Question

Name the excretory organs of (i) insects and (ii) crustaceans

Answer 1

Hint: Excretory organs of insects functions to excrete the nitrogenous products and excretory organs of crustaceans are located near the base of larger antennas.

Complete answer:
First of all, what are excretory organs? Excretory organs are the organs of the excretory system and the excretory system is that system which removes excess and waste material from the body fluids of organisms which therefore maintains the internal equilibrium and prevents damage to the body too.

In insects, excretory organs are malpighian tubules. These tubules function to excrete the nitrogenous products. These also secrete fluids in the posterior intestine where they are reabsorbed. These tubules are present in variable numbers in different order of the class Insecta like in Odonata there is presence of 50-60 tubules, likewise in Hemiptera there is presence of 1-4 tubules. Tubules are separated into different regions in many species and each region is homogeneous for one cell type.

In crustaceans, excretory organs are green glands. Green glands are located near the base of larger antennas. These are also called as antennal glands. Each gland has three parts which are the end sac, labyrinth and bladder. The labyrinth is involved in reabsorption of glucose, amino acids and ions from tubule fluids.

Thus, the excretory organ of (i) insects - Malpighian tubules and (ii) crustaceans - green gland.

Additional information:
> Malpighian tubule- Potassium is actively secreted into the lumen of tubules, water follows passively due to osmotic forces and it results in the formation of potassium-rich liquid in abundant amounts. This fluid is isotonic to hemolymph but the composition is different.

> Green gland- When the crustacean are in the larva stage, the excretion is performed by two glands, let's take and example, the excretion organs of adult Nebalia and Cypridina are from both glands but the excretory organs of Anotraca is from the green gland and the excretion organs of developed Crustacean are from maxillary gland.

Note: Excretory organs of insects are malpighian tubules and these tubules help to excrete the nitrogenous products and these tubules are present in variable number in different classes while the excretory organ of crustaceans is green gland which is also called as antennal gland and as the name indicates, it is present near the base of antenna.