Pheretima

-

PHERETIMA



CLASSIFICATION :

Phylum: Annelida

Class: Oligochaeta

Genus: Pheretima


COMMENTS:

•Commonly known as Earthworm.

•Body is long, narrow and cylindrical measuring upto 150 mm in lengths, brown in colour.

•Anterior end is pointed, while the posterior end is more or less blunt.

•Body is divided by circular furrows into a series by 120 ring-like segments or metameres.

•Each segment (except the first & last) is provided with setae arranged in a ring enclosing the setal sac.

•Mouth is crescentic aperture situated at the anterior end ventral to the prostomium.

•Clitellum, a circulal band of glandular tissue, is present in 14th to 16th segment.

•They are Hermaphrodite. But they do cross fertilization, no case of self fertilization is reported yet.

•Female genital pore lies on the ventral surface in the 14th segment.

•A pair of male genital pore is situated ventrally in the 18th segment.

•Two pairs of genital papillae lie on the ventral surface in the 17th & 19th segments.

•Last segment bears the anus & is called anal segment.







Comments

Post a Comment

Popular posts from this blog

Peripatus

-
Image
PERIPATUS CLASSIFICATION: PHYLUM:  ONYCHOPHORA (contain annelida & arthropoda character). COMMENTS: •It is referred as " living fossil". • Body of the animal is cylindrical & elongated caterpillar like & measuring 4-6 cm in length. •Outer covering of the body is thin,velvety, chitinous showing transverse, wrinkles, numerous small papillae or tubercles. •Anterior end is marked by pre-antennae & ventral mouth & posterior end by anus. •There is a head of three segments. •Post-oral segment of the head bear pair of hooked jaws, a pair of oral papillae, a pair of simple eyes & a pair of segmented antennae. • There are about 15 pairs of walking legs, •There is a tracheal system for respiration with spiracles scattered irregularly over the body surface. •Crural gland is absent & genital pore is posterior. •Connecting link between arthropoda & annelida.
Read more

Bombyx

-
Image
  BOMBYX CLASSIFICATION : PHYLUM ARTHROPODA (Jointed appendage). SUB-PHYLUM UNIRAMIA (single branch appendage). CLASS: INSECTA ( 3 pair of legs ). COMMENTS: • Bombyx is commonly called as silk moth. • Body consists of head, thorax & abdomen. •Head bears a pair of antennae & a pair of compound eyes. •Thorax bears three pairs of legs and two pairs of rings which are covered with scales. • Hindwings are smaller than forewings. • Abdomen consists of 10 segments. •Mouth parts of siphoning type. •Moths are nocturnal,they come in the night during rainy season. •Various stages of life cycle are egg, larva, pupa, adult male & female •Larva feeds mulberry leaves by its mandibles & mouth parts & undergoes moulting as it grows. • Habit & Habitat: They are reared for silk. Adults have short life span & do not feed. • Distribution : cosmopolitan.
Read more

Balanus

-
Image
BALANUS   CLASSIFICATION : PHYLUM:  ARTHROPODA (Jointed appendages) SUB-PHYLUM: CRUSTACEA (Biramous appendages) CLASS: CERRIPEDIA (Adults sessile /parasitic) COMMENTS: •Commonly called as Rock Barnacle. •Stalk is absent to the shell covering animal is directly attached to the substratum or rocks. •Head is short & broad. • Mantle surrounding the body is covered six calcareous plates, consisting of unpaired carina, rostrum & 2 pairs of carino-lateral plates. Edges of the plates overlap & fit together forming a cylinder. • opening of the shell is provided with a movable fourfold lid or operculum, composed of 2 scuta or 2 terga. •In water, the barnacle protrudes through the opening six pairs of delicate, curled, fringed & jointed thoracic legs to collect food. • Life cycle includes nauplius larva. •Distribution: It has cosmopolitan distribution.
Read more