellow and brown with multiple shades running from the top of their body to the bottom.
They have a long dorsal fin which runs from the head to the lower back and a tall but narrow shaped body.
Male and female dolphinfish can be easily distinguished by the shape of their head.
Male dolphinfish have pronounced heads with an obtrusive forehead, while female dolphin fish have rounded heads.
Like other vertebrae fish these fish swim in a horizontal snake-like fashion as compared to cetaceans that swim with a vertical movement by arching their backs and tails.
The Mahi-mahi dolphinfish makes up one of two fish within the Coryphaenidae family; the other fish is the pompano dolphinfish.
Diet
Dolphinfish are known to eat a variety of prey such as crabs, crustaceans, small fish, squid and sargassum weed among other sea dwelling creatures and plant life.
Habitat
The dolphinfish can be found living near the coastline or in offshore warm tropical – sub tropical waters above 90 °F (32 °C) both in and around the equator throughout the world.
These surface dwelling fish can be found primarily in the Atlantic, Indian and Pacific oceans.
Some of the most popular areas known for hunting these fish include Costa Rica, the Gulf of Mexico, Florida & Hawaii among other ocean rich locations.
Social Structure
Young dolphinfish can often be seen traveling in groups of up to 50 or more fish in order to minimize their risk of being attacked.
As these fish age they tend to travel in smaller pods and in some cases may only travel in pairs.
Unlike marine mammals that give birth dolphinfish are born from eggs and are not given support or nurture from their mother or father.
Survival often depends on their ability to adjust to their surroundings quickly and find shelter in large groups of young dolphinfish.
Reproduction
The dolphin fish is one of the fastest known growing fish reaching sexual maturity within the first 6 – 12 months of life.
Female dolphin fish can lay anywhere from 100,000 – 1,000,000 eggs at a time and can lay eggs 2 – 3 times per year!
Fertility and laying eggs can occur at any time during the year as these fish do not have a primary mating season.
The average lifespan of these fish is 3 – 4 years with a few fish living to the age of 5.
Threats and predators
Other than facing threats from humans that hunt these fish for sport and/or food dolphinfish face threats from a number of different predators such as yellow-fin tuna, a variety of marlin fish species, swordfish, sharks, seabirds and a number of marine mammals.
Unlike “real dolphins” cetaceans these dolphinfish are not illegal to hunt.
In fact the species is quite plentiful and a source of food for some countries, however some scientists and researches believe there may be some toxins that could be passed on to humans through the consumption of these fish.