Invertebrate Animals Sponges

I -PHYLUM PORIFERA – SPONGES “Pore-bearing animals” Variety of sponges at coral reef

Glass Sponges They are deep water sponges that form large billowing growths up to ten feet in diameter and nearly seven feet high. They use silica and glass like spicules to form the support structure of the sponge.

Cloud sponges are found from Alaska to Mexico, typically in inlets and rock ledges at depths of 100 feet or deeper. They belong to a group that was present before the time of the dinosaurs.

Major Characteristics 1) Habitat – fresh (150 species), or salt water (10,000 species) 2) General Structure: No true tissues or organs (size – 1 cm – 2 meters) Tube Sponges

3) Movement – sessile in adult form, most adults remain firmly attached to a surface such as a rock

BODY PLAN: B) 1) Body wall with 2 layers of cells separated by a jelly-like substance 2) The sponge interior is lined with cells known as Choanocytes, or “collar cells”. Their beating flagella draw water into the sponge through pores.

3) Water enters the sponge through incurrent pores. 4) Water leaves the sponge through the osculum,(excurrent pore) a large pore in the top of the sponge

5) Support of the sponge is provided by a “skeleton” of protein fiber network called spongin, or in some sponges, a network of hard particles called spicules. Spicules are tiny, hard particles of calcium carbonate or silicon dioxide.

Spicules

Glass Sponge Spicules glass sponge

Glass Sponge Spicules

NUTRITION: C) 1) Sponges filter food from the water. They are “filter –feeders.” 2) They eat bacteria, protozoans, unicellular algae, and organic matter. In some cases they can filter several thousand liters a day.

Digestion: 1) Choanocytes(collar cells) digest food. 2) Archeocytes (amebocytes) distribute food thoughout the sponge. (complete digestion - intracellular)

Waste excretion- E) Diffusion of wastes directly into the water

Reproduction: F) 1) asexual – internal buds called gemmules = “food-filled” ball of archeocytes(amebocytes) surrounded by a protective coat made of organic material. The gemmules also survive harsh conditions that kill the sponge.

2) sexual: archeocytes (amebocytes) carry sperm to egg cells within the sponge, usually from another sponge, expelled into the water. 3) Sponges are hermaphroditic and can therefore produce both sperm and egg cells within the same animal. 4) Sponge larvae have flagella to leave the parent and find a new location.

Sponges are homes to other animals Red sponge with brittle star inside

Synthetic sponges

PURPLE SPONGE