The Fastest Growing Animal in the World
The salp, a marine animal from the family Salpidae, is remarkable for its incredibly rapid growth rate. In just 48 hours, salps can mature, making them the fastest-growing multicellular animals on the planet and playing a crucial role in ocean health.
Salps (Salpa fusiformis) are widely distributed across the Pacific and Atlantic Oceans, feeding primarily on plankton and any small organisms caught in their feeding nets. Often described as “jelly-like spheres” or “slimy buckets,” these transparent marine creatures have a gelatinous texture.
There are over 70 species of salps worldwide, with Salpa fusiformis being the most common. They can be found from the ocean’s surface to depths of around 800 meters, growing from 0.2 cm at birth to 10 cm when fully grown. Salps often form long chains that drift with ocean currents.
Salps move by using jet propulsion. They pump seawater through their bodies using muscular bands around their bodies. As the water is pushed out the back, salps collect food and propel themselves forward. This mode of movement places them among the group of jet-propelled animals.
Unlike jellyfish, salps do not have stinging cells. Their diet mainly consists of plankton, but they filter out any small particles caught in their mucous net. By filtering large volumes of water, salps play a significant role in combating climate change. A single salp swarm covering 100,000 km² can collect up to 4,000 tons of CO2 in one night.
Salps undergo two distinct life stages: the asexual oozoid stage and the sexual blastozooid stage. When an asexual oozoid is ready to reproduce, it produces long chains of salps, each a clone of itself. These salps then develop into sexual blastozooids. The eggs develop inside the salp, which then gives birth to juvenile salps. These juveniles swim away and grow into asexual oozoid individuals. Eventually, the entire chain transforms into male salps, releasing sperm to fertilize the eggs of neighboring female blastozooids.
With their ability to mature in just 48 hours and increase their body length by up to 10% per hour, salps are indeed the fastest-growing multicellular animals on Earth.
