Jain Journal 2013 07

Author(s): Satyaranjan Banerjee
Publisher: Jain Bhawan Publication

Page 19

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JAIN JOURNAL: VOL-XLVIII, NO. 1-IV JULY 2013-JUNE 2014
The current biology, however, classifies the living beings on not only morphological structure, shape etc. but also on the genetic relationship. According to modern Zoological classification there are two broad categories non-chordata or Invertebrates: and Chordates. All the vertebrates including human beings belong to phylum Chordata. There are ten invertebrates or non-chordate phyla as described in the Table 3 and five classes under Phylum Chordata (Table 4). The organisms which possess dorsally placed notochord, pharyngeal gill slits and single dorsal hollow nerve cord are included in Phylum Chordata. Whereas the invertebrates don't have any notochord, and there nerve cord is solid, double and ventrally placed.
Table 3. Classification of Invertebrates according to modern
Zoology
Group
Phylum
Class
Characters
Examples
Sub-Kingdom Protozoa
Microscopic unicellular animals free living or parasitic
Monocystis sp. Amoeba sp. Parameciun sp
1. Sarcomasti
gophora 2. Labyrintho
morpha 3.Apicomplexa 4.Microspora 5. Ascestophora 6.Myxozoa 7.Ciliophora
Porifera
Euspongia sp. Euplectella sp. Sycon sp.
1.Calcarea Diploblastic, 2.Hexactinellida acoelomate and 3.Demospongiae whole body is
perforated by pores or ostia,presence of special type of cell called choanocyte
Cnidaria
1.Hydrozoa
Diploblastic,
Aurelia sp.
2.Scyphozoa 3.Anthozoa
acoelomate Presence of nematocyst, gastrovascular cavity
Hydra sp Metridium sp.
Ctenophora
1. Tentaculata 2. Nuda
Beroe sp. Coeloplana sp.
Transparent gelatinous body, lacking nematocyst, possess ciliary plates in eight rows