Comments of Hirudinaria
Distribution:
Hirudinaria has cosmopolitan or world wide distribution specially found in India and Myanmar.
Habit and Habitat:
Hirudinaria is found in freshwater ponds, lakes, slow running streams and swamps. It is sanguivorous in Habit.
General characters:
1. Hirudinaria granulosa is commonly known as Indian cattle leech.
2. Body is elongated, dorso- ventrally flattened, measuring 30-35 cm in length with dorsal surface green and ventral surface organ yellow in color.
3. Body is divided metamerically into 33 somites or segments. Each segment is further divided into rings or annuli.
4. Anterior and posterior suckers are well-developed.
5. Dorsal five segments bear five pairs of eyes.
6. Alimentary canal is a straight tube.
7. Sexual reproduction is common.
Economic Importance:
Hirudinaria medicinalis has been used to reduce blood pressure in humans since ancient times.
Diagram of Hirudinaria
hirdinaria granulos
Comments of Nereis
Distribution:
Nereis is cosmopolitan in distribution and found in coastal water of pacific and North Atlantic oceans, Europe and U.S.A.
Habit and habitat:
Nereis is found in burrows in sand or mud of the sea shore at tide level.
General characters:
1. Nereis is commonly known as ragworm or clam worm.
2. The body is long, slender and dorso-ventrally flattened reaching a length of 5-30cm.
3. The body consists of a distinct head followed by a number of similar Segments.
4. Peristomium bears four slender cylindrical tentacles on each side.
5. Sexes separate, gonads develop temporarily during reproductive season.
6. The sexual phase of Nereis is known as Heteronereis.
7. The last or anal segment is without parapodia but bears a pair of appendages known as anal cirri and a terminal anus.
Economic Importance:
Nereis Vexillosa is an important food item for foraging birds in the intertidal zone.
Diagram of Nereis
