Question

Nereis is
A. Carnivorous
B. Herbivorous
C. Sanguivorous
D. Parasitic

Answer 1

Hint: Nereis or Neanthes Fucata is the simplest segmented marine polychaete ringworm. They have around 200 segments or metameres. The initial segment of its body has been fused to form its head consisting of the eyes and peristomium (part of the head in Phylum Annelida). The peristomium in Nereis consists of a pair of tentacles, dorsally two pairs of eyes, and ventrally a pair of short two-jointed palps (front legs in arthropods).

Complete Answer:
1. The Nereis has powerful and sharp jaws in the posterior end of its pharynx.
2. Its Pharynx can be protruded out of mouth by protractor muscles and can be withdrawn by retractor muscles.
3. It captures its prey by everting its pharynx which then brings out the jaws in front for grasping.
4. As we have stated that the Nereis has retractor muscles, it literally gulps the pharynx inside and sends the prey deep down the oesophagus.
5. Sanguivorous animals are blood-sucking animals. They are called hematophagous. As Nereis gulps its prey entirely so they can’t be told Sanguivorous.

Hence, we can say that Nereis is a carnivore.

Note: Nereis has parapodia (lateral protrusions) which helps it to crawl. It is able to swim because of the lateral undulations of its body which are brought by wave-like contractions of its longitudinal muscles. In the oesophagus of Nereis five segments can be seen which are directly communicated with the stomach–intestine. Distinctly, any organ which works as Stomach is absent in Nereis.