57333
A transparency of 50 percent is enough to make an animal invisible to a predator such as cod at a depth of ; better transparency is required for invisibility in shallower water , where the light is brighter and predators can see better .
 cod
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 cod