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Batrachospermum :Origin ,strucutre ,Thallus organisation and reproduction

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                                              Batrachospermum Occurrence:-   (1) Batrachospermum is fresh water alga.    (2) It is found in clear, cool, and running streams.   (3) Deepwater plants are dark violet or reddish in color. But the shallow-water species are olive green.   (4) The intensity of light changes the color of pigments.   (5) The thallus is attached to the substratum. Vegetative structure  (1) The thallus of an adult plant is soft, thick, filamentous.  (2) It is freely branched and gelatinous.   (3) The central axis is made up of a single row of large cells. Whorls of branches of limited growth        are developed on this axis.  (4) These branches are filamentous and dichotomously arranged.  (5) The main axis is corticated. It consists of a row of elongated cylindrical cells....
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Biological Classification of Phylum Porifera and Ctenophora

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                              Kingdom Animalia



Phylum Porifera :-


The name of this phylum is due to presence of pores on the surface of this members.Ostia and osculum .
Porifera
(a) Sycon                                (b) Euspongia


Characters of this phyla :-
(1)          Cellular level of organization(new body is formed by the help of cell )
(2)          Acoelomate (coelomic cavity absent )
(3)          Water Canal  system is present.
(4)          They are mainly marine but some members lives in fresh water (Euspongia).
(5)          Diploblastic (Presence of only two germ layers).
(6)          Their body is supported by skeleton called spicules which are made up of Calcium carbonate, Silica or Spongyn fibre.
(7)          Digestion is intacellular.
(8)          Asexual reproduction is by internal and external budding or gemmule formation .
(9)          Development is indirect and  by the amphiblastula larva.
(10)         Excretion and respiration is by body surface.
Phylum is divided into 3 class
(1)  Calcarea:-
                 Exclusively marine animals found in this class
              e.g.:-  Sycon .leucosolenia
(2)  Hexactinellida:-
                 All are marine found in deep sea.
       They are mostly solitary..
e.g.- Myalonema, Euplectella, etc.
(3)  Demospongiae:-
They are mostly marine and few are fresh water forms.
They are solitary or colonial.
e.g:- Euspongia, Songilla etc.


Phylum ctenophora  :-


It is the smallest phyla in animal kingdom .The member of this phyla is called Comb jelles and comb plates .It shows biolumisense  property ( means property of glow).All members is free swimming planktonic marine animal .



Pleurobrachia
Pleurobrachia


About 50 species found of this phyla.

 Cnidocytes absent but tentacles carry Tasso cells (colloblasts).

 Eight meridional rows of ciliary plates are present which help in locomotion.

 Carnivorous animals having gastro-vas­cular cavity with mouth and anal pore.
The description of ctenophore is given by marten and Hatschek put it into another phyla.
In beroe the tetacles are absent.
Examples or members of ctenophore
:- Pleurobrachia,velamon,Ctenoplana etc.







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