Traditional Identification Methods
The traditional procedure for identifying organisms involves comparing the physical characteristics of a collected specimen with the characteristics for a known species. There are numerous taxonomic books that describe the physical appearance, both externally and internally, of millions of species, as well as what is known about their habitats and general biology. Census researchers study collected specimens, often through microscopes, to distinguish features such as the number of tentacles on a jellyfish or the length of spines on a deep-sea anglerfish, and match what they find with existing species descriptions. The Census of Marine Life has collected a large number of species previously unknown to science and there is a backlog of species to be described by taxonomists. Another relevant effort by the Census of Marine Life is the World Registry of Marine Species (WoRMS), which is attempting to provide an authoritative and comprehensive list of names of marine organisms, including information on valid species names, synonyms and vernacular names. While highest priority goes to valid names, other names in use are included so that this register can serve as a guide to interpret taxonomic literature.
The image above contains species of worms. The diversity of marine species demonstrates the difficulty of taxonomic identification. (Natural Geography in Shore Areas - NaGISA. Tetsuya Kato)
Taxonomists sorting through samples of newly collected organisms in Libong Island, Thailand. (Natural Geography in Shore Areas - NaGISA. Somchai Bussarawit)
Identification of fish in the laboratory of a research vessel during a cruise. (Mid-Atlantic Ridge Ecosystems - MAR-ECO. John Galbraith)
In-depth identification