BioSolutions: Hydra Eating Daphnia

Hydra Eating Daphnia

Hydra eating behaviors may change in different temperatures. Hydra is a 4-30 mm long multicellular organism, belonging to the Hydridae family. Hydra paralyze their food with nematocysts that extend from their mouth. Hydra are hermaphroditic and have the ability to reproduce both asexually and sexually. They are filter feeders that prey on small arthropods called daphnia, also known as water fleas. Daphnia range between 0.2-5 mm in size and belong to the family Daphniiade. Daphnia reproduce parthenogenetically, resulting in hatchlings that will moult several times before considered adults. Given favorable environmental conditions, females may do this every ten days. Daphnia are a food source for not only hydra but for a variety of various fish and dragon flies. It is well known that metabolism rates are correlated with temperature. Since hydra has been observed to consume daphnia and metabolism is temperature-dependent, I predict that hydra will consume daphnia faster in warm water than in cold water.