Sailfish are a very well-known
species of fish (you've probably heard of them, and maybe even seen
one mounted) because of their popularity among sport fisherman.
They are world-renowned for the challenge they provide even the
most experienced anglers. In fact, there isn't much science knows
about this species of fish, except what observations fisherman have
gathered from encounters with it. Over-fishing of this magnificent
fish has led to a noticeable decline in their numbers, so that many
people who fish for them are putting them back after they've caught
them (called "catch and release"). Even as well known as they are,
sailfish are a difficult species to study because they are highly
migratory and are typically found many hundreds of miles from shore.
These two factors make it very difficult for scientists to locate,
tag, and collect data on specimens. Cooperation from sport fisherman
who prize this species is essential for scientists to learn more
about the sailfishes' range and behavior.
What little we do know about the
sailfish is limited to its range, habitat, growth, and diet.
Range and Habitat: Sailfish
are found in both the Atlantic and Pacific oceans with different
scientific names assigned to the fish in either ocean (Pacific -
Istiophorus albicans; Atlantic - Istiophorus platypterus).
However, scientists now believe that these fish are actually the
same species, the only difference being the ocean in which they
live and their size - the Pacific ocean sailfish tend to grow significantly
larger (up to 10 feet). Based on catch rates and water temperature,
it has been determined that sailfish prefer to live in warm waters
(approximately 79 degrees F), although they have been caught as
far north in the Atlantic as Cape Cod.
A sailfish leaping from the ocean with its
large sail like dorsal fin retracted against its body. Sailfish
usually raise their sails when they are excited or swimming
on the surface. |
Growth: Some studies have
been done to examine the growth rate of the fish with some pretty
amazing findings. After a female sailfish lays her eggs they hatch
36 hours later! They are also a fast growing species, where a hatchling
can grow up to six feet long in one year's time. How big do they
get? The average length is 6 to 8 feet, but the world's record holder
caught in 1994 weighed 141 pounds and was over ten feet long.
Diet: Flying fish and squid,
preferring tunas, mackerels, jacks and other fish that swim near
the ocean’s surface. Divers have reported seeing several sailfish
work together to corral their prey, using their high fins to create
a wall that keeps the smaller fish from escaping. They've also been
observed using their long, sharp bills to stun and skewer their
prey. Scientists have also photographed them hunting in groups,
flashing brilliant colors on their bodies when excited by their
predatory behavior during feeding.
Why Study this Fish?
When you first look at a picture
of this fish there are lots of questions that come to mind; "Why
the tall fin? Tell us all about that big fin!"; "Why the long beak?",
"How did it get to be so fast and why is it so fast?". If scientists
can study this fish more closely, many of these questions can be
answered. Most importantly, we study this fish, and all other fishes,
to learn more about their contribution to their ecosystem (the ocean
environment) and how they affect all other creatures, including
humans. Since we put significant pressure on this particular species
of fish by fishing for them for sport and for food, we need to learn
as much as we can about them to protect their numbers. Once we have
a better understanding of how sailfish live, how often they breed,
how quickly they grow, the best conditions for them in the ocean,
what they need to eat to stay healthy and robust, we can work to
ensure that the numbers of sailfish we take from the oceans isn't
more than the species can sustain without a decline in population.
