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, [...]
In this article we will discuss about Sycon:- 1. Habit and Habitat of Sycon 2. Structure of Sycon 3. Canal System 4. Physiology of Water Current Production 5. Microscopic Organisation 6. Nutrition, Respiration and Excretion 7. Reproduction 8. Development. Contents: Habit and Habitat of Sycon Structure of Sycon Canal System of Sycon Physiology of Water Current Production in Sycon Microscopic [...]
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 [...]