Phylum – Porifera The Sponges Read 130-133

The Sponges – Phylum Porifera

Taxonomy Kingdom – Animalia Subkingdom – Parazoa (lacks tissues) Phylum – Porifera (pores)

Characteristics Porifera Porus (pore) + Fera (bearing) Simplest of all animals Contain specialized cells but no other organization level Most are marine Saltwater sponges are brightly colored

Characteristics Freshwater sponges are small and dull green color Size – 2 meters to 2 cm No nerves - therefore - No coordinated movement Single or colonial

Characteristics Water enters through pores bringing in food and oxygen Filter feeders on plankton Osculum – large opening at the top where excess water leaves

Draw or trace diagram of a sponge from page 131 in your text book

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

Characteristics Asymmetrical Sessile as adults (attach to rocks) Free-swimming larval stage called Dipleurula Also reproduce by fragmentation (pieces break off & form a new sponge)

Sponge Body Structure Inside body cavity of sponge is hollow Called the Spongocoel Have 2 cell layers: Outer epidermis Inner endoderm Jelly-like material between cell layers called mesenchyme

Collar Cells line the gastrovascular cavity & capture food Amebocytes digest & distribute food

Specialized Cells Collar cells line inside of body cavity (spongocoel) Have flagella that spins to pull in water & food Collar traps plankton (food) from water Collar Collar cells

Other Specialized Cells Amebocytes: Pick up food from collar cells Finish digestion Move through the mesenchyme & take food to other cells

Skeletal Structure of the Sponge Skeleton made of network of protein fibers called Spongin Spicules are hard spear or star-shaped structures Spicules made of CaCO3 (limestone) or silica SiO2(glass)

Sponge Skeletons Silica Spicules Limestone Spicules SPONGIN

Sponge Skeletons VENUS FLOWER BASKET SPICULES

Spicule type determines classification Phylum Porifera Class: Calcarea (calcerous sponges having spicules)

(horn sponges, like the bath sponge) Phylum Porifera Class: Demosponginae (horn sponges, like the bath sponge)

(coralline or tropical reef sponges) Phylum Porifera Class: Scleropongiae (coralline or tropical reef sponges)

Phylum Porifera Class: Hexactinellida (glass sponges).

Sponge Reproduction Sponges can regenerate (regrow) lost body parts through mitotic cell division (asexual) Sponges also reproduce asexually by budding

Sponge releasing eggs & sperm Sponge Reproduction Sponges are hermaphrodites (produce both eggs & sperm) Sponges reproduce Sexually by releasing eggs & sperm into the water from the Osculum Cross-fertilize each other’s eggs Sponge releasing eggs & sperm

Surviving Harsh Conditions Gemmules are specialized buds made to survive harsh weather (hot or cold) Contain food, amebocytes, and a protective covering of spicules Released when a sponge dies Resist dessication (drying out) Become adult sponge conditions become favorable

Feeding Filter Feeders Collar cells collect particles as they pass through the Pore Cells Items consumed are Resist d diatoms, protozoans, bacteria nad organic matter

Branching Tube Sponge

Stove Pipe Sponge

Vase Sponges

Barrel Sponges

Ball Sponges

Rope Sponges

Importance of Sponges Reefs provide habitat for many animals Vacuums of the sea -- clean up the sea floor/oceans Sponges are a commercial venture Several medicinal compounds, including antibiotics, antivirual drugs, and drugs for leukemia come from sponges.

Cool Stuff – Regeneration! Tremendous ability to repair and restore lost parts. Can also reconstitute selves if totally disintegrated. Sponge tissue has some similarity to human connective tissue. Could lead to aid in tissue transplantation.

Embryology Development Weird and different from any other animal. Larval stage is usually a flagellated and free swimming. Interior has all cells of sponges but no choanocytes. Settles. Creeps around on flagella and eats extracellularly.