Numerical strength of
chorodata:-
The number of chorodata in
comparision to other phylum of invertebrate is not so large.There are about
49000 species of chorodata recorded till now which is only half of the
species of Molluscs and less than one tenth of the Arthropods.The two subphyla Cephalochorodata and Urochorodata numbers nearly 2500 species and the sub phylum
vertebrata includes 46500 species.Among the vertebrata , fishes ate the most
numerous with approximately 25,000 species.The number of Amphibians species is
2500, reptiles 6000, birds 9000 and mammals 4500 species .
Size of the chorodates:-
Though the number of
chorodates is not so
 |
| blue whale |
high but they make disproportionate
contribution to the
biomass of the earth.
Nearly all of them are medium to large
in size. Some of
these vertebrates are
so large that they are the largest animals
on the earth.
The largest animal on the
 |
| blue whale at sea shore |
earth is Blue whale is 35 meters long
and 120
tons in weight.Its scientific
name is Balaenoptera musculus. Even the second largest animal on the earth is a vertebrate. It is called the whale shark commonly and scientifically named as
Rhineodon typus.It is 15 meter in length
and the smallest fish isPhilippine goby
 |
| whale shark |
scientifically known
as Pandaka is only
10mm in length.
 |
| Pandaka pygmea |
 |
| Pandaka |
