UNIT 5: VERTEBRATE ANIMALS

UNIT 5: VERTEBRATE ANIMALS

1. GENERAL CHARACTERISTICS

   • Vertebrates are multicellular, eukaryotic, heterotrophic organisms that have a backbone (spinal column) is made of articulated segments of bone known as vertebrate.
   • The body structure of a vertebrate
     • -Has bilateral simmetry and is divided into three parts: head, trunk and tail. -The body is covered in skin. It can also have different types of associated glands. -All have internal skeleton made up of a skull and a backbone. REGULATION OF BODY TEMPERATURE Fish, amphibians and reptiles are ecotherms. Create very little of their own body heat and relyon heat from their enviroment to regulate their body temperature. Birds and mammals are endotherms. Mantain a constant internal temperature.
   • Vital functions of vertebrates
     • NUTRITION: have a complete digestive system. There are herbivores, carnivores, omnivores and also filter-feeders. Breathe through gills or lungs. Some also breathe through their skin. For example in frogs the larvae breathe through gills, whereas the adults do it through lungs. REPRODUCTION: Reproduce sexually and most have separate sexes, except some fish species which are hermaphrodites. Vertebrates can be oviparous (lay eggs), ovoviviparous (eggs develop inside the mother´s body until they are ready to be hatched) or viviparous (the embryo develops into a young animal inside the mother´s body).  Oviparous: female lay eggs in the open environment which reduces the chances of survival for the offspring. Viviparous: the pprtection of the embryo inside the mother body increases the chances of survival for the young. INTERACTION: nervous system is made  up of a spinal cord, which runs along the animal´s back, and a highly developed brain, located in the head. CLASSIFYING VERTEBRATES Fish: verebrate with gills, scales and fins. Birds: vertebrates with feathers, beaks and wings. Amphibians: vertebrates with a soft skin and four legs. Reptiles: vertebrates with a hard skin covered in scales and four legs. Mammals: vertebrates with four limbs and mammary glands.

2. FISH

   • Are aquatic animals that live in marine and freshwater environments. Have a fusiform body with fins that help them to swim. the body is covered in scales. The body of a fish is divides into a head, trunk and tail.
   • VITAL FUNCTIONS OF FISH
     • NUTRITION: Some are carnivores others herbivores or omnivores. Larvae are usually filter-feeders. Fish breathe through gills. Are protected by a operculum or gill cover. REPRODUCTION: have separated sexes. Most are oviparous and their fertilisation is external. Sharks and rays use internal fertilisation.  INTERACTION: Have a sense organ called a lateral line. This runs along eachs side of the body and detects changes in water pressure or the presence of prey or predators.
   • CLASSIFYING FISH
     • CHONDRICHTHYES: such as rays and sharks have a flexible skeleton of cartilage. their skin is covered in denticles. OSTEICHTHYES: such as perch, cod and trout have a rigid bony skeleton. Most have smooth skin with thin transparent scales.

3. AMPHIBIANS

   • Some spend most of their lives in water while others are wholly terrestial and only return to the water for reproduction. Here body is saparated in skin head and legs. ANURANS: have no tail in their adult stage. Their hind legs are twice as long as their front legs. URODELES: have an elongated body and a tail in their adult stage. Their front and hind legs are the same lenght.
   • VITAL FUNCTIONS OF AMPHIBIANS
     • NUTRITION: adults are carnivores, whereas larvae are herbivores. When amphibians are at their larval stage, they are completely aquatic and breathe through gills. When they get to the adult stage they breathe through lungs. REPRODUCTION: Has separated sexes. Fertilisation can be external or internal. Most are oviparous and always lay their eggs in water.  INTERACTION: frogs and toads have vocal chords. Play a sound that play an inportant role in the reproduction.

4. REPTILES

   • Where the first vertebrates that completely adapted to living on land.  Her body is separated in scales, tail, trunks and head.
   • VITAL FUNCTIONS OF REPTILES
     • NUTRITION: most are carnivores. Some are herbivores. Most have teeth. All breathe using lungs. REPRODUCTION: have separated sexes and internal fertilisation. Most are oviparous.
   • CLASSIFYING REPTILES
     • CHELONIANS: have a hard beak with no teeth and a external shell. LIZARDS: have four legs and a tail. OPHIDIANS: have long elongated bodies with no legs. CROCODILES: have strong jaws and powerfull teeth.

5. BIRDS

   • Are vertebrates with an aerodynamic body and wings, even though not all of them are able to fly. Her body is separated in beak, wings, tail, legs and feathers.
   • VITAL FUNCTIONS OF BIRDS
     • NUTRITION: the digestive system includes a grinding organ. Birds breathe using small lungs. These have extensions filled with air which help maintain high levels of oxygen-rich air in the respiratory system. REPRODUCTION: reproduce using internal fertilisation and are oviparous. INTERACTION: have very well developed vision.
   • CLASSIFYING BIRDS
     • OSTRICHES AND PENGUINS: can´t fly. ANSERIFORMES: webbed feet. FALCONIFORMES: birds of prey. GALLIFORMES: CICONIIFORMES: long necks and legs. PASSERINES: over half of all birds over the world.

6. MAMMALS

   • Are vertebrates whose offspring are fed with milk produced by the female´s mammary glands. Most are terrestial; some are aquatic and bats are the only mammal that can fly. Her body is divided in head, tail, skin and trunk.
   • VITAL FUNCTIONS OF MAMMALS
     • NUTRITION: canbe carnivores, herbivores and omnivores. Mammals breathe through  highly developed lungs. REPRODUCTION: reproduce sexually and sexually dimorphic. Although there are oviparous abd ovoviviparous species, most mammals are viviparous.  INTERACTION: have the most well-developed nervous system in the animal kingdom.
   • CLASSIFYING MAMMALS
     • MONOTREMES: are oviparous. MARSUPIALS: complete development of the youngs in the mother´s pouch. PLACENTALS: viviparous. Most have a placenta that nourishes and supplies oxygen to the foetus.

7. DIVERSITY OF VERTEBRATE ANIMALS

   • Are diverse and widespread across the Earth.      HUMAN ARE PRIMATES Are an order of placental mammals that includes monkeys, big apes and humans.
   • HOW DO VERTEBRATES ADAPT TO THEIR ENVIROMENT?
     • CAMELS: store fat in their humps that can provide energy for up to several weeks. FROG: have powerfull back legs are adapted for both swimming and jumping. PREDATOR: usually have sharp teeth, claws, or beaks to ear apart their prey.  REPTILE: her eggs are surrounded by a hard shell that protect the embryo from predators, damage and drying out.
   • ARE VERTEBRATES IN DANGER OF EXTINCTION
     • According to recent studies, approximately a fifth of the world species of vertebrates are facing extinction.
     • ENDEMIC VERTEBRATES OF THE IBERIAN PENINSULA
       • -Aphanius iberus -Iberian frog -Seoane´s viper -Iberian imperial eagle -Cantabrian capercaillie -Iberian lynx