The following points highlight the two main skeletal elements found in sponges. The types are: 1. Spongin 2. Spicules. Skeletal Element: Type # 1. Spongin: The spongin comprises of fibres of spongin and they resemble silk in appearance. These are proteinaceous secretion of the spongioblasts and form a network. In most cases, the spongin fibres are composed of protein, termed [...]
In this article we will discuss about the role and evolutionary significance of canal system in sponges. Role of Canal System: The canal system which draws water current inside the sponge's body and maintains a continuous uninterrupted flow of water, plays a vital role in the physiology of sponges, because it serves the various kinds of functions. (i) Nutrition: The [...]
The following points highlight the three main types of canal system encountered in sponges. The types are: 1. Ascon Type 2. Sycon Type 3. Leucon Type and 4. Rhagon Type. 1. Asconoid Type: The asconoid type of canal system is regarded to be the most simple and primitive grade of canal system. Asconoid type is present in these sponges whose [...]