Question

In toad, Bufo melanostictus, toxins occur in
A. Secretion of parotid glands
B. Skin warts
C. Both A and B
D. Saliva

Answer 1

Hint: Bufo melanostictus secret toxin known as bufotoxin which acts as neurotoxins for predation.

Complete Answer:
- Asian common toad is referred to as Bufo melanostictus toad. The skin gland which is present on the back, neck and shoulder of toads is parotid gland.
- The bufotoxin is a milky alkaloid substance which is a defence mechanism for these small toads.
- The parotid glands position is similar to that of mammalian parotid glands but it differs in function.
- The parotoid gland contains numerous lobules which contain inner layers that are involved in venom formation and release.
- Sometimes the parotid gland appears like wart. These warts are abnormal growth caused by viral infection. The skins and parotoid glands in toads both contain bufotoxins.

Therefore, the correct answer is option C. Both A and B.

Additional information: Heinrich Wieland and his colleagues in 1922, isolated bufotoxin. This toxin physically resembles digitalis. In small dosage it is known to cause heart muscle contraction and is therefore used in the treatment of congestive heart failure. The skin toxin can cause some serious symptoms or even death in animals and also in humans. They can cause severe irritation, increased salivation, vomiting, paralysis, cardiovascular and respiratory symptoms, cyanosis and hallucinations.

Note: Once a Bufo toad has secreted its poison, it can easily burn the eyes and irritate the skin of a human, but it can do far worse. The toxin is absorbed through the mucus membranes of the mouth.