zoologylover

Birds have high metabolic rates and require a large amount of energy for flight. Due to this energy consumption, they have a voracious appetite. Small birds have high metabolic rates and eat more food relatively their body weight than the large birds. For example, hummingbirds feed almost constantly during the day. But still cannot maintain high metabolic rate at night, hence, become torpid. Classification of birds based on food All the birds are grouped on the basis of their feeding habits. Birds are classified into two groups; Euryphagous These birds are omnivorous and feed almost everything which is available in season. But they have to compete with other omnivores having the same spectrum of food. Stenophagous These birds are specialist and feed very selectively. Their food basically has few species, and if some hazard like disease occurs in their prey, it proves very dangerous for them and most probably they become extinct. Bill and tongue modification Different...

This phylum is also known as Coelenterata due to the presence of cavity known as coelenteron. This phylum takes its name due to the presence of cnidocytes, which contain organelles (cnidae) characteristics of the phylum. This phylum has the known species of almost 9000 and in some books, 11000 species are also mentioned.  It includes plant like hydroid, jellyfish, sea anemone and coral etc. They may be in the form of a sessile polyp or freely floating medusa. Cnidaria Evolution of the nervous system was first time observed in cnidarians Characteristics of  phylum Cnidaria I.    Stinging cells called nematocysts housed by cnidocytes are found in the phylum. II.    Most are marine but some are also present in fresh water. III.    Possess radial or biradial symmetry (modification of radial symmetry). IV.    Diploblastic and show tissue level organization. V.    Mesoglea which is non-c...