Phylum Echinodermata- Definition, Classification, Characteristics, Examples

Definition Echinoderms are the marine animals that are triploblastic deuterostomes. The larva is bilaterally symmetrical and the adult has modified pentamerous radial symmetry. The integument contains spines and dermal ossicles. They have peculiar locomotory organs, the tube feet and peculiar water vascular system. Some 5,500 living species are known. Brief History It was Jacob Klein … Read more

Protochordata- Characteristics, Classification, Example and More

Protochordates were the first formed chordates that are marine and are triploblastic, bilaterally symmetrical and have organ system level of organization. They also possess a true body cavity called coelom. Characteristics of Protochordata The members of Group-Protochordata (Gr. Protos = first, Chorda = cord) or, Arcania are primitive or lower chordates without a distinct head. … Read more

Phylum Hemichordata-Definition, Characteristics, Classification, Examples

Hemichordates are worm like marine animals having bilateral, coelomate, triploblastic body organization system. Introduction Phylum Hemichordata includes deuterostome animals with enterocoelous coelome. They have pharyngeal gill slits, a buccal diverticulum (doubtful ‘notochord’) and the body is worm-like, divisible into proboscis, collar and trunk. It is a small phylum. Only 100 species are known of it. … Read more

Phylum Chordata- Definition, Classification, Characteristics, Examples

Chordata are highly developed and evolved organism that belongs to animal kingdom. Specific Characteristics of Chordata The members of Phylum-chordate (L. Chorda = string or cord) possess three distinctive characters at some stages in their life history. Those distinctive characteristics are as follows: A longitudinal rod-like notochord. A dorsal tubular nerve cord. A series of … Read more

Phylum Mollusca – Definition, Characteristics, Classification, Examples

Definition The members of Phylum Mollusca are triploblastic, bilaterally symmetrical, eumetazoan, whose body organization is of organ system grade, but are unsegmented. The body is soft, covered with a mantle and usually with a calcareous shell. They are mostly aquatic, but however, some are terrestrial or semiaquatic. There are some 80,000 species of living molluscs … Read more

Phylum Arthropoda- Definition, Classification, Characteristics, Examples

Definition Phylum Arthropoda comprises animals with the bilateral, triploblastic, segmented and coelomate organization. They have an exoskeleton made up of Chitin and jointed appendages used for locomotion, feeding and other purposes. They are known from Palaeozoic era. Some 9,50,000 species or more are known. They are intimately related to man and hence are important. Brief … Read more