Phylum Porifera

Kingdom: Animalia Subkingdom: Parazoa Phylum: Porifera Cellular level of organization. Phylum: Porifera a. Body is perforated with 2 types of pores: 1.Ostia(inhalant or incurrent siphon):numerous ,small for entering water 11.Osculum(exhalant or excurrent siphon):less in number,large in size for getting water out of body

b.Body with single cavity(Spongocoel) or (Paragastric cavity)lined with (Choanocytes)or(collar cells).

c. With 3 types of sponge structure or canal system: Ascon Sycon Leucon

d. With internal skeleton of: 1. Spicules Calcareous Siliceous 2 d. With internal skeleton of: 1.Spicules Calcareous Siliceous 2.Spongin fibers 3.both

Body wall

Body wall

This phylum is divided into 4 classes according to: The skeleton of sponge The sponge structure

Class1:Calcarea (calcareous sponge) With calcareous spicules Ascon or sycon or leucon sponge structure Ex.1 :Lecosolenia sp. (Ascon type) Ex. 2 :Grantia sp. (Sycon type)

Class2 : Hexactinellida (glass sponge) With siliceous spicules. Sycon sponge structure. Ex.: Euplactella sp. (Venus flower basket) Class3 :Sclerospongia (coralline sponge) With siliceous spicules+spongin fibers covered with calcareous coat. Leucon sponge structure. Ex.: Ceratoporella sp.

Class4 : Demospongia (normal sponges) With siliceous spicules or spongin fibers or both Ex.1: Chalina sp. (finger sponges) Siliceous spicules+spongin fibers Ex.2 : Euspongia sp.(bath sponge) Spongin fibers only.

Reproduction in Porifera Asexual Sexual

Sexual Amphiblastula larva Parenchymula larva Calcerea Demospongia The flagellate larva in which there is a cavity filled with gelatinous connective tissue. a free swimming larva that is a blastula with small flagellated cells in one hemisphere and large nonflagellated cells in the other

Asexual Gemmule Gemmules are internal buds found in sponges that are the result of asexual reproduction, and are a response to a hostile environment.They are resistant to desiccation (drying out), freezing, and anoxia (lack of oxygen) and can lie around for long periods of time.. Gemmules are made up of amoebocytes surrounded by a layer of spicules and can survive conditions that would kill adult sponges. When the environment becomes less hostile, the gemmule resumes growing

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