The members of Class Amphibia (Gr., Amphi : dual, bios, life) can live in aquatic as well as terrestrial habitats. Examples: Bufo (Toad) Rana (Frog) Hyla (Tree frog) Salamandra (Salamander) Ichthyophis (Limbless amphibia) Body characteristics: Body is divisible into head and trunk (tail is present in some of them). But neck is absent. Trunk bears … Read more
This class includes fishes with bony endoskeleton. Fins also have bony rays. Habitat: They are found in both marine and fresh water habitats. Examples: Marine Freshwater Aquarium Exocoetus (Flying fish) Labeo (Rohu) Betta (Fighting fish) Hippocampus (Sea horse) Clarias (Magur) Pterophyllum (Angel fish) Body characteristics: Their body is streamlined. Mouth is mostly terminal. They have … Read more
The animals possess jaws and paired lateral appendages. The group is divided into 7 classes. Class Placodermi (extinct) Class Chondrichthyes Class Osteichthyes Class Amphibia Class Reptilia Class Aves Class Mammalia Class : Chondrichthyes Class Chondrichthyes (Chondros – cartilage; ichthys – fish) consists of fishes with cartilagenous endoskeleton. Habitat: All members are marine. These animals are … Read more
In vertebrates, the notochord developed during the embryonic stage is replaced by a cartilaginous or bony vertebral column which forms a protection covering around the dorsal tubular nerve cord. Head is well developed and sense organs are present. The brain is protected by a cranium. They have a ventral muscular heart with one, two, three … Read more
All the animals belonging to Phylum Chordata possess certain fundamental and unique characteristic features. They possess a notochord (or chorda dorsalis) which persists as such throughout their life in some animals, or is replaced by a well developed vertebral column in some others. They have a dorsal, hollow, tubular nerve cord (also known as spinal … Read more
These animals have a rudimentary structure in the collar region called stomochord, which is a structure similar to the notochord and hence the name hemichordates. Habitat: All members of this phylum are marine. Examples: Balanoglossus Saccoglossus Rhabdopleura. Body plan: They have organ-system level of organisation. Symmetry: They are bilaterally symmetrical. Germ layer: They are triploblastic … Read more
The name of the phylum is derived from the presence of an endoskeleton of calcareous ossicles (Greek: echinos– hedgehog, derma– skin). Habitat: All echinoderms are exclusively marine. Body plan: The members have organ-system level of organisation. Examples: Asterias (Star fish) Echinus (Sea urchin) Antedon (Sea lily) Cucumaria (Sea cucumber) Ophiura (Brittle star) Symmetry: The adult … Read more
This phylum forms the second largest animal group in kingdom Animalia. Habitat: They can be terrestrial or aquatic. Examples: Pila (Apple snail) Pinctada (Pearl oyster) Sepia (Cuttlefish) Loligo (Squid) Octopus (Devil fish) Aplysia (Seahare) Dentalium (Tusk shell) Chaetopleura (Chiton) Body plan: They have organ-system level of organization. Symmetry: Molluscans are initially bilaterally symmetrical, but later … Read more
This is the largest phylum in Kingdom Animalia. Majority of the members are insects. Over two-thirds of all named species on earth are arthropods. The name is derived from the presence of jointed appendages (arthros-joint, poda-appendages) on the body. Habitat: They are found in a wide variety of habitats. Examples: Economically important insects: Apis (Honey … Read more
The body surface of Annelids are segmented and distinctly marked out into segments or metameres and, hence, the phylum name Annelida (Latin, annulus : little ring) Habitat: Annelids can be free-living or parasitic. They occupy both aquatic (marine or freshwater) and terrestrial habitats. Examples: Nereis Pheretima (Earthworm) Hirudinaria (Blood sucking leech). Body plan: The members … Read more