Question

Axolotl larva of Ambystoma normally fails to metamorphosis, the reason is:
a. Absence of phosphorus in water
b. Lack of iodine in water or diet
c. Lack of Can and Mg ions in water
d. Low concentration of Na and K in water

Answer 1

Hint: The axolotls are a classic example. They're salamanders in the Ambystoma genus. The typical life-cycle contains an aquatic "tadpole" with gills, which metamorphoses to a terrestrial adult salamander. Some Ambystoma species don't undergo the metamorphosis though - they remain in the juvenile stage and become sexually mature.

Complete answer:
Axolotl is, for example, a creature that has both gills (those things waving off of their heads are exposed gills!) and lungs. Both gills and lungs are active in an axolotl and it may choose which it prefers to use.

The type of aquatic salamander, axolotl that looks like a cross between a fish and a lizard. Compared to other reptiles the axolotl is not generally prone to hiding or lying still for long periods, so they are watchable and fascinating to observe. It normally fails to metamorphosis due to a lack of iodine in water. So, option B) is correct.

The Iodine kills the inhibitors by changing the chemical balance for hormone production but also does a lot of damage.

Iodine and other maturity inducers are extremely damaging to them, as their physiology suffers greatly in the hormonal surge and chemical imbalance-not to mention Iodine is extremely damaging to all organic tissue.

Hence, the correct answer is option (B), (lack of iodine ions in water).

Note: Axolotls are native to two lakes in Mexico, Xochimilco, and Chalco. These lakes were both formed by melted glaciers. When Lake Chalco was drained, this killed many axolotls. In recent times, parts of Lake Xochimilco have been filled in, many non-native plants have been introduced, restricting the oxygen levels of the water. Ten species of fish have been introduced, eating both young axolotls and their eggs.