The sailfish (Istiophorus platypterus) commonly known as the Atlantic sailfish or Pacific sailfish, is a highly recognizable billfish renowned for its extraordinary speed and majestic dorsal fin. As the fastest fish in the ocean, reaching speeds of up to 68 mph, it is a formidable predator. Its elongated bill, used to stun prey, and its streamlined body contribute to its exceptional agility.
The sailfish’s iridescent blue and silver coloration, highlighted by its expansive dorsal fin resembling a sail, makes it a captivating sight in tropical and subtropical waters worldwide.
Appearance
They have a unique appearance which makes them easily identifiable. Its sleek, hydrodynamic body is typically blue to gray dorsally, fading to silvery-white underbellies. Vertical bars adorn its flanks. Large, expressive eyes provide excellent vision for hunting.
The first dorsal fin stretches above them (almost the same length of their bodies) like a sail, hence where they got their name from. This “sail” can be raised or lowered, adding to the fish’s maneuverability and communication. Since they belong to the family of billfish, they have an upper jaw that juts out like a sword, similar to a swordfish. Both are short and concave.
The pectoral and pelvic fins are long with the pelvic fins almost twice as long and nearly reaching the origin of the first anal fin. The pelvic fins have one spine and multiple soft rays fused. The caudal peduncle has double keels and caudal notch on the upper and lower surfaces.
Their bodies are thick and long and can grow up to 10 feet.
Did you know…
The bill has sensitive receptors that detect vibrations and aid in prey detection. Additionally, specialized glands near the eyes secrete an oily substance, lubricating the body and further reducing water resistance.
Habitat
Sailfishes don’t live in coral reefs, coastal areas, or closed-off spaces. Instead, they live in the open ocean. They are found from the surface of the ocean as deep as light can reach, meaning they can be found on both surfaces and at the ocean’s depths.
They live in warm tropical water and therefore are migratory. They move away from the equator in the summer and back towards tropical regions in the winter.
The two main subspecies of sailfish, Atlantic and Indo-Pacific, range throughout the warm and temperate parts of the world’s oceans. It has been taken in the Mediterranean Sea, although few records exist for this region. In the western Atlantic Ocean, its highest abundance is in the Gulf of Mexico, the Atlantic coast of Florida, and the Caribbean Sea.
Spawning occurs in deep waters along the coast of North America and over the continental shelf off the West African coast. Spawning has been observed year-round in the eastern Atlantic, with a peak in the summer months.
Diet
Sailfishes are carnivores and prey on small fishes and crustaceans like octopus, and squid. Some of its prey include anchovies, tuna, sardines, herring, mackerel, and more. Its predatory hunting style is unlike a typical predator.
Reproduction
They reproduce through external fertilization. Female sailfishes use the dorsal fins to attract a male over the surface of the water. Once she releases the eggs, the males then fertilize them outside of the body. A single female can lay up to a million eggs that hatch after two to three days.
Females swim slowly through shallow water, with their dorsal fin above the water surface. One or more males accompany her and spawn near the surface. A large female may release 4,500,000 eggs while spawning
They have a life cycle as long as 10 years. Spawning occurs throughout much of the western Atlantic during the warmer months. A major spawning area is along the lower east coast of Florida.
Threats
Sailfish are not fished as food. Instead, they are caught for recreational fishing (a type of sport between sport fishermen) for their incredible speed. When hooked, these beasts will fight vigorously – jumping, leaping, and repeatedly diving against the fishing lines. It takes hours, and is often difficult, to catch a sailfish. They are also caught as bycatch by driftnets and harpoons.
Because of their speed and size, adult sailfish are only targeted by large ultra-predatory fish like sharks and orcas, which are also fast swimmers. Sailfish babies are preyed on by fish that usually eat plankton.
Although they are caught for game fishing, the population of sailfish is considered stable and is not under any protection or endangered status.
6 More Interesting Facts about Sailfish
- They only use their “sails” when hunting to help reduce the speed which in turn reduces the movement of their head, helping them to catch their prey with their bill.
- They have been in the ocean for 60 million years!
- They are considered to be very intelligent and incredible predators.
- They work as a team, cornering and driving schools of fish up against the surface of the ocean for easy feeding.
- They are one of the fishes that are at the top of the food chain.
- Some sources indicate that these fishes are capable of changing colors according to their mood or for confusing their prey.
FAQs
Are sailfish human-friendly?
No. Sailfish are extremely predatory and are not human-friendly. In fact, they fight violently when caught in fishing lines.
Is there a difference between a sailfish and a swordfish?
Yes, swordfishes are a lot bigger than sailfishes and can get bulkier too. Swordfishes are cylindrical, and sailfishes are laterally compressed. Swordfishes also have very small dorsal fins, unlike sailfish, which have a huge sail-like fin.
Are sailfish rare?
Sailfishes are fairly abundant and can be found in the open oceans in warm waters. They are also migratory and travel to tropical waters when the temperatures change according to the climate.
What is the behavior of sailfish?
They are generally not considered aggressive towards humans. While they are powerful predators in their natural environment, they typically pose no threat to divers or swimmers. Interactions with humans are rare, and sailfish tend to avoid encounters unless provoked or threatened. During hunting, sailfish can exhibit assertive behavior, using their bills to stun prey and actively pursuing their targets. However, this aggression is directed towards their natural prey and is essential for their survival.
What is the special role they play in the ecosystem?
As apex predators, they play a crucial role in maintaining the balance of marine ecosystems. By preying on smaller fish populations, they help regulate species abundance and prevent overpopulation. This control ensures that lower trophic levels have sufficient resources, promoting overall ecosystem health and biodiversity. Additionally, sailfish themselves serve as prey for larger predators like sharks and killer whales, contributing to the intricate food web.
