Photo by Mika d’Eau
With more than 4500 species, flatworms are found at very various depth, from very shallow to very deep reefs. Maldives are host to various astonishing species.
They mainly crawl on the reefs, looking for food or a partner to mate with. Sometimes you can see them swimming graciously from one place to another, either looking for a new place where to eat or escaping a disturbance.
Flatworms are especially beautiful and come in very various colours, from plain to extremely colourful. They lack circulatory and respiratory organs, oxygen reach and carbon dioxide leave all parts of their bodies by simple diffusion. Most flatworms have no anus and regurgitate undigested material through the mouth.
The flatworms “fence” using extendable two-headed dagger-like stylets. These stylets are pointed (and in some species hooked) in order to pierce their mate’s epidermis and inject sperm into the haemocoel in an act known as intradermal hypodermic insemination, or traumatic insemination. They are hermaphroditic (having both male and female sex organs) and they typically reproduce both sexually and asexually. The majority of sexual reproduction is through cross-fertilization (where both individuals fertilize each other).
Marine flatworms are primarily carnivorous, feeding on small animals like tiny worms, crustaceans, mollusks, tunicates, and sometimes even small fish, depending on the species; they can also eat algae or scavenge dead matter depending on availability, with most species having a specialized diet within their niche.
Photo by Mika d’Eau
