Marine Invertebra

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Sponges- PoriferaJellyfish, Hydroids, Corals, Sea Anemones – Cnidaria

Comb Jellies- Ctenophora Chitons, Snails, Bivalves, Octopi, Squid,

Nautilus, Nudibranchs, Cuttlefish- Mollusca- Sea Spider, Crabs, Shrimp, Krill, Amphipods,

Copepods, Barnacles- Arthropods- Sea Stars, Ophiuroids, Sea Urchins, Sea

Cucumbers, Crinoids- Echinodermata- Tunicates and Lancelets- Hemichordates- Marine Worms

Phylum's of Marine Invertebrates

Sponges

Considered an animalSimplest of all animals with many specialized

cellsAsymmetrical – no symmetryVariety of shapes and colorsEvolved from a single celled Eukaryotic

(Protistans)Loose aggregation of cells. Shapes may be determined by the shape of the

sediment and water currents flowing by them.

Characteristics

Calcarea are chalky sponges with calcium carbonate spicules

Hexactinella includes glass sponges & the Venus flower basket with silica spicules

Demospongiae include horny & bath sponges with only spongin or spongin & silica spicules

Sclerospongiae are coral sponges & have spongin & silica and calcium carbonate spicule

Classes of Sponges

Built around a system of water canals.Body is full of tiny holes called pores or

ostia, where large amounts of water circulate nutrients, oxygen, and remove waste.

Water enters through the ostia -> carried to the spacious cavity called the spongocoel -> water then exits the spongocoel through a large opening called the osculum.

Structure and Function

Collar cells or choanocytes have a flagellum and when they all move it creates a great force which then moves the water through the sponge.

Pinacocytes-> layer of cells that provide an outer covering for the sponge, lines the internal chambers.

S & F continue

Archaeocytes-> resemble amoebasmove throughout the sponges body can form into any cell important in repair and regeneration transport food

Spicules->Skeletal elements that give support to

sponge’s bodyMade up of calcium carbonate, silica, or

sponging (protein that allows the sponge to be flexible).

More S & F

Body Forms of SpongesThree different typesThe folded body has evolved to

overcome the problem of water flow and surface area. The increased folds increase the surface area of the collar cells and reduce the spongocoel, which decreases the amount of water needed to be circulated. In the end it results in increased water flow and increased sponge growth.

Asconoid Syconoid Leuconoid

Simplest form

Clusters Tubular /

Small As it grows

the spongocoel increases.

First stages of body wall folding

Internal pockets of collar cells.

Highest degree of folding

Largest sponges

Pumps 5 gallons of water per day.

Feed on bacteria, plankton, and detritus

Suspension feeders-> feed on material that swims by.

Filter feeders-> filter food from the water.

Feeding

Food is engulfed and digested by pinacocytes and archaeocytes along the canal system-> carry them-> 80% of the food gets trapped by the collar cells-> flagellum strains the food by the current created by the beating tails-> draws water in through the ostia and expels it through the osculum.

How does the sponge do it?

Sexual and asexualBudding-> not common. Groups of

cells on the outer surface of the sponge develop and grow into tiny new sponges. When it gets to a certain size the sponge drops off and either floats away or establishes itself near the parent.

Fragmentation-> production of new cells that have been broken off by waves, storms, or predators.

Reproduction

Hermaphrodites- produce both male and female gametes.Sperm cells- form from modified collar cellsEggs- archaeocytes / collar cellsThe stimulus that initiates the production of

gametes = change in water temperature (photoperiod= amount of light / dark in 24 hours)

Sperm cells-> enters-> engulfed by collar cells-> both lose flagella-> collar cell transports sperm to the egg.

Amphiblastula- larval stage-> water column-> adult sponge

Reproduction continues

Biggest problem- finding a suitable place to attach. They compete with corals and bryozoans. Some produce chemicals that kill corals or inhibit growth

Boring Sponge – bores into corals and dead shells

Crabs use pieces of sponge as camouflage -> sponge grows on the crabs shell

Most are toxic to fish- few predatorsSea turtles eat them yummy HawksbillSymbiotic relationships:

Mutualism- cyanobacteria-> food / nutrients / protection

Commensalism- shrimp hide out in there until they are too big

Ecological Roles

Sponges

Glass Sponge

What eats a sponge?

Chitons

Marine Snails

Nudibranchs- Sea Slugs

Turtles

Fish

Sponges also Provide Homes

for Many Organisms, but which ones??

Sea anenomes

Octopus

Shrimp

Brittle Stars

Barnacles

Amphipods

Polychaete Worms

Copepods

http://www.youtube.com/watch?v=BW05vMziy2o

http://www.youtube.com/watch?v=T7E1rq7zHLc

http://www.youtube.com/watch?v=KOFFzXNYJG0

http://www.youtube.com/watch?v=mVavqt4Sbyo

Videos