k. Animalia 1

Kingdom AnimaliaPhylum: Annelida

Pg 672-735

k. Animalia 2

P. Annelida- Annelids

• 15000, species of segmented worms• Bilaterally symmetrical• True coelom, divided into parts, one segment

disabled other functions• Setae (SEET-ee) external bristles• Parapodia – fleshy protrusionsDivide into three classes based on parapodia1. Oligochaeta (AHL-uh-goh-KEET-uh)2. Polychaeta – (PAHL-i-KEE-tuh)3. Hirudinea- (HIR-yoo-DIN-ee-uh)

k. Animalia 3

Class Polychaeta

• 2/3 of all annelids are members

• Many bristles, help move

• They have antennae and mouthparts

• Marine habitats

• Strong jaws (predators) eat small animals

• Feed on sediment as they burrow

• Or use tentacles to search ocean floor

k. Animalia 4

Class Hirudinea• Smallest class of annelids• 500 species of leeches• Fresh water, moist vegetation on land• No setae or parapodis• Has sucker that attaches to surfaces- movement• Ability to swim• Carnivores, small invertebrates (parasites)• Secret an anesthetic prevents host from feeling• Secret substances that prevents blood clotting• Ingest 10xs its own weight

k. Animalia 5

Class Oligochaeta

• “few bristles” and few setae on segment

• Live in soil or fresh water

• Have no parapodia

• Earthworm

• Adaptations that enable this animal to a burrowing life?

k. Animalia 6

Class Oligochaeta cont.1. Structure and movement

- divided into more than 100 segments- circular and longitudinal muscles- movement possible by segments, slinky

2. Feeding and digestion- ingest soil as they burrow, sucked into mouth by the muscular pharynx passes down the esophagus to the crop to the thick muscular part called the gizzard anus

Role is to decompose dead leaves and other organic materials release nutrients into the soil

Loosen the soil for plantsAllow air to penetrate into the soil

k. Animalia 7

Class Oligochaeta cont.

3. circulation- closed system

blood goes toward the posterior end by a ventral blood vessel and then to the anterior end by the dorsal blood vessels

Five muscle tubes, aortic arches- link the dorsal and ventral blood vessels near the anterior end of the worm

k. Animalia 8

Class Oligochaeta cont.

4. Respiration and excretion

Gas exchange goes directly through the skin

Only if the skin is moist

Nephridia-excretory tubules that helps eliminate cellular wastes and excess water

Other wastes are released from the body by pores on the ventral surface

k. Animalia 9

Class Oligochaeta cont.5. Neural ControlChain of ganglia connected by the ventral nerve cordCerebral ganglia- process info from sensory

6. Reproduction- hermaphrodites, but can not fertilize its own egg

Mating occurs when two worms press ventral surfaces together with anterior ends pointing in opposite directions, they are held together by the setae and film from clitellum (thick middle)

Sperm is secreted in the mucus and is stored in the seminal receptacle to be later used to fertilize the egg

Baby takes 2-3 weeks before hatching

k. Animalia 10

P. Mollusca- “soft”• Clams, snails, slugs, and octopuses• Soft bodies and hard shells• 112,000 species• Sedentary filer feeders and fast moving

predators• Complete nervous system• Coelomates- true coelom (hollow fluid-

filled cavity surrounded by mesoderm)• Trochophore- larval stage, free-swimming

k. Animalia 11

Body planDivided into 2 regions:

1. head-foot- 2. visceral mass- contains the heart and organs of digestion, excretion, and reproduction

TERMS:Mantle- layer of epidermis that covers the visceral mass, secrets

calcium carbonate (shells)Gills- gas exchangeMantle cavity- space between the mantle and visceral massDo not have segmentated bodiesBilaterally symmetrical Ganglia- cluster of nerve cellsRadula- feeding adaptation, flexible tongue like strip of tissue covered

with tough, abrasive teeth that point backwards(cut leaves, scrape algae, drill other snails)Use structural differences to divide mollusks into seven classes1. Gastropoda 2. Bivalvia 3. Cephalopoda

k. Animalia 12

Class Gastropoda• “stomach” and “foot”

• Largest and most diverse (40,000 species)

• Snails, abalones, conchs- single shell

• Slugs and nudibranchs- have no shell

• Torsion- larval development

• Open circulatory system

(gills heart tissues)

k. Animalia 13

Class Bivalvia• Aquatic mollusks, clams, oysters, scallops• Bivalves- have shells that can be divided in half,

connected by a hinge• Adductor muscles are attached to the inside surface of

each valve, when it relaxes the valves opensEach valve has 3 layers that are secreted by the mantle

1. thin outer layer- protection from outside environment2. thick middle layer- strengthen the shell3. smooth shiny inner layer – protects soft body

Sessile and filter feeders (No Radula)Lack a distinct head3 sets of ganglia:

1. mouth 2. digestive system 3. footSome have small eyes on mantle edge (sensory structures)

k. Animalia 14

Clams- Bivalves• Mud or sand

• Siphons- hollow tubes

• Cilia on gills – sends water to Incurrent siphon excurrent siphon, water circulates inside clam (trap food)

