Sea Sheep

The sea sheep or sea sheep (Costasiella kuroshimae) is a species of invertebrate gastropod mollusk of the order of Opisthobranchs and the family Costasiellidae, being one of the 16 species belonging to the genus Costasiella, which includes sea slugs.

Its name comes from its cute appearance, resembling that of an animated sheep or cow. Its eyes are small and black.

These gastropods have colors ranging from yellowish brown to bright green, including other colors such as blue, yellow, green, red, purple, white and brown on their bodies.

The body length is 4-10.5 mm. Its cerata are flattened and this is the difference with respect to other species of the genus.

The most fascinating thing about them is that they are one of the few animals in the world that can photosynthesize. When they feed on algae, they absorb the chloroplasts and incorporate them into their own bodies in a process called kleptoplasty. This process can normally only be carried out by single-celled organisms, but for our slug it means that it can feed on the sun.

The algae that this mollusk feeds on are those of the Vaucheria genus, a genus within the plant kingdom that has a yellowish-green color.

It is a hermaphrodite organism, meaning it is both male and female. Mating occurs in water, where it then lays capsules measuring about 9-15 mm × 1.7 mm containing 2,000 to 4,000 eggs.

After 4 days, the eggs hatch, producing a veliger, which will later undergo a process of metamorphosis to become the well-known gastropod.

It is distributed in places where the algae it feeds on are found in Japan, Indonesia and the Philippines, in mangrove forests.

They live in intertidal zones, which are areas that are covered during high tide and visible at low tide. Because of this, it could be said that sea sheep can be found out of the water, on the coasts.

-It is one of the few non-plant organisms that can carry out photosynthesis, since its “leaves” can survive up to a couple of months due to the energy produced.

-For this reason, it could be said that Costasiella kuroshimae is a “solar-powered sheep.”