Ctenophora

1. Biradial symmetry Tentacles with colloblasts (discharge sticky filament) Uses comb plates, or plates of cilia, for mobility (unique) Ctenophora Ctenophora • Gastrovascular cavity: canal system and one or more anal pores • No coelom • Germ layers: ectoderm and endoderm (with mesoglea in between- this is up for debate) “Tortugas Red” (still unnamed)

2. Mesoglea is a jelly like substance that makes up most of the organism and forms structural support • Digestion is extracellular. Breakdown products are distributed via branches of the gastrovascular cavity. Undigested food is expelled through mouth and anuses. • Digestive system includes a “pharynx” of folded epidermis. • Sexual, external reproduction (although has great regeneration powers) – mostly hermaphrodites • Lack the polyp-medusa life cycle found in Cnidaria

3. Most have no nematocysts • Lack the polyp-medusa life cycle found in Cnidaria • Lack cnidocytes found in Cnidaria • Nerve net: form nerve-like strands beneath the comb cells • Unique structure: statocysts. Used for balance and movement (much like a flagellum) – serves as the body’s main sense organ

4. Organisms • Pleurobranchia (sea goosebery) • Beroe • Bathocyroe fosteri • Larva of Bolinopsis

5. Interesting Facts • In a few species, special cilia in the mouth are used for biting gelatinous prey. • The opening of the mouth is able to seal up like a zip-loc bag once the prey is inside. • Ctenophores can live in depths of up to 4 km! • “Ctenophore” in Greek means “comb-bearer”

6. Ctenophore Movement • Movie of Beroe Ctenophore

7. Cnidaria

8. Radial Symmetry • Two germ layers (ectoderm and endoderm) • No Coelom • Blastopore does not go all the way through and it has no anus • The Gastrovascular cavity is also called the coelenteron • Movement is coordinated by a simple network of nerves • Have Tentacles that get the food to their central mouth • They use jet propulsion

9. Reproduction/Life Cycles • Cnidarians reproduce both sexually and asexually. They reproduce asexually by budding. The bud will eventually fall off the parent organism and becomes a new polyp. Some cnidarians reproduce sexually by releasing egg and sperm into the water. They (the eggs) will be fertilized by sperm and develop into a larva called planula. The planula will then develop into a new polyp which will produce new medusas called ephyra. Medusa body types of cnidarians have both a sexual and asexual stage. The stages alternate. Medusa reproduce sexually to produce polyps, which will grow up and reproduce new medusa.

10. Specialized Tissues • Has an outer wall, epidermis, specialized and complex • Contains Sensory cells and nematocysts (also called cnidocytes) that are defense • Inside is the mesoglea which is a jellylike substance that supports the jellyfish

11. Portuguese Man of War Colonies • The Bluebottle or Portuguese Man-of-War is not a single animal but a colony of four kinds of highly modified individuals (polyps). The polyps are dependent on one another for survival. • The float (pneumatophore) is a single individual and supports the rest of the colony. The tentacles (dactylozooids) are polyps concerned with the detection and capture of food and convey their prey to the digestive polyps (gastrozooids). Reproduction is carried out by the gonozooids, another type of polyp.

12. Coral Reefs • Grow in low nutrient waters • High nutrients encourage the growth of algae which harms reef • Many individual coral organisms that secrete calcium carbonate which is the hard structure that makes up the reef • A coral reef supports many different life forms

13. Anthoazo Hydrozoa Scyphozoa Conulata Cubozoa

14. Porifera

15. Porifera • Sponges can be either radiallysymmetrical or asymmetrical • Sponges have three different body plans • * Asconoid sponges are shaped like a simple tube perforated by pores. The open internal part of the tube is called the spongocoel; it contains the collar cells. • * Syconoid sponges tend to be larger than asconoids and have a tubular body with a single osculum. The synconoid body wall is thicker and the pores that penetrate it are longer, forming a system of simple canals. These canals are lined by collar cells, the flagellae of which move water from the outside, into the spongocoel and out the osculum. • *The third category of body organization is leuconoid. These are the largest and most complex sponges. These sponges are made up of masses of tissue penetrated by numerous canals.

16. Porifera • Water movement is driven by the beating of flagellae, which are located on specialized cells called choanocytes (collar cells) • Adult sponges are generally assumed to be completely sessile, but a few studies have shown that adult sponges in a variety of species can crawl slowly. • Reproduction by sponges is by both sexual and asexual means. Asexual reproduction is by means of external buds. Sexual reproduction takes place in the mesohyl. Male gametes are released into the water by a sponge and taken into the pore systems of its neighbors in the same way as food items. Spermatozoa are "captured" by collar cells, which then lose their collars and transform into specialized, amoeba-like cells that carry the spermatozoa to the eggs. Some sponges are monoecious; others are dioecious. In most sponges for which developmental patterns are known, the fertilized egg develops into a blastula, which is released into the water. The larvae may settle directly and transform into adult sponges, or they may be planktonic for a time. • A spongocoel is a large central cavity of sponges. Water enters into the spongocoel through hundreds of tiny pores (Ostia) and exits through the larger opening (osculum).

17. Porifera Anatomy

18. Examples of Porifera Stove Pipe Sponge Hard Coral Purple Tube Sponge

19. Porifera Fun Facts • Poriferans don't have mouths; instead, they have tiny pores in their outer walls through which water is drawn. • Water flowing through sponges provides food and oxygen, as well as a means for waste removal. • Many times of poisonous porifera have been found in oceans • In 1997, use of sponges as a tool was described in Bottlenose Dolphins in Shark Bay. A dolphin will attach a marine sponge to its nose, which is presumably then used to protect it when searching for food in the sandy, and sometimes rough sea bottom. • Porifera are also used by cosmetic companies to make lufas and bath sponges

20. Review • What is a spongocoel? • Explain briefly how a sponge reproduces • What kind of symmetry do sponges have? • Describe two types of sponges • What Group has biradial symmetry? • What Group includes the Portuguese Man of War? • Which group has cilia in their mouth to bite gelatinous prey