Marine Flatworms

Flatworms can have stunning colours. This is to advertise that they are highly poisonous!They are one of the simplest of all the animals with three body layers. Why is this important? Corals and anemones are one phylum that has only two body layers; an external skin layer and an internal digestive layer. The middle section is made of jelly. All other animals on the planet have a middle layer filled with organ systems, muscles and skeletons. They are far more advanced than the Jellies and corals. This is a huge step forward in the evolution of life. Flatworms were one of the first to go with this advanced life form. However, they made a lot of very significant advances in that they were trailblazers in many of the really important developments in life processes. They were the first to use a 'head' with concentrated senses such as a brain, sight ; they developed the idea of penises and vaginas, and internal reproduction, they developed the idea of left and right side' This enabled a stereo view of the universe including forward movement and coordination, symmetry allowed locomotion. They are a really important little animal because of the incredible number of innovations that they came up with. Kidneys, heart, digestive canal, sex organs, a brain and more. They even developed the first 'Antennae" and then used their concentrated senses to become the first predatory hunter. In my marine biology course, we explore the many reasons why this little insignificant animal is so important in the scheme of evolution of life. They certainly made many enormous leaps forward, these early two sided Bi-laterans.

The three main groups of Flatworms are Marine Flatworms , Tapeworms and Flukes. (Fish parasites.).


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Flatworms are conspicuous to advertise that they are toxic.

Many can swim quite well using an undulating waving movement of the lateral folds.

The Persian Carpet Flatworm is known to have symbiotic Zooxanthellae or algae living within its body. This supplements its diet with glucose as well as making additional oxygen..
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Many other animals imitate flatworms. Fish know how toxic that they are so plenty of mimic flatworms can be found. (Fish, Sea slugs) You can see their antennae on the right end. Hancock's Flatworm.The scientific name Pseudobiceros sp refers to the two false horns which are the rudimentary antennae. Pseudo = false; Bi = two and ceros = horns.