Question

Identify the correct pair with respect to endocrine organ and its secretion

• A. Ultimobranchial gland - Calcitonin
• B. Corpuscles of Stannius - Oxytocin
• C. Chromaffin tissue - Prolactin
• D. Pancreas - Adrenaline

Hint:

Endocrine functions in fish to remember:
1. Ultimobranchial $\rightarrow$ Calcitonin (Ca Regulation).
2. Stannius $\rightarrow$ Stanniocalcin (Ca Regulation).
3. Urophysis $\rightarrow$ Urotensins (Osmoregulation).
4. Pituitary $\rightarrow$ GtH, Prolactin, Growth Hormone.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question requires identifying the correctly matched endocrine gland and the hormone it produces in fishes.
Detailed Explanation:

• Ultimobranchial Gland (Option A): In teleost fishes, this gland is responsible for secreting Calcitonin. Calcitonin is a hormone that regulates calcium levels in the blood, primarily by preventing bone resorption and lowering plasma calcium levels. This is the correct pair.

• Corpuscles of Stannius (Option B): These are unique endocrine glands found in bony fishes that secrete Stanniocalcin (formerly called hypocalcin), which is a major hypocalcemic hormone. Oxytocin is a neurohypophysial hormone, not produced here.

• Chromaffin Tissue (Option C): In fishes, chromaffin cells are analogous to the adrenal medulla and secrete catecholamines like Epinephrine (Adrenaline) and Norepinephrine. Prolactin is secreted by the adenohypophysis (pituitary gland).

• Pancreas (Option D): The endocrine portion (Islets of Langerhans) of the fish pancreas secretes Insulin, Glucagon, and Somatostatin. Adrenaline is secreted by chromaffin tissue.

Step 2: Final Answer:
The correct pair is Ultimobranchial gland - Calcitonin.