Sponges Phylum Porifera and Cnidarians By Brie Clark

Sponges (Phylum Porifera) and Cnidarians By: Brie Clark

Sponges • )No definite symmetry. 2)Body multicellular, few tissues, no organs. 3)Cells and tissues surround a water filled space but there is no true body cavity. 4)All are sessile, (live attached to something as an adult). 5)Reproduce sexually or asexually, sexual reproduction can be either gonochoristic or hermaphroditic. 6)Has no nervous system. 7)Has a distinct larval stage which is planktonic. 8)Lives in aquatic environments, mostly marine. 9)All are filter feeders. 10)Often have a skeleton of spicules.

Sponges • Sponges live • permanently connected to one spot in the water Sponges have two layers on their body – Acellular (having no cells) – Mesohyl (gel layer)

Sponges Cont. • Sponges have three different types of body plans – Asconoid= Sponges look more like a tube and perforated by pores – Syconoid= Sponges are bigger than Asconiod, only one opening to the outside – Leuconoid= Biggest and most complex, water moves through

Sponges Cont. • There are 5, 000 to 10, 000 know species of sponges • Most sponges live in salt water, and only about 150 live in fresh water • They say that sponges evolved over 500 years ago

Glass Sponges • Glass sponges were know to be extinct – Found recently • Glass sponges made • • out of silica They help build the reef Found in protected Canadian waters

Glass Sponges Cont. • Are now found in many parts of the ocean. – Different than the ones that build on the reef

Cnidaria • Cnidaria includes: – Sea anemones, corals, jellyfish, sea pens, hydra • Sea anemones= considered to be the flower of the sea – Look like plants, eat meat – Attaches to rock and coral – Usually stay in one spot whole life

Cnidarians • They are radially symmetrical • Medusa is a free swimming structure • The medusa layer is thick and jelly-like – Most associated with jelly fish • Some cnidarians only show the medusa stage throughout their life • Others first pass through other stages before maturing into the medusa form

Jelly. Fish • Jellyfish have reproductive parts called gonads – Just like humans • Males produce sperm • Females produce an egg • Tentacles of a jellyfish have cnidocytes embedded in them – They are specialized cells • No other organism has them

Sea Pen • Looks like an old-fashioned quill pen – Colors • Dark orange • Yellow • White • Colony of polyps – Work together to live v. A polyp is a sessile that attaches to the sea floor and forms large sea colonies • Some cnidarians stay a polyp for their whole life

Sea Pens Cont. • Predators – Red Star – Leather Star – Nudibranchs (Sea Slug) • Sea Pens are octocorals – They each polyp has eight tentacles – Glow with light green light • When Attacked – Force out water – Retreat to its bulbous foot

Sea Pens Cont. • The “branches” catch plankton • Some polyps reproduce • Others force water in and out to ventilate the colony • Popular in Puget Sound/population decreasing

Hydrozoa • Hydra in the phylum Cnidaria – They are a fresh water animal (Ponds and Ditches) • Hydrozoa spend some of their life as a jellyfish • The Hydra never go through medusoid stage • They have three structural features – Body built of 2 layers – Contain 1 internal cavity – All cells produced in the 1 st or 2 nd layer • A third one isn’t made (Like an embryo)

Cnidarian Life Cycle

Sea Anenome • The flower of the sea • Look like plants – Eat meat • They spend most of their lives in one place – Bury themselves into mud – Or attach to rocks • Travel

Sea Anemone • Attach to rocks or • coral Have a central mouth – Surrounded by tentacles • They wait for food to swim by

Sea Anemone Cont.

Hitchhikers • Sometimes they ride on a hermit crab, or decorator crabs • Sea Anemone can protect the crab – Eat left over food if lost • Some Anemones just float around in the water