Annelids

I don't know why you would think blood appeared first with annelids...

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In animal kingdom annelids are the first animals to develop blood,Then in which animals first lymph is evolved?

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... structures glandular? 2. Any enzyme secretion? 3. Churning should take place in crop, gizzard or both? 4. What animal groups have these? (I think annelids, arthropods and aves. Any others?) 5. How are these structures specialized among various groups? (eg. the avian gizzard is specialized for ...

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... area of axon membrane over which exchange of ions can occur .. Giant axons are found in number of invertebrates including earthworms, marine annelids and crustaceans. They are thought to be associated with rapid escape responses, since rapid transmission of impulses is needed between receptors ...

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... skeleton is asimple , fluid-filled cell and is found in animals such as amebas . In higher invertebrates such as coelenterates , nematodes , annelids , and echinoderms , water held inside the body is shifted by muscles to bring about a change in shape or position of the animal . (........4.......) ...

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