Spectacled porpoise facts for kids
Quick facts for kids Spectacled porpoise |
|
|---|---|
 |
|
| Subadult female spectacled porpoise | |
 |
|
| Size compared to an average human | |
| Conservation status | |
| Scientific classification | |
| Genus: |
Phocoena
|
| Species: |
dioptrica
|
 |
|
| Spectacled porpoise range | |
The spectacled porpoise (Phocoena dioptrica) is a small porpoise that lives in the Southern Ocean. It's one of the least studied ocean animals. This is because it lives in faraway places. Most of what we know comes from porpoises that washed ashore. We also learn from a few times people have seen them in the ocean.
Contents
What Does a Spectacled Porpoise Look Like?
Like other porpoises, the spectacled porpoise does not have a beak. It has small fins on its sides that are rounded. Its top fin, called a dorsal fin, is shaped like a triangle.
Interestingly, male and female porpoises look a bit different. Adult males have much bigger and rounder dorsal fins than females.
Female porpoises can grow up to 204 centimeters (about 6.7 feet) long. Males can be even bigger, reaching up to 224 centimeters (about 7.3 feet). The heaviest female found weighed 85 kilograms (about 187 pounds). A male was recorded at 110 kilograms (about 242 pounds).
Spectacled porpoises have special colors. Their back is black, and their belly is white. This helps them blend in with the ocean. Sometimes, the line between black and white looks a bit blurry. They also have a dark patch around their eyes. This patch is clear on both young and adult porpoises.
Some porpoises have a light patch near their dorsal fin. They might also have a dark line around their blowhole. Females are usually lighter in color. Young porpoises might have a grey back instead of black. Their belly is a lighter grey. They also have a clear line connecting their mouth to their side fin.
Where Do Spectacled Porpoises Live?
Spectacled porpoises are thought to live all around the Southern Ocean. They mostly live in the open ocean. But sometimes, people see them near the coast.
They have been found in cool, cold, and even Antarctic waters. The water temperature where they live is usually between 0.9°C and 10.3°C (about 34°F to 50°F).
Porpoises that have washed ashore have been found across the southern part of the world. This includes places like Brazil, Uruguay, Argentina, and the Falkland Islands. They have also been found near New Zealand, Tasmania, and South Australia. This wide spread shows they live all around the bottom of the world. They might travel with cold ocean currents like the Falkland Current.
People have also seen spectacled porpoises in the ocean in many places. These include waters near Patagonia, South Georgia, and Kerguelen. Some have even been seen south of 64°, in Antarctic waters.
What Do Spectacled Porpoises Eat?
We don't know much about what spectacled porpoises eat. But scientists think they hunt for fish and squid. No one has ever seen them hunting in the wild.
However, scientists have looked at the stomachs of porpoises that washed ashore. They found things like anchovies, small shrimp-like creatures, and squid beaks. They also found parts of a fish called an ornate cowfish.
Reproduction and Life Cycle
Not much is known about how spectacled porpoises have babies. In one area, studies suggest that young porpoises are born around 100 centimeters (about 3.3 feet) long. This usually happens in late spring or summer, from November to February.
We don't have information on how long they are pregnant. We also don't know how long mothers feed their babies milk. And we don't know how often they have babies.
Naming the Spectacled Porpoise
The spectacled porpoise got its name from a French scientist named Fernando Lahille in 1912. He named it for the two dark patches around its eyes. The Latin word dioptrica means 'spectacled'. In Spanish, it's called 'marsopa de anteojos', which means 'spectacled porpoise'.
Scientists have studied the DNA of these porpoises. They found that spectacled porpoises are closely related to Burmeister's porpoise. They are less closely related to the vaquita. All these porpoises are part of the Phocoena family.
How Many Spectacled Porpoises Are There?
We don't know how many spectacled porpoises there are. We also don't know how connected their groups are across the Southern Ocean.
Scientists have gone on research trips to the Antarctic. Between 1978 and 2004, they saw spectacled porpoises 28 times. But these sightings were only in good weather. It's possible they missed porpoises when the weather was bad.
Scientists hope to use special listening devices to find more porpoises. This could help them learn more about where these animals live. But no such studies have been done yet.
Dangers and Threats
Spectacled porpoises can be hunted by other large ocean animals. These include sharks, leopard seals, and killer whales.
Sometimes, birds like kelp gulls will eat porpoises that wash ashore. They can eat a porpoise carcass very quickly, sometimes in just an hour or two.
In the past, people living in Tierra del Fuego used to eat spectacled porpoises. This was between 6,000 and 1,400 years ago. It's possible the porpoise was a common food source for them.
More recently, porpoises might get caught by accident in fishing nets. Fishermen sometimes use porpoises as bait for crabs. We don't know how often this happens. We also don't know how much it affects the porpoise population.
Getting caught in fishing nets is probably the biggest danger from humans. Porpoises and other small ocean mammals can get tangled in nets and drown. This is because their echolocation (like sonar) might not detect the thin net lines. We don't know how many porpoises are caught by accident. But porpoises often wash ashore in areas where a lot of fishing happens.
Conservation Status
The IUCN helps decide how endangered animals are. In 2008, they said there wasn't enough information about spectacled porpoises. But in 2018, they changed its status to 'Least Concern'. This means they are not currently in danger of disappearing.
However, scientists agree that fishing nets are a threat. Also, the number of porpoises washing ashore in Tierra del Fuego might be too high. The 'Least Concern' status is temporary until more information is gathered.
Spectacled Porpoises in Human Care
There have been at least two times when a living spectacled porpoise was taken into human care. Both times, it was for medical help after they washed ashore.
One young female porpoise washed ashore in Australia in 1997. She was very tired and confused. Rescuers tried to help her back into the water, but it didn't work. So, they took her to a rescue center. She died five days later. Doctors found some damage inside her, but they couldn't find a clear reason for her death.
Another adult male porpoise washed ashore in Argentina in 2019. He was very thin and dehydrated. He was also taken to a rescue center. He died four days later.
See also
In Spanish: Marsopa de anteojos para niños
