THE NONCOELOMATE ANIMALS

Subkingdoms of Kingdom Animalia Name, characterize and identify the phyla belonging to the two sub kingdoms.

The four most successful of the 14 phylum of the primitive invertebrates Porifera - sponges Cnidaria – jelly fish, hydroids, sea anemones, corals Platyhelminthes - flatworms Nematoda – roundworms

PHYLUM PORIFERA

List 10 general characteristics of sponges The simplest multicellular animals. Think porous, aquatic animals that are sessile as adults. Built like rigid, porous bags (> 5,000 species) All are aquatic; 98% are marine No symmetry Multicellular, but the various types of cells work independently

They have no nervous system, no muscles, nor any organs Sessile as adults, attached to a substrate Have a ciliated, free-swimming larva Digestion is intracellular (no gut) Excretion and respiration by diffusion Asexual and sexual reproduction seen

Sponges have many types of specialized cells living in the gelatinous matrix which is supported by spicules and/or spongin

Cell organization No tissues but has different types of cells Cells are organized and recognize each other Cells are specialized for different functions

Basic structure of a sponge Coloring worksheet Define the following: –Osculum –Pore cell –Epithelial cell – choanocyte ( collar) cell –Amoebocytes –mesenchyme –spicules –Spongin –Central cavity

Body structures The inner cavity is called the spongocoel The middle layer is a non-living gelatinous layer, the mesohyl. For support it contains the protein collagen, as well as spicules and/or spongin The outer covering is the epidermis

Collar Cells Choanocytes (collar cells): Round cells with a single flagellum encircled by a collar of microvilli that act as a sieve, capturing nutrientsChoanocytes (collar cells):

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SPICULES Spicules are the non-cellular structures that support the sponge body Spicules are made of calcium carbonate (calcareous spicules) or silica (siliceous spicules) Sponges are classified on the shape and the chemical structure of their spicules, if any

SPONGIN All sponges have the protein collagen in their extracellular matrix, making up the fibrous part of their skeleton

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WATER FLOW Water flows through ostia (pores) in the epidermis then through canals and chambers. The passageways are lined with the choanocytes that create currents The canals can be simple or very complex The main body cavity is the spongocoel; the exit openings are called oscula (osculum, sing.)

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Explain how sponges feed

Orange Barrel Sponge at Tunnels, Grand Turk 4 feet tall, 2 feet across Dept: 50 feet Sponges eat by pumping water. Often homes for starfish.

Pictures of sponges mhttp:// m

How do sponges reproduce asexually? Asexual - fragmentation – when fragments break off form the parent and form new sponges external buds. Buds may break off, float away and eventually settle and become separate animals

How do sponges reproduce sexually Most sponges are hermaphrodites. What does this mean? –All sponges can reproduce both asexually and sexually (they are hermaphrodites) In sexual reproduction the zygote develops into a ciliated larva that swims away from the parent and settles onto a substrate to develop into an adult sponge

THE PORIFERA 25 SPONGE LARVA

CLASSIFICATION The are three classes of sponges, based mainly on the chemical composition and the shape of their spicules –Class Calcarea: Spicules of calcium carbonate that are straight, or have three or four rays –Class Hexactinellida: Glass sponges. Mostly deep- sea sponges with a vase or funnel-shaped body. Six- rayed siliceous spicules –Class Demospongiae: 95% of sponges. Siliceous spicules, if any, not 6-rayed. May also have spongin. Includes bath sponges

THE PORIFERA 27 CLASS DEMOSPONGIAE

THE PORIFERA 28 VENUS’ FLOWER BASKET (A Glass Sponge)