Sea sheep? Animals with wool and spiral-shaped horns not only exist in the grasslands, the sea has its own sheep, better known as
With a body of 4-10 mm, small black eyes, and a color ranging from yellowish brown to bright green, including other colors such as blue, yellow, green, red, purple, white and brown on its body, The sea sheep is one of the sea animals that feed on the sun.
Since it is one of the few non-plant organisms that can, since its “leaves” can survive up to a couple of months due to the energy produced, you could say that Costasiella kuroshimae is a “solar-powered sheep.”
Sea sheep, the unique sea slug
It was discovered in 1993 off the coast of the island of Kuroshima, in Japan, although it has also been located in the waters of the Philippines and Indonesia. But, beyond their appearance, the most curious thing about these marine creatures is their way of making the most of the algae they feed on on the seabed, with which they maintain a very particular symbiotic relationship, which also helps to maintain the balance of algae populations in their habitats. Although it is not the only reason that makes them special.
Some of its features are:
- The protuberances that these slugs have on their heads are not the horns of a sheep, but ‘rhinophores’, a sensory organ of prosobranch mollusks that serve as chemical sensors, which function as taste receptors.
- These slugs are hermaphrodites, that is, they are both female and male, and once reproduction has begun, they will lay between 2,000 and 4,000 eggs that hatch after about 4 days, giving rise to larvae that will soon acquire that characteristic shape. of sheep.
- The algae on his body allow him to carry out the kleptoplasty process.
- They prefer to live in areas with lush marine vegetation, as this provides them not only camouflage but also food.
- They feed on key marine plants, such as Avrainvillea and Halimeda, which are green algae.
- Leaf sheep sea slugs’ vibrant green color comes from ingested chloroplasts, making them resemble small underwater sheep grazing on aquatic vegetation.
Costasiella kuroshimae is capable of performing kleptoplasty
Within the sea slug, chloroplasts produce food from organic materials in the cell and sunlight.
It is a strategy, since the sea sheep, instead of always having to go looking for food, allows it to be stored inside itself, thus generating energy and matter when it needs it. And this theft of chloroplasts is known as a “kleptoplasty” process.
Some studies have found that chloroplasts can carry out photosynthesis within sea sheep up to between nine and 12 months, and throughout that period they continue to nourish the animal. What is still not understood is how the slug can maintain these chloroplasts for so long within its body.
Its population is in danger
Like all exotic animals, sea sheep face several threats, including habitat loss due to human activity and pollution.
Coastal development, trawling and climate change-induced ocean acidification are factors that can negatively impact the delicate habitats these sea slugs depend on to survive. Additionally, excessive collection for the aquarium trade can lead to further population decline.
This last point endangers the population, since they are usually hunted for a home aquarium, which is not recommended, because sea sheep require a specific environment that includes clean water and a constant temperature, to thrive, mainly because their Diet consists of specific algae, such as the green algae called Avrainvillea, which can be difficult to obtain and maintain in captivity.