Sponges- Filters of the SeaPhylum- PoriferaWhat they don’t have:

EyesOrgansCan’t move

SpongesWhy are they animals?

They are multi-cellular heterotrophsHave different cell types

SpongesThey range in size from a drop of paint to 16

feet acrossThey have 2 major cell types

1. Collar cells- have flagella that waft water into the sponges epithelium. (epithelium is the tissue that protects the sponge’s outer surface).

The epithelium has contractible pores through which water enters

2. Amoebocytes- are cells that pick up nutrient particles that pass through the sponges walls.

The amoebocytes are mobile cells that distribute nutrients throughout the sponge

Sponges

SpongesWater exits the sponge through oscula, large

openings to let the filtered water pass outBecause of the way they feed sponges are

considered filter feedersThe pores can get clogged with debris so

they have 2 ways to solve that problem1. They secrete large quantities of mucus to

cleanse their surface of debris and pathogens2. They provide a niche for mutualistic worms

and other organisms that feed on the material that can obstruct filtration

SpongesSponge larvae are free swimming organisms

with a flagella The larvae will swim and drift until colliding

with a suitable spot on the reef to fix themselves

Defense against predatorsSpicules are needlike structures in the tissueSpongin is a tough fibrous material that is

difficult to feed on. It is made of tough elastic protein

Many produce toxinsThey can reassemble if torn apart by a predator

Phylum- CnidariaInclude corals, anemones, sea fans, and jellyfishThey are radially symmetrical which means

they radiate around a central pointCnidarias have an internal sac for digestion

which is called the gastrovascular cavityThe gastrovascular cavity has only one opening,

a mouth, through which the animal takes in food and releases waste

Tentacles radiate outward from the rim of the mouth.

CnidariansThe body wall of a cnidarian consists of three

layers, an outer layer known as the epidermis, a middle layer called the mesoglea, and an inner layer referred to as the gastrodermis

Epidermis contains a collection of different types of cells forContracting and enabling movementProduction of sperm and eggContaining stinging structuresMucus-secreting cells Receptor and nerve cells which collect and

transmit sensory information

CnidariansMesoglea is a jelly layer

Jellyfish

JellyfishJellyfishes require water to help support their

body and if removed from their aquatic surroundings, they collapse and die.

To move forward, jellyfishes take water into their muscular bell and then squirt it out behind them, creating a jet of water

Jellies also drift on water currents to moveTheir senses are primitive and consist of a

neural net, eye spots that can sense light from dark, and chemosensory pits that help them identify potential prey.

JellyfishNematocysts consist of a capsule that holds a

hollow barbed coil, a venom sac, and chemo-sensitive trigger hairs that detect when something edible brushes against them. When potential prey brushes against the trigger hairs, the nematocysts expel the coiled barb and inject venom into the victim through the hollow thread. The venom immobilizes the prey and the jellyfish uses its oral arms to move the prey into its mouth

JellyfishLifespan-Jellyfish evolve from a dimorphic (two-

shaped) cycle. The two body forms are the asexual polyp and the sexual medusa. The male in the medusa form releases sperm from its mouth into the water and some of the sperm will enter into the female's mouth. Fertilization takes place in the female's mouth and the eggs will remain there until they develop into larvae. The larvae will leave the mother, drift through the water and settle on the floor. They are now called polyps. Polyps reproduce asexually by budding. The buds, which resemble a stack of saucers, are individual "baby" jellyfish called ephyra that separate from the polyp and drift in the water. After a few weeks, the cycle is complete when the ephyra grows into an adult or medusa.

DietJellyfish eat a variety of food, some that are too

small for the human eye to see. They eat small plants, fish and crustaceans, fish eggs and even other species of jellyfish.

PredatorsPredators include sea turtles, spade fish and

sunfish. In Asia, certain jellyfish are consumed by humans and are considered a delicacy which brings in millions of dollars.

CoralsThe marine creatures who form coral reefs

and atolls are called coral polyps and they could be as minute as 2.5 centimeters in diameter, while some measure up to 30 centimeters in diameter.

As tiny as they are, they have a mouth-like opening that is surrounded by even tinier tentacles.

The other end is equipped with natural substances allowing these polyps to attach their body to the ocean floor.

As living creatures, they feed on the larvae of shellfish, but they subsist largely on algae

The algae exist right in the polyp’s own tissues. While attached to the polyp, the alga secretes

chemical nutrients that enable the coral animals to form external limestone skeletons and develop color.

The algae require sunlight in order to photosynthesize This requires the corals to grow in shallow, clear,

well lit water

As host to the algae, the polyp tends to assume the alga's color as a living organism.

Another vital substance needed by coral animals to develop their external skeletal formations are the calcium intakes they get from seawater

Some polyps live singly but most of them form into a community by attaching to each otherThese are the reef building corals and are

often found in the shallower portions of warm tropical seas

StarfishSea stars belong to the Phylum

EchinodermataThat means they are related to sand dollars,

sea urchins, and sea cucumbers All echinoderms have five-point radial

symmetry, which means that their body plan has five sections (or multiples thereof) arranged around a central disk

There are about 2,000 species of sea stars and are found everywhere in the oceans

Not all sea stars have 5 arms. Some have many more. The sun star has up to 40 arms!

Sea stars can regenerate lost armsIf the sea star is threatened by a predator - it

can drop an arm, get away and grow a new arm

Sea stars house most of their vital organs in their arms, so some can even regenerate an entirely new sea star from just one arm and a portion of the star's central disc.

It takes about a year for an arm to grow back

Protection-Sea stars have a tough covering on their upper side, which is made up of plates of calcium carbonate with tiny spines on their surface.

Predators-include birds, fish and sea ottersMovement- tube feet help it to move but

very slowlyPrey-They prey on bivalves like mussels and

clams, as well as small fish, snails, and barnacles.Sea stars wrap their arms around the animal's

shell and pull it open just enough. It pushes its stomach through its mouth and into the bivalve's shell. It then digests the animal and slides its stomach back into its own body

Vision-sea stars have an eye spot at the end of each arm. This is a very simple eye that looks like a red spot. The eye doesn't see much detail, but can sense light and dark.

Reproduction-Sea stars may reproduce sexually or asexually. There are male and female sea stars, but they are indistinguishable from one another. They reproduce by releasing sperm or eggs into the water, which, once fertilized, become free-swimming larvae that later settle to the ocean bottom.