Caulerpa brachypus is a green seaweed found in the Caulerpaceae family. This plant was first seen in 1860 by Irish botanist William Henry Harvey.
It comes from the Indo-Pacific region but has spread far and wide. Today, it’s known as an invasive species in the United States, Martinique, and New Zealand.
Description and Features
This seaweed has a creeping stolon that grows flat on the sea floor. From this stolon, it sends up blade-like fronds on short roots.
The fronds are tongue-like or strap-like in shape and can grow up to 5 cm (2 in) long.
They are mainly green, but sometimes they have yellowish edges. This plant often looks like other members of the Caulerpa genus.
There is also a lot of change between different groups of Caulerpa brachypus growing in different places.
Thriving in Dense Stands
When this seaweed finds a place it likes, it can grow very fast and form thick groups.
This makes it hard for other plants and animals to live in the same area.
Distribution of Caulerpa Brachypus
Caulerpa brachypus is from the warm Indo-Pacific region. It’s found in parts of East Africa, India, Southeast and East Asia, the Pacific Islands, and Western Australia.
In Western Australia, it’s spread along the coast in the Pilbara region.
This seaweed first showed up in the United States in Martin County, Florida, in 1999. By 2003, it had spread to the Indian River Lagoon.
In 2021, it was found on Great Barrier Island in New Zealand. It’s now seen as an invasive species in the United States, Martinique, and New Zealand.
Ecology and Invasiveness
Caulerpa brachypus might have a way of making babies like other members of its genus.
But a more common way for it to spread is by breaking apart. Pieces of the plant can break off and grow in new places.
In its native home, this seaweed is eaten by fish that keep it from growing too much.
But in Florida, few fish eat it, so it can grow a lot on off-shore reefs. This can make it hard for other plants and animals to live there.
This seaweed doesn’t like bright light, so it grows best in shady spots. It’s often found in deep water, where there is less light than at the surface.
Problems in Florida
In Florida, people call this seaweed the “killer algae.” It was first seen in the state in 1999.
By 2003, it had grown a lot and spread far. Nearshore reefs in Palm Beach County were so full of it that fish and lobsters could not live there.
In 2004, hurricanes wiped it out from the rocky reefs. But after a few years, it came back and grew thick again.
Causes of Invasiveness
Caulerpa brachypus might grow so well on Florida’s coast because of sewage in the water.
The extra waste can give the seaweed more food to grow. When the seaweed covers a large area, it can be fatal for the corals, sponges, and other animals that can’t move.
Animals that can move have to go find new homes.
You can check out what this plant looks like over here.
Caulerpa brachypus Characteristics
|Required Lighting:||Moderate High|
|Required Water Flow:||Moderate|
|Maximum Size:||1 in (2.5 cm)|