Explain how using an open circulatory system constrains the size of animals.

An open circulatory system constrain animals size because there is no motor that pump the hemolymph (hemolymph is like the blood in invertebrate animals), in a closed circulatory system is the heart that works as a motor to move the blood throught all over the body.

So the hemolymph can not travel through long distances what constrain the size of the animals that have open circulatory system.

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

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