Comparing Invertebrates

Metazoans Also known as Kingdom Animalia –Multi-cellular –Develop from embryos –Divided into two groups based on the presence of a backbone

METAZOANS InvertebratesVertebrates Lack a backboneHave a backbone

Invertebrate Phylums Porifera Cnidaria Ctenophora Worms… Mollusca Arthropoda Echinodermata

PHYLUM PORIFERA Aka SPONGES

MICROCINA Sponge common in the Chesapeake Bay

LEUCOSOLENIA

BACKGROUND Porifera literally means animal with pores Sponges are simple and ancient DNA evidence points to these animals being ancestors of animals that are alive today

There are over 9,000 different species –Most live in salt water –Few live in fresh water Originally harvested in Greece 1000’s of years ago as a cleaning product

Body Plan / Structure Most primitive animal group Do not have organs, muscles, nerves, mouth, or digestive cavity Have specialized cells for different functions Bodies are asymmetrical (no symmetry)

Body Plan Porous body with two different types of openings ostia- pores on outside the water flows into oscula- large opening water flows out of

ostia

Skeleton- made of small hard spicules –spicules have different shapes and sizes –made of calcium carbonate or silica Spicules are “woven” together by a material called spongin

Feeding Filter feeders- eat plankton Use special cells to create a current of water collar cells- move their flagella to create current of water flowing through the sponge food and oxygen enter, waste exits

A 4 inch sponge ½ “ in diameter filters up to 30 gallons of water a day

SPONGE VIDEO

Reproduction Asexual Budding- new sponge grows on parent, falls off and creates a new animal Sponges can regenerate after being pulled apart

Sexual Eggs and sperm are released into the water Most species are hermaphroditic…Possess both egg and sperm Egg and sperm are released at different times to assure fertilization with a different sponge

Medicinal Uses Etc.. Many species contain toxic substances, probably to discourage predators. The chemicals also probably play a role in competition among sponges and other organisms

Some of these chemicals have been found to have beneficial pharmaceutical effects for humans

Ecology of Sponges (or how they are important to their environment) Marine animals take advantage of sponges chemicals by placing adult sponges on their bodies, where the sponges attach and grow Provide a home for a number of small marine organisms

Symbiotic relationships with bacteria and algae Some sponges (boring sponges) excavate the surface of corals and molluscs, –it is an important part of the process by which calcium is recycled.

Mobile Sponges Although they appear to be mostly sessile, some may move up to 4 mm a day