Acanthobdellida

leech order

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July 23, 2026

Quick Summary

The Acanthobdellida are a primitive order of leeches, characterized by the presence of setae on their five anterior segments and the absence of an anterior sucker. These leeches are parasitic on fish and are found in Lake Baikal. Leeches, in general, are segmented worms belonging to the phylum Annelida. They typically have a small sucker at the anterior end and a larger one at the posterior end, with a fixed number of 34 body segments. While some leeches are predators or scavengers, many are parasitic, feeding on blood or other bodily fluids.1234

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Annotated classification
Order Acanthobdellida Primitive group; setae present on 5 anterior segments; no anterior sucker; parasitic on fish in Lake Baikal (U.S.S.R.); size, small; genera include Acanthobdella. Order Rhynchobdellida An eversible pharynx used to penetrate host tissue; jawless; distinct blood vessels contain colourless blood;
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Order Acanthobdellida Primitive group; setae present on 5 anterior segments; no anterior sucker; parasitic on fish in Lake Baikal (U.S.S.R.); size, small; genera include Acanthobdella. Order Rhynchobdellida An eversible pharynx used to penetrate host tissue; jawless; distinct blood vessels contain colourless blood;
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