Final answer:
The bacteria that might have come with the water on the wet elodea include common aquatic bacteria, such as Actinobacteria, Deinococcus, and Cyanobacteria, all of which naturally occur in aquatic environments.
Step-by-step explanation:
The student is inquiring about the types of bacteria that could have been introduced with water on a sample of aquatic plant elodea. Considering the environment where elodea naturally occurs, it is plausible that various microorganisms, including bacteria, are present in the water. Specifically, referencing the material provided, it is possible that bacteria such as Actinobacteria, Deinococcus, Cyanobacteria, Epsilon Proteobacteria, and Halobacteria could be associated with aquatic environments, though not all would be typically found with wet elodea. Actinobacteria are common decomposers in water, Cyanobacteria are photosynthetic and could accompany plants like elodea, and Deinococcus is known for its radiation resistance. Epsilon Proteobacteria are often found in animal digestive tracts or extreme environments like hydrothermal vents, and Halobacteria specifically thrive in highly saline environments such as salt lakes and would not likely be found with elodea. The precise species present would depend on the particular characteristics of the water source.