Question

Organ of adhesion in Collembolans is known as :

• A. Collophore
• B. Periproct
• C. Paraproct
• D. Hallophore

Hint:

The three unique abdominal structures of Collembola are: the Collophore (adhesion/water uptake on segment 1), the Retinaculum (catch on segment 3), and the Furcula (jumping fork on segment 4).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Collembolans (commonly known as springtails) are small, primitive, wingless hexapods.
They possess several unique abdominal structures that are not found in other insects.

Step 2: Detailed Explanation:
Let us look at the specialized structures of Collembola:
The abdomen of a collembolan consists of six segments.
The first abdominal segment bears a prominent, tube-like structure called the collophore (or ventral tube).
The term "collophore" is derived from Greek words meaning "glue-peg" or "glue-bar," referencing its primary historical function as an organ of adhesion.
The collophore can extrude eversible membranous sacs that secrete a sticky fluid.
This fluid allows the springtail to anchor itself to smooth vertical surfaces and regain its footing after jumping.
In addition to adhesion, the collophore plays an essential role in water absorption, osmoregulation, and respiration.
Let us review the other terms:
- Periproct: The sclerite surrounding the anus in certain invertebrates.
- Paraproct: Sclerites located on either side of the anus in insects.
- Hallophore: This is not a standard anatomical term for Collembola.
Therefore, the adhesive organ in Collembolans is the collophore.

Step 3: Final Answer:
The ventral tube or collophore is the organ of adhesion in springtails.
Thus, the correct choice is (A).