Panulirus ornatus facts for kids
The ornate rock lobster (Panulirus ornatus) is a large type of spiny lobster. It's also known as the tropical rock lobster. These lobsters go through 11 different larval stages as they grow.
Quick facts for kids Panulirus ornatus |
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Panulirus
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ornatus
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You can find Panulirus ornatus across a huge area called the Indo-Pacific. This stretches from the Red Sea in the west to Japan and Fiji in the east. They live in shallow waters, usually less than 50 meters deep.
People catch these lobsters using nets or spears in many places. In Northeast Australia, there's been a special fishing industry for them since 1966. The Great Barrier Reef Marine Park Authority helps manage this fishing. These lobsters have also moved into the Mediterranean Sea through the Suez Canal. This is called a Lessepsian migration.
This lobster species is very important for fishing in countries like Vietnam, Papua New Guinea, and Australia. Because so many are caught, countries like Australia and Indonesia have started successful aquaculture (farming) programs.
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What They Look Like
The ornate rock lobster is a big lobster with a blue-green shell, called a carapace. It has large horns on its head. Its body has clear patterns of stripes and spots in different colors. Its walking legs also have cool stripe patterns, making it look a bit like a spider.
What They Eat
Panulirus ornatus eats many different small sea creatures. Their diet includes clams, snails, and even other small crustaceans. These lobsters need special nutrients called carotenoids. Carotenoids give them energy and help them grow. They are also important for reproduction and staying healthy.
In lobster farms, lobsters are often fed special food. This food contains carotenoids, especially a type called astaxanthin. Some feeds use nutrients from blue and green-lipped mussels. However, studies show that these mussels alone don't provide enough carotenoids for the lobsters to grow well.
Breeding and Life Cycle
Every year, Panulirus ornatus lobsters travel a long way to breed. They migrate from the Torres Strait to Yule Island in the Gulf of Papua. This journey starts in late August. During this time, the females develop eggs, mate, and lay their first batch of eggs. The larvae are released when the lobsters arrive at the reefs in the Gulf of Papua.
The breeding season lasts from November to March or April. After their migration, male and female lobsters separate. Males go to shallower water, and females go to deeper water until their eggs hatch. Female lobsters can produce up to three groups of eggs each season. Each new group of eggs is usually smaller than the last.
Most breeding lobsters are about three years old. Males that breed are usually bigger than females. Their shells can be 100–150 mm long, while females' shells are 90–120 mm long. After breeding, many adult lobsters do not survive.
The adult lobsters do not travel back after breeding. They migrate to the Gulf of Papua so their larvae can spread out. Ocean currents help carry the larvae towards the Torres Strait. Young lobsters then travel back to the adult habitats in the northern Torres Strait. They stay there for 1-2 years until they are old enough to breed. Then, they join the annual migration themselves.
Lobster Farming
These lobsters are great for aquafarming because they grow very fast. In the wild, it only takes about 18 months for P. ornatus to reach 1 kg. Lobsters that grow bigger than 1 kg are worth more money. Because of this, countries like Vietnam and the Philippines use special feeding pellets to help them grow large.
Baby Lobsters (Pueruli)
Selling wild-caught, grown lobsters first became popular in countries like Vietnam and China. In the early 2000s, people found huge numbers of P. ornatus in Indonesia's waters. This meant Indonesia could become a leader in lobster farming. Now, P. ornatus is a very valuable resource for Indonesian fisheries.
These lobsters are especially common in their puerulus stage. This is a special stage between a tiny larva and a young lobster. At this point, they are called 'seed lobsters'. There are many more pueruli than young lobsters, so they are easy to collect. Fishers dive down to special places where pueruli like to settle. They carefully collect them. These baby lobsters are then moved to farms to grow bigger for sale.
This practice helps both humans and lobsters. People can export and eat many lobsters. Also, the lobsters have a much lower chance of dying. In nature, about 99% of pueruli die. But when they are caught and raised in farms, less than 25% die. So, farming helps produce more lobsters and can even help natural populations grow.
Some government officials have tried to make rules about catching seed lobsters. In 2015, a law said lobsters had to weigh at least 200g to be caught. Later, in 2016, a new rule stopped growing out lobsters in farms. But catching and farming seed lobsters had been a way of life for thousands of families in Indonesia for years. So, these practices continued secretly. By 2019, it was thought that even more people were fishing for pueruli than before the new laws.
See also
- Panulirus cygnus, the "western rock lobster"
- Jasus edwardsii, the "southern rock lobster"
- Spiny lobster culture in Vietnam
