card
200

orange roughy

OLogy Series
animal
card
200

orange roughy

OLogy Series
animal

For centuries, orange roughy went mostly unnoticed by humans. These fish thrived in the dark, the cold, and the intense pressure of the deep sea. When fishing boats started reaching new depths in the 1970s, orange roughy were fished almost to extinction. Today, orange roughy are protected by fishing limits. But it will take decades for their populations to recover.

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.

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

Are you right?

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

Are you right?

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
or
Fiction
?

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
or
Fiction
?

Fact

The name "orange roughy" was adopted in the 1970s because the nickname "slimehead" didn't sound very appetizing on a menu!

orange roughy
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

Image credits: courtesy of USDA, Office of Seafood and Office of Regulatory Affairs, Regulatory Fish Encyclopedia.