Diversity In Living Organisms (Animalia)
- 1. Done By : P. Sreesh Class : 9 ‘A’ Subject : Biology
- 2. The major group of animals are classified under the Kingdom Animalia, also known as Metazoa. This kingdom does not contain prokaryotes. All the members of this kingdom are multicellular, eukaryotes. They are heterotrophs, they depend on other organisms directly or indirectly for food. Most of the animals ingest food and digest in the internal cavity. Most of the organisms are motile which means they can move independently and spontaneously. There are around 9 to 10 million species of animals, and about 800,000 species are identified. Fossil records of animals were found in the era of the Cambrian explosion, about 540 million years ago. Animals are divided into various sub-groups, biologists have identified about 36 phyla within the animal kingdom including birds, mammals, reptiles, fish, amphibians etc. Animalia
- 5. Porifera • They are primitive organisms, most of them are salt-water sponges. • They do not have organs or nerve cells or muscle cells. • Approximately, 8,000 species exist today. • Example: Sycon, Euspongia, Spongilla.
- 8. Coelentrata (Cnidaria) • This group is composed of jelly-fish and other lower aquatic animals. • Approximately, 15,000 species exist today. • Example: Aurelia, Adamsia.
- 11. Platyhelminthes • This group consists of flat worms. • They inhabit both marine and fresh water habitats and they are mostly endoparasites found in animals. • Example: Taenia (Tapeworm), Fascicola (Liver fluke).
- 14. Nematoda (aschelmeinthes) • It is a group of round worms, most of them are parasites. • This phylum consists of about 80,000 parasitic worms. • Ascaris (Round worm), Wuchereria (Filaria worm), Ancylostoma (hookworn).
- 17. Annelida • They are present in aquatic, terrestrial and are free-living or parasitic in nature. • This phylum comprises of segmented worms. • Example: Nereis, Pheretima (earthworm), Hirudinaria (blood sucking leech).
- 20. Arthropoda • This is the largest phylum which consists of insects. • There are over 1 million species of insects existing today. • Example: Locusts, Butterfly, Scorpion, Prawn, Apis (honey bee), Bombyx (Silkworm), Laccifer (lac insect), Anopheles, Culex and Aedes (mosquiotes), Limulus (king crab).
- 23. Mollusca • It is the second largest phylum. • They are terrestrial and aquatic. • Example: Pila (Apple snail), Octopus (devil fish), Pinctada (pearl oyster), Aplysia (sea-hare), Sepia (cuttle-fish), Dentalium (Tusk Shell), Chaetopleura (Chiton).
- 26. Echinodermata • This consists of sea stars and sea urchins. • There are about 6,000 species. • Example: Ascarias (star fish), Echinus (sea urchin), Antedon (Sea lily), Cucumaria (sea cucumber), Ophiura (brittle star).
- 29. Chordata • Animals of this phylum have a characteristic feature of presence of notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. • Within this phylum advanced group called vertebrates which include fish, amphibians, reptiles, birds and mammals. • Example:Balanoglossus, Ascidia. All fishes, amphibians, reptiles, birds and mammals.
- 31. Vertebrata • Vertebrates comprise all species of animals within the subphylum Vertebrata. • Vertebrates represent the overwhelming majority of the Chordata, with currently about 66,000 species described. • All Chordates posses the following features : i. have a notochord ii. have a dorsal nerve cord iii. are triploblastic iv. have paired gill pouches v. are coelomate Vertebrates are grouped into five classes.
- 32. 1. Pisces • Pisces In older classifications, a superclass containing the four classes of fish: the two extant classes Chondrichthyes (cartilaginous fish, e.g. sharks) and Osteichthyes (bony fish), the extinct class Placodermi, and also the most primitive of the vertebrates of the class Cephalaspidomorphi.
- 34. 2.Amphibia • All amphibians: Are vertebrates (which means they have a backbone or spine) Are ectothermic. Also known as “cold-blooded,” ectothermic animals cannot regulate their own body heat, so they depend on warmth from sunlight to become warm and active.
- 36. 3.Reptilia • Reptiles are the creeping and burrowing cold blooded vertebrates bearing epidermal scales. • They are ectothermic (cold-blooded) and are found mostly in the warmer parts of the world. They are few in colder parts. • They are mostly terrestrial animals. • There are about 6,000 living species of reptiles in the world. • Skin is dry, rough and without glands, bearing epidermal scales or scutes.
- 38. 4.Aves • Birds (Aves) are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. They are warm – blooded.
- 40. 5. Mammalia • Are vertebrates (which means they have a backbone or spine). • Are endothermic. Also known as “warm-blooded,” endothermic animals regulate their own body temperate which allows them to live in almost every climate on Earth. • Have hair on their bodies. • Produce milk to feed their babies.