White-eyed moray eels (Gymnothorax thyrsoideus) are shy, territorial, and require specific care for their well-being. They need a large aquarium with ample hiding places, a secure lid, and a meaty diet, including live and frozen foods. 
Tank Requirements:
Size: At least 92 gallons (350 liters) is recommended for a single eel. 
Hiding Places: Provide plenty of rocks with crevices and caves, as they are shy and need to feel secure. 
Substrate: They prefer a sandy substrate and may burrow. 
Lid: A tight-fitting lid is essential as they can escape. 
Water Quality: Maintain slightly alkaline, brackish water conditions. 
Lighting: Dim lighting is preferred. 
Diet:
Carnivore: They are carnivores and need a diet of meaty foods, including fish, crustaceans, squid, and crabs. 
Feeding Frequency: Feed a large meal every 3-4 days to avoid overfeeding. 
Feeding Tongs: Use tongs to prevent accidental bites as they rely more on smell than sight when feeding. 
Other Considerations:
Territorial: They can become territorial and defend their lair from other fish. 
Not Reef-Safe: They will see reef inhabitants as food. 
Aggressive: They can be aggressive towards other eels or fish if they feel threatened or are not provided with enough hiding places. 
Feeding Issues: They may go on hunger strikes periodically, but this is a normal behavior. 
In summary, white-eyed moray eels require a large, well-decorated aquarium with ample hiding places, a secure lid, and a meaty diet. They are shy and territorial, so it's crucial to ensure they feel safe and secure in their environment.