Question

What is a cnidoblast cell? Where is it found?

Answer 1

Hint: A cnidocyte (also known as a cnidoblast or nematocysts) is a type of explosive cell that contains a cnidocyst (also known as a cnida (plural cnidae) or nematocyst) that can sting other organisms.

Complete answer:
A cnidoblast is a specialized cell that contains one massive secretory organelle or cnida, which is the phylum Cnidaria. This is a stinging cell found in coelenterates that helps them protect themselves from predators. Cnidoblasts secrete hypnotizing, which paralyzes or even kills the prey.

Cnidoblasts are the phylum Cnidaria's distinguishing feature. These can be found on the body's surface as well as tentacles. These are functional cells found in jellyfish tentacles that can project a thread-like structure as a form of self-defense against other animals or to capture prey.

Each cnidocyte contains a cnida, cnidocyst, nematocyst, ptychocyst, or spirocyst. This organelle is made up of a bulb-shaped capsule that is attached to a coiled hollow tubule structure. A cnidocyte that has not yet matured is known as a cnidoblast or nematoblast. The cell's externally oriented side has a hair-like trigger known as a cnidocil, which is a mechano- and chemo-receptor.

Cnidarians contain over 30 different types of cnidae. They can be classified into the following categories:
1. Penetrant: The penetrant, also known as the stenotele, is the largest and most complex nematocyst. When released, it pierces the prey's skin or chitinous exoskeleton and injects the venomous fluid, hypnotizing, which either paralyzes or kills the victim.
2. Glutinant: a sticky surface used to adhere to prey, also known as ptychocysts and found on burrowing (tube) anemones, which aid in the formation of the tube in which the animal lives.
3. Solvent: A solvent, also known as a desmoneme, is a small, pear-shaped nematocyst. It is made up of a short, thick, spineless, smooth, and elastic thread tube that forms a single loop and is closed at one end. When discharged, it coils tightly around the prey. They are the tiniest of nematocysts. A lasso-like string is fired at the prey and wraps around a cellular projection on the prey known as spirocys.

Note: Cnidocyte subtypes can be found in different parts of the animal. The tentacles of the sea anemone Nematostella vectensis contain the majority of its non-penetrant sticky cnidocytes, the spherocytes, which are thought to aid in prey capture by sticking to the prey. The two penetrant types of cnidocytes found in this species, on the other hand, have a much broader localization, on the outer epithelial layer of the tentacles and body column, as well as on the pharynx epithelium and within mesenteries.