Answer:
Do a literature search to find natural history information on closely related species.
Step-by-step explanation:
In the context, few graduate students monitored the benthic organisms from the fresh lake water samples and identified the invertebrate species that are present.
They also discover a crustacean which appears to be the new species for which they decided to do a study on its natural history. The first thing that the graduate student should do is to do a literature search for finding a natural history on the information that are closely related species.