Question

Food of Hydra is
(a)Aquatic plants
(b)Aquatic animals
(c)Algae and aquatic animals
(d)Some crustaceans

Answer 1

Hint: Hydra is a very small freshwater organism of the phylum Cnidaria and is found in temperate and tropical regions. They possess special tentacles to catch their prey and engulf them.

Complete answer:
Hydrae is a small, freshwater, or marine organism that feeds on small crustaceans with the help of tentacles. During feeding, they extend their body to maximum length and the tentacles slowly maneuver around the prey and upon contact the nematocysts on the tentacle fire into the prey and coil the prey to move it to the opened mouth aperture. Then the prey gets engulfed.

Additional Information: The predatory hydra eats worms, insect larvae, small crustaceans, larval fish, and other invertebrates with their special method of preying. As we already learned in the answer, they use their tentacles to numb the prey and engulf them completely. After engulfing, the digestion process starts. They have the ability to digest prey that is more than twice their size with the help of their stretchable body wall. After digestion, the remains get discharged through the mouth aperture via contraction.
Let us know the process of ingestion in details-
-First, they extend their body to maximum length and extend their tentacles
-The tentacles expand four to five times their length of the body depending on the distance of the prey.
-Tentacles slowly maneuver around and wait for contact with prey animals.
-When the contact happens, nematocysts on the tentacles of the hydra fire into the prey.
-The prey gets numb and gets coiled by the tentacles.
-The remaining tentacles also joined in no time to subdue the struggling prey.
-The prey surrounded by tentacles is moved into the opened mouth aperture and gets engulfed by it.
Therefore, the correct answer is “Some crustaceans”.

Note: The main food of hydra is Aquatic invertebrates such as Daphnia, which is a planktonic crustacean found in acidic swamps and freshwater habitats, and cyclops, which are freshwater copepods commonly known as water fleas. Some species of hydra maintain a mutual relationship with some unicellular algae as the algae produce photosynthetic products that can be used as food sources for hydra and in return it protects the algae from predators.