• Separate sexes

• Shedding sperm and eggs in water fertilization is external (trochopore)

k. Animalia 15

Class Cephalopoda• Octopuses, squids, cuttlefishes, chambered nautiluses• “head-foot”• Free-swimming, predatory • Tentacles- with suction cups• Jaws that look like parrots beak• More advanced nervous system• Closed circulatory system• Male transfers sperm to female mantle cavity with

tentacles• Develops from an egg to juvenile (no trochopore)• Chromatophores- dark fluid for distractions

k. Animalia 16

P. Echinoderms (spiny skin)

• Sea stars, sand dollars, sea urchins, and sea cucumbers

• Shallow coastal waters 10,000 m deep• Vary in size• Bright colors• Radially symmetrical• No head or cephalization• Have a bilateral symmetry larva• Deuterostomes – (anus first)

k. Animalia 17

4 major characteristics1. Radial symmetry called pentaradial- body parts

extend from the center along five spokes

2. Endoskeleton composed of calcium carbonate plates known as ossicles

3. Water-vascular system- network of water0filled canals inside their body

4. Small movable extensions of the water-vascular system called tube feet – they aid in movement, respiration, feeding, excretion

k. Animalia 18

Classes 1. C. Crinoidea- kri-NOYD-ee-uh “lily-like”, sea lilies, feather stars

2. C. Ophiuroidea- OH-fee-yoor-OYD-ee-uh “snake tail” basket stars and brittle start, largest class

3. C. Echinoidea – EK-uh- NOYD-ee-uh “spin like” sea urchins and sand dollars, have ridged exoskeleton called a test

4. C. Holothuroidea- HOH-loh-thuh-ROYD-ee-uh “water polyp” sea cucumbers

5. C. Asteroides AS-tuh-ROYD-ee-uh “star like” sea star or starfish** economically important because they feed on oysters, clams (human food)

k. Animalia 19

Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish

1. External structure- – composed of several arms (5- 24)– Two rows of tube feet under each arm– Body is flattened– Oral surface- mouth side, under side– Aboral surface – opposite to mouth side– Covered with short spines– Tiny pincers called pedicellariae, keep it free

from of foreign objects

k. Animalia 20

Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish

2. Water-Vascular System-Net work of water-filled canals that are connected

to the tube feeta. Water enters through pores in the madreporite

(sieve-like plate on aboral surface)b. Water passes down the stone canal- tube that

connects the madreporite to the ring canal (encircles the mouth)

c. Radial canal carries water to the tube feet (valves keep it from flowing back up)

d. Ampulla- sacs on feet contract forcing water into the feet

k. Animalia 21

Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish

3. Feeding and digestion

a. mouth short esophagus cardiac stomach ( can turn inside out through its mouth when it feeds) pyloric stomach (connects to a pair of digestive glands in each arm) nutrients are absorbed into the coelom by walls of digestive cavity and excess is excreted by anus on aboral surface

b. they are carnivores, mollusks, worms

k. Animalia 22

Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish

4. Other body systems

a. no circulatory, excretory or respiratory organs

b. gas exchange and waste excretion by diffusion in walls of tube feet and skin gills

c. no head and no brain

d. have a nerve ring and radial nerves

e. nerve net and touch-sensitive cells

k. Animalia 23

Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish

5. Reproduction and developmenta. separate sexesb. each arm has a pair of ovaries or testesc. 200 million eggs in one yeard. external fertilization- e. fee-swimming larva bipinnariaf. 2 months metamorphosis g. regenerate arms, long time

k. Animalia 24

P. Arthropoda “jointed foot”• Segmented animals• Appendages• Exoskeleton (protection and support)• High degree of cephalization• Compound eyes- has many light detectors• All have open circulatory system• Molting- sheds its exoskeleton and make a new one• Divided into five subphyla on basis of differences in

development and in the structure of appendages 1. Trilobita 2. Crustacea 3. Chelicerata 4. Myriapoda 5. Hexapoda

k. Animalia 25

Subphylum Crustacea

• 38,000 known species, vary in size• Ocean, lakes, rivers, and land • Some sessile, some have legs, swim• Have two pairs of antennae• Pair of jawlike chewing mouthparths (mandibles)• Skin to gills for respiration• Embryo becomes a free-swimming larva called a

naupius

k. Animalia 26

Crayfish• Order Decapods “ten feet”• Have five pairs of legs – locomotin1. External structure-

a. two major sections- 1. abdomen- 6 segments2. cephalothorax-head(5)thorax(8)

Tagmata- segments fused together to make one larger structureb. antennae- 2 pairs, feelers, tastec. chelipeds- back legs with pinchersd. swimmerets- create water currents and function in reproductione. telson/uropods- posterior end is paddle like tail

k. Animalia 27

Crayfish cont:2. digestion- esophagus to stomach where

teeth grind food into paste and the digestive glands secret enzymes for digestion and absorption extra exits anus

3. respiration- feather like gills, as it walks legs circulate water across gills

4. circulation- open circulatory system

k. Animalia 28

Crayfish cont:

5. Excretion- water is removed by excretory organs called the green glands

dilute fluids are excreted by a pore at the base of the antennae

6. Neural control/ sensory organs- similar to annelids

Have pair of ganglia, sense vibration and chemical in water by sensory hairs, compound eye