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 classes of Phylum Porifera. The three classes are: 1. Calcarea or Calcispongiae— (Calcareous Sponges) 2. Hexactinellida or Triaxonida or Hyalospongiae—(Glass Sponge) 3. Demospongiae. Phylum Porifera: Class # 1. Calcarea or Calcispongiae— (Calcareous Sponges): [Calcarea, L. Calcarious = limy, Calcispongiae, L. Calcis = genitive of calx = lime or chalk] Features: (i) Exclusively marine, [...]
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 [...]