PHYLUM ANNELIDA

 

PHYLUM ANNELIDA

GENERAL CHARACTERS :

1.     These are mostly aquatic animals found in freshwater and marine water.
2.    Some annelids are terrestrial and burrowing animals
3.   Body is bilaterally symmetrical elongated worm like.
4.   Body is elongated vermiform, bilaterally symmetrical.
5.  Body is metatmerically segmented
6.  Boy wall consists of longitudinal as well as circular musce. 
7.     Body wall is covered by cuticle.
8.   These are triploblastic and coelomate animals,
9.     Respiration by general body surface. .
10.   Circulatory system is well developed and is of closed type.
11.   Blood is red in colour due to haemoglobin which is dissolved in plasma.
12.   Excretion by nephridia, locomotion by setae, parapodia or suckers.
13. .  The sexes are separate or united.

 (Phylum annelids consists of following four classes i.e. classes — Polycheta, Oligochaeta, Hirudenia and Archiannelida)

EARTHWORM

KINGDOM                                  : ANIMALIA  - Eukaryotic, Multi-cellular, without chloroplast

SUBKINGDOM                          : EUMETAZOA  Diploblastic animal

PHYLUM                                                 : ANNEL1DA  - Body is segmented

CLASS                                         : OLIGOCHAETA Setae are locomotary organs

GENUS                                        : PHERETIMA 

SPECIES                                      : POSTHUMA 

·         CHARACTERS :

1. The body is long, narrow, cylindrical.
2. Anterior end is pointed and posterior end is blunted.
3. Body is divided into 100 to 120 ring like segments. 
4. Each segments is provided setae.  
5. Clitelum is present between 14^th to 16^th segments.
6.  Mouth is present at anterior end.
7.  It is hermaphrodite animal having both male and female sex organ in same individual.
8. Female genital pore lies on ventral surface.
9. A pair of male genital pore is situated ventrally in the 18^th segment.
10.  Last segment bears anus

NEREIS

KINGDOM                                  : ANIMALIA  Eukaryotic, Multi-cellular, without chloroplast

SUBKINGDOM                          : EUMETAZOA

PHYLUM                                     : ANNELIDA

CLASS                                         : POLYCHAETA

·         CHARACTERS:

1.      It lives in burrows in sand or mud so it is commonly known as Rag worm of Clam worm

2.      It is nocturnal and carnivores.

3.      Head bears eyes. Palps, tentacles.

4.      Lateral parapodia are present.

5.       Clitellum is absent.

6.      Parapodia with compound seteae.

7.       It is hermaphrodite animal.

LEECH 

KINGDOM                      : ANIMALIA Eukaryotic, Multi-cellular, without chloroplast

SUBKINGDOM              : EUMETAZOA

PHYLUM                        : ANNELIDA

CLASS                             : HIRUDENIA 

·         CHARACTERS:

1.               It is commonly called as Indian cattle leech found in ponds, marshes and streams.

2.               It is ectoparasitic animal.

3.               Number of body segments. 33 segments are present in a matured leech.

4.               Each segment show superficial divisions called annuli.

5.               Presence of suckers for locomotion and attachment.

6.               Indistinct head with five pairs of eyes situated dorsally in the first five segments.

7.               Animals are bisexual

8.               The male genital pore is situated mid-ventrally in between the 10^th segment.

9.               The female genital pore lies mid-ventrally on the Ith segment.

10.           The anus lies mid-dorsally on the 26th segment.