Final answer:
Marine molluscs survive anoxia stress through fermentation of glycogen to succinate for two reasons: continued energy production and elimination of toxic byproducts.
Step-by-step explanation:
Fermentation of glycogen to succinate by tolerant marine molluscs helps them survive anoxia stress for two main reasons:
- Glycogen fermentation allows for the continued production of ATP through glycolysis in the absence of oxygen. This ensures that the mollusc's cells have energy to carry out essential functions even when oxygen is limited.
- By converting glycogen to succinate, the molluscs are able to eliminate lactic acid, which is a toxic byproduct of fermentation. Succinate is less harmful and can be easily eliminated, reducing the potential for cellular damage.