Development of Branchiostoma (Amphioxus) is indirect involving a larval stage. Early embryology of Branchiostoma is simple. Therefore, the transformation of egg, which having less yolk, into a complex and differentiated animal is far easier to follow than in any other vertebrate. The early development of Branchiostoma (Amphioxus) is of great phylogenetic significance because it resembles with those of invertebrates like [...]
In this article we will discuss about the external morphology of branchiostoma with the help of suitable diagrams. Shape, Size and Colour: Branchiostoma is about 3.5 to 6.0 cm in length. The body is slender, somewhat translucent, superficially fish-like, laterally compressed and pointed at both ends, hence, the name lancelet. The anterior two-thirds of the body is roughly triangular in [...]
The blood vascular system of Branchiostoma is of closed type. The blood is colourless and devoid of corpuscles and respiratory pigment. Blood is found not only in blood vessels but also in lymph spaces, around fin-rays, and in metapleural folds. Its main function is to transport the food and excretory wastes. Heart is not found in Branchiostoma. Most blood vessels [...]