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Water
A Rough Road for the Roughy
As many commercial fishers turn their efforts to the deep sea, some species are threatened by overfishing. This is very risky because populations may be wiped out before we know how many fish there are or whether they can bounce back. Another risk is that if the one species is depleted, then many other animals will be affected. Overfishing has already threatened some species. In 1978, fishers off the coast of New Zealand found they could haul up millions of meaty, red-orange fish from the deep sea. These fish, called "orange roughy," became very popular. Within 15 years, 80 percent were wiped out by overfishing. Researchers discovered that the orange roughy grows so slowly, it cannot breed until about the age of 20. This means that it will take an extremely long time for their population to recover. Strict limits on fishing were put in place just in time to prevent a total collapse.
Scientific name: Hoplostethus atlanticus
Size: one foot long
Weight: two pounds
Habitat: deep seas around the world, with the largest population near New Zealand
Diet: fish, squid, and crustaceans
Characteristics: reddish body, large head
Major threat: overfishing
It will take a long time for orange roughy populations to recover. The main reason for this is that:
they grow slowly and mature late
the fish they eat are endangered
they live at such great depths
Correct!
The main reason it will take so long for orange roughy populations to recover is that they grow slowly and mature late. They don't breed (reproduce) until they're 20 to 30 years old.
Orange roughy are "synchronous spawners." "Synchronous" means "happening at the same time," so synchronous spawners are fish that:
swim in unison
release eggs and sperm into the water at the same time
spawn at the same time everywhere in the world
Correct!
Orange roughy release eggs and sperm into the water at the same time. After orange roughy spawn, their fertilized eggs float toward the surface, where they hatch into larvae (tiny babies).
Orange roughy live more than 100 years.
Fact
In fact, experts believe orange roughy may live up to 150 years. They are one of the longest-lived fish in the ocean.
Orange roughy are sometimes known as "slimeheads."
Fact
The name "orange roughy" was adopted in the 1970s because the nickname "slimehead" didn't sound very appetizing on a menu!