Question

Which of the following is marine leech?
a) Haemadipsa
b) Bonellia
c) Hirudinaria
d) None of the above

Answer 1

Leeches are the members of phylum Annelida of kingdom Animalia. Their scientific name is Hirudinea. They are parasitic worms that sucks blood out of the host body. They are similar to oligochaetes such as Earthworms.

Complete answer:
These leeches are capable of living in both water and land. They have a segmented, slimy body. They have sharp sphincters on their frontal end. They suck blood through these sphincters until they become heavy enough to move from one place to another. Thus, they live only on the blood of their host's body.
The Haemadipsa leech is commonly known as jawed land leeches. They are found in the adjoining regions of Indian and Pacific Ocean. Thus, they are not marine leeches. Therefore, it is an incorrect option.
Bonellia leech is another variety of leeches. It is also known as green spoon worms. They live in marine habitats commonly found in the Indian, Pacific and Atlantic oceans. Their skin is biocidal and is capable of affecting the host body chemically or biologically. Thus, they are very dangerous predators. Therefore, it is the correct option.
Hirudinaria is another leech. It is most commonly seen on Indian lands. They are inhabitants of fresh water such as lakes, rivers, ponds, etc. They have a wide range of hosts including humans. They are commonly known as cattle leech. As it belongs to fresh water thus is an incorrect option.

So the correct answer is option b)

Note:
Despite being dangerous, these leeches were used in medical science in surgeries. They are believed to have such only the 'bad' blood from the body. This practice was earliest used in Ayurvedic treatments in India.