BIOLOGICAL DIVERSITYWhere do the rights of one specie start and the other ones end?

VERTEBRATES

ANIMAL DIVERSITY

WHAT IS A VERTEBRATE?

Animals with an internal skeleton made of bone are called vertebrates. 

Vertebrates include fish, amphibians, reptiles, birds, mammals, primates, rodents and marsupials

VERTEBRATES TRAITS

The traits that makes them so special are the spinal cords, vertebrae, and notochords. It's all about having a series of nerves along your back (dorsal side). If you are an organism, you can't just have the nerves sitting there. You need to give those nerves support and protection. That need brings us to the backbones and a rod of cartilage called the notochord. 

CLASSIFICATION

Subphylum

Vertebrata

Class Agnatha (jawless fishes)

Class Chondrichthyes (cartilagin

ous fishes)

Class Osteichthyes (bony

fishes)

Class Amphibia (amphibians)

Class Reptilia (reptiles)

Class Aves (birds)

Class Mammalia (mammals)

CLASS AGNATHA Agnatha  is a group of vertebrates that lacks a jaw. The oldest fossil agnathans appeared in the Cambrian,

and two groups still survive today: the lampreys and the hagfish, comprising about 120 species in total.

Lampreys have a light sensitive pineal eye. Fertilization and development are both external. There

is no parental care in the Agnatha class. The Agnatha are ectothermic or cold blooded, with

a cartilaginous skeleton, and the heart contains 2 chambers.

Lampetra fluviatilis

Astraspis desiderata

CLASS CHONDRICHTHYE

Also known as cartilaginous fishes are jawed fish with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone.

The class is divided into two subclasses: Elasmobranchii (sharks, rays and skates) and Holocephali (chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class).

Carcharodon carcharias

CLASS CHONDRICHTHYE The skeleton is cartilaginous.

Their tough skin is covered with dermal teeth.

All Chondrichthyes breathe through 5-7 gills, depending on the species.

Fertilization is internal. Development is usually live birth (ovoviviparous species) but can be through eggs (oviparous).

CLASS OSTEICHTHYES 

Endocondral bones form the

skeleton

Even and odd fins

With jaws, ussually with

teeth

Breathing by gills and covered by the opercule

Swim bladder

Circulatory system with a

heart, with atrium and

ventricle without separation

Excretory system with

kidneys adapted to different

environments

Nervous system with small brain,

olfatory and optic lobes

CLASS AMPHIBIA

Resilient skeletal structure with

tetrapod appendix

Respiratory system with lungs and a pair of internal

nostrils

Double circulation with pulmonary

and systemic, heart with 3 chambers

The ear gets a timpanic

membrane

The cornea becomes the responsible

structure for light refraction, they

developed eyelids and lacrimal

glandules

MODERN AMPHIBIANS

Bone skeleton, with vertebraes, ribs, no exoskeleton.

Great diversity of shapes and forms.

2 pairs of extremities (tetrapods), with generally 4 fingers per anterior leg

Smooth and wet skin with many glandules.

Normally big mouth, with small teeth in the superior jaw, 2 nostrils that open in the back of the mouth.

Respiration by lungs and skin, independently or combined.

Trichamber heart circulation.

Ectothermics.

Separated genders with internal fecundation in salamanders and external in frogs and toads.

Oviparous, ovoviviparous and viviparous.