Survey of Invertebrates and Vertebrates

The subphylum Vertebrata includes all of the familiar large animals and some rare and unusual ones as well. The 7 living classes of vertebrates are distinguished mostly on the basis of their skeletal system, general environmental adaptation, and reproductive system.

Agnatha

• Three of the vertebrate classes are fish. The most primitive of these is Agnatha . It consists of jawless fish that do not have scales. These are the lampreys and hagfish.

Chondrichtyes

• Fish that have skeletons consisting of hard rubber-like cartilage rather than bone are members of the class Chondrichthyes.

• These are the sharks and rays.

Osetiechtyes

• All of the bony fish are members of the class Osteichthyes . Tuna, bass, salmon, and trout are examples of Osteichthyes.

Amphibia

• Animals in the class Amphibia spend part of their lives under water and part on land.

• Frogs, toads, and salamanders are amphibians. • Many of these species must keep their skin moist by

periodically returning to wet areas. • All of them must return to water in order to

reproduce because their eggs would dry out otherwise. T

• They start life with gills, like fish, and later develop lungs to breathe air.

Reptilia

• The class Reptilia includes turtles, snakes, lizards, alligators, and other large reptiles.

• All of them have lungs to breathe on land and skin that does not need to be kept wet.

• They produce an amniote  egg which usually has a calcium carbonate rich, leather hard shell that protects the embryo from drying out.

• This is an advantage over fish and amphibians because the amniote egg can be laid on land where it is usually safer from predators than it would be in lakes, rivers, and oceans.

Aves• The class Aves includes all the birds. • They also produce amniote eggs but usually give them

greater protection from predators by laying them high off of the ground or in other relatively inaccessible locations.

• In the case of both reptiles and birds, the eggs are fertilized within the reproductive tract of females.

• There are other striking similarities between reptiles and birds in their anatomies and reproductive systems.

• This is not surprising because birds are descendants of theropod dinosaurs (two-legged mostly carnivorous dinosaurs).

Mammalia

• Dogs, cats, bears, humans and most other large animals today are members of the vertebrate class Mammalia .

• All mammals conceive their young within the reproductive tract of the mother and, after birth, nourish them with milk produced by their mammary glands .

• Like birds, mammals are endothermic , or warm blooded. They are able to maintain a relatively constant body temperature regardless of external environmental conditions mainly by using internal physiological mechanisms.

Invertebrates

• Kingdom: Anamalia

Phylum Arthropoda• 1. Exoskeleton containing chitin • 2.Body bilaterally symmetrical • 3.Body segments grouped into specialized regions • 4.Jointed appendages • 5. These jointed appendages variously specialized for feeding,

locomotion, sensing

Class Crustacea

• Order Decapoda : Lobsters, crayfish, crabs, shrimp

• Order Isopoda:Sowbugs, pillbugs, roly-polys

Class Insecta

• Such as butterflies, fleas, and beetles

Class Chilopoda

• Centipedes

 Class DIPLOPODA

• Millipedes

Class ARACHNIDA

• Order Araneae: spiders

• Order Acari: mites and ticks

• Order Scorpiones: scorpions

Phylum Porifera

• Class: Demonspongiae– Bath sponge

Phylum Cnidaria

• Class Hydrozoa: Hydra• Class Scyphozoa: Jellyfish• Class Anthozoa: Sea Anemones, Coral

Phylum Platyhelminthes-(flatworms)

• Bilateral symmetry.• Acoelomate.• hermaphroditic.• One opening into gastovascular cavity.• With cephalization forming a primitive brain

and a ladder type nervous system.

Class Turbellaria

• Planarian: Free-Living

Class Trematoda

• Flukes:– 1. All parasitic.– 2. with suckers.– 3. Specialized reproductive systems and a

complex life history.

Class Cestoda

• Tapeworms– 1. All endoparasites.– 2. Head containing hooks and suckers.– 3. Body made up of segments called proglottids

each containing reproductive organs.– 4. No digestive system/

Phylum Nematoda (Round worms)

• Chracteristics1)Bilaterally symmetrical2)Body has more than two cell layers, tissues and organs. 3)Has no circulatory system (no blood system) 4)Reproduction normally sexual and5)Feed on just about everything. 6)Live just about everywhere, many species are endoparasites.

• Example: Ascaris

Phylum Rotifera

• Bilaterally symmetrical• A mouth, complex jaw, muscular pharynx, and

posterior anus• Epidermis with a fixed number of nuclei• Separate sexes, males are dwarf, and rare or

absent

Phylum Mollusca

• A Mollusk has bilateral symmetry.• A Mollusk is either male or female and reproduces sexually with a large organ called a gonad.

• A Mollusk has an outer shell. It has a soft body. It has a muscular foot that it uses for movement.

Class Gastropoda

• This class includes snails and slugs. • Gastropods are primarily marine, but some

species also inhabit freshwater and terrestrial habitats.

• In all forms, the visceral mass is located enclosed in a coiled shell during early developmental stages.

Class Bivalvia

• Members of this class are characterized by a shell consisting of two valves or halves.

• Bivalves use a muscular foot for locomotion.• Siphons are used to draw in a stream of water

which is passed over the gills for feeding and respiratory purposes.

• Examples: Clams, Oysters

Class Cephalopoda

• The cephalopods are considered to be the most highly evolved class of molluscs.

• These organisms have a highly evolved visual system, and tentacles with suction cups.

• They are all marine, and are active predators.• Examples: Squid, Octopus

Phylum Annelida

• The phylum Annelida (segmented worms) is diverse, containing the earthworms, leeches, and marine worms.

• Have Bilateral Symmetry.• A complete digestive tract,• A nervous system showing some degree of

cephalization,• A closed circulatory system,• An excretory system

Class Polychaeta

• Mostly marine worms, such as the clamworm

Class Hirundinea

• Class Hirudinea - the leeches (predominantly freshwater)

Class Oligochaeta

• Mostly freshwater and terrestrial worms, such as earthworms

Phylum Echinodermata

• Echinoderms have radial symmetry• Have five or multiples of five arms. • They have a shell, made mainly of calcium

carbonate, which is covered by skin.

Class Asdteroidea

• Sea Stars

Class Ophiuroidea

• Brittle Stars

Class Echinoidea

• Sea Urchins

Class Holpthuriodea

• Sea Cucumbers