In this article we will discuss about:- 1. Origin of Cyclostomes 2. General Characters of Cyclostomes 3. Classification 4. Representative Types 5. Affinities. Origin of Cyclostomes: The Cyclostomata (Gr., cyklos = circular + stoma = mouth) are the living agnathans, they are primitive in many respects, but specialised in others. They are a modified and degenerate offshoot of the primitive [...]
In this article we will discuss about the external features of lamprey with the help of suitable diagrams. Also learn about its habit and habitat. Shape and Size: The body of adult Petromyzon is elongated, cylindrical and eel-like. Petromyzon marinus (sea-lamprey) attains a length of a metre, Lampetra fluviatilis (Lampern or common freshwater lamprey) reaches a length of about 90 [...]
In this article we will discuss about the anatomy of lamprey with the help of suitable diagrams. Body Wall: The skin is soft, slimy and consists of many layers of cells. The epidermis is composed mostly of unicellular gland cells that produce slimy secretion and its outermost cells border show cuticular striations. The dermis is composed of bundles of collagenous [...]