Phylum Porifera

General Characteristics SPONGES! Simplest of all animals _________________ No true tissues or organs _________________________ Marine and Freshwater Saltwater are colorful Freshwater are dull green color

General Characteristics Cont. Sponges are sessile as adults Free swimming larval stage called dipleurula Porifera means pore-bearing Water enters through pores bringing in food and oxygen ____________________________ Osculum- large opening at the top where excess water leaves

Water Flow Through the Sponge WATER OUT Water Flow Through the Sponge WATER IN Osculum

3 Basic Cell Types _______________ Mesenchyme Cells Choanocytes

3 Basic Cell Types 1. Pinacocytes- flat cells that line the outer surface of the sponge. May be slightly contractile ____________: a specialized type of pinacocyte; are tube-like in shape; contractile; and can regulate water circulation.

2. Mesenchyme Cells- move around in the mesohyl layer; are specialized for reproduction, secreting the skeleton, transporting/storing food. ____________: jelly-like layer just underneath the pinacocyte layer.

3. Choanocytes- flagellated cells that line the inner chamber of the sponge; called collar cells. Flagellum: flagella spins to create water currents to pull in water and food Collar: __________________________ (plankton) from the water

Choanocyte Choanocyte

__________________________ Consists of either one or all of the following: Spicule: microscopic needle-like spikes that are made of Calcium carbonate (CaCO3) or silica (glass). Spongin: a fibrous protein made of collagen

Sponge Skeletons Silica Spicules Limestone Spicules SPONGIN

Sponge Body Types 3 Kinds- Ascon __________ Leucon

Ascon ____________________ Are vase-like Least common type of sponge

________________ Sponge wall is folded into canals Choanocytes line the radial canals to move water

Leucon Have an extensively branched canal system. ___________________________ Multiple ostia for water to exit Increased surface area means more water can move through sponge

Body Forms Summary

Reproduction Sexual Reproduction- sponges are monoecious (male and female in the same body) Release sperm and eggs into the water from the Osculum Cross-Fertilization takes place in the ocean _____________________________

Sponge Releasing Eggs & Sperm Reproduction Sponge Releasing Eggs & Sperm

Reproduction Cont’ Sponges can regenerate (regrow) lost body parts through mitotic cell division (asexual) Sponges also reproduce asexually by ________________

Reproduction Cont’d gemmule Asexual Reproduction- involves the formation of gemmules ______________: resistant capsules that sponges release to survive unfavorable conditions. When conditions become favorable, the gemmules sprout into sponges.

_____________________ Phylum Porifera 3 Classes Class Calcarea Class Hexactinellida Class Demospongiae

Class Calcarea Spicules made of Calcium Carbonate Can have all three body forms __________________ Ex. Grantia

Class Hexactinellida ___________________________ Can have syncon or leucon body forms Often fused into an intricate lattice Glass sponges

Class Demospongiae Spicules made of silica, spongin, or both. ____________________ Ex: common bath sponge