The document provides an overview of the classification and characteristics of vertebrate animals. It discusses the key groups of vertebrates including fish, amphibians, reptiles, birds, and mammals. For each group, it outlines some distinguishing physical attributes and examples of common types within that group.
8. Life Cycle of a Frog Adult Frog Young Frog Fertilized Eggs Tadpoles Adults are typically ready to breed in about one to two years. Frog eggs are laid in water and undergo external fertilization. The eggs hatch into tadpoles a few days to several weeks later. Tadpoles gradually grow limbs, lose their tails and gills, and become meat-eaters as they develop into terrestrial adults.
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Hinweis der Redaktion
Carolus Linnaeus ' (a Swedish botanist , physician , and zoologist ) great work, the Systema Naturæ (1st ed. 1735), ran through twelve editions during his lifetime. In this work, nature was divided into three kingdoms: mineral, vegetable and animal. Linnaeus used five ranks: class, order, genus, species, and variety.
ALL INVERTEBRATES ARE ECTOTHERMIC Fish – bony, cartilagenous, jawless Amphibians (frogs, salamanders, - metamorphosis Reptiles (ectotherms; thick, leathery skin; lungs; most lay eggs) – snakes & lizards, alligators & turtles Mammals – have hair or fur, give birth to live young and nurse young with milk, also have bigger/higher functioning brains
What characteristics do all fish have? Mollusks & arthropods have open circulatory systems The gases fish use to inflate their swim bladders are those of the air around us N2, O2 and CO2, however the proportions are not the same as in the atmosphere and vary between different species of fish. Thus some deep-water marine fish species have up to 84% O2 in their swim bladder while some deep-water freshwater species can have up to 94% N2 in theirs. Lamprey – Jawless Fish, Catfish - bony fish, Sea Ray - Cartilaginous External Fertilization External fertilization in fish: The external fertilization normally occurs in most of fish and in many amphibians. The eggs and sperms are released in the water around the animals and fertilization takes place there. When the fish are about to reproduce, the males and females swim close together. This increases the chance of the sperm cells mixing with the eggs when the both are released in the water. In the amphibians such as the common frog, the male climbs on the females back and stay there until the eggs and sperms have been released. The eggs and sperms now meet in the water and external fertilization takes place. Female animals which have their eggs fertilized externally produce a large number of eggs to ensure their fertilization. The female common frog, for example lays up to two thousand eggs. Hence the external fertilization takes place in this process. Internal Fertilization Internal fertilization of fish: In the process of internal fertilization the eggs remain inside the female’s body and the sperms are placed inside her body by the male. Internal fertilization occurs in insects, reptiles and mammals the males are equipped with a tube which delivers the sperm into the female’s body. In mammals this tube is called a penis. Most birds do not have a tube to deliver the sperm. Instead the sperm passes from the male to female bird when the pairs press the openings of their reproductive systems together. Eggs and sperms must meet in a watery environment for fertilization to take place. For animals live in water such as fish, eggs and sperms can outside the parents bodies. Amphibians are animals that can live on the land but they must return to water to breed as the environment on land is too dry for external fertilization takes place. In internal fertilization the watery environment is provided by the inside of the female reproductive system and this allows the animals to breed without having to return to ponds and rivers. As internal fertilization brings the eggs and sperms close together there is a good chance of fertilization takes place. Animals that rely on internal fertilization for reproduction therefore need to produce fewer eggs.
Whale Shark - Cartilaginous Fish
What characteristics do all amphibians have? New species of salamander found in Columbia 2009 Natterjack toad
Spotted Salamander Fire Bellied Toad Poison Dart Frog
What characteristics do all reptiles have? Iguana Saltmarsh Diamondback terrapin corn snake
Tuatara Coral Snake Nile Crocodile North American Alligator Galapagos Tortoise Sea Turtle
What characteristics do all birds have?
Purple Finch Red-Tailed Hawk Stork Emu
What characteristics do all mammals have?
Marsupials are the group of mammals commonly thought of as pouched mammals (like the wallaby and kangaroo at left). They give live birth, but they do not have long gestation times like placental mammals . Instead, they give birth very early and the young animal, essentially a helpless embryo, climbs from the mother's birth canal to the nipples. There it grabs on with its mouth and continues to develop, often for weeks or months depending on the species. The short gestation time is due to having a yolk-type placenta in the mother marsupial. Placental mammals nourish the developing embryo using the mother's blood supply, allowing longer gestation times. Like other mammals, the marsupials are covered with hair. Mothers nurse their young — a young kangaroo may nurse even when it has grown almost to the mother's size. Placental mammals are a rather diverse group, with nearly 4000 described species, mostly rodents and bats (photos at left). The placental mammals include such diverse forms as whales, elephants, shrews, and armadillos. They are also some of the most familiar organisms to us, including pets such as dogs and cats, as well as many farm and work animals, such as sheep, cattle, and horses. And humans, of course, are also placental mammals. Placental mammals all bear live young, which are nourished before birth in the mother's uterus through a specialized embryonic organ attached to the uterus wall, the placenta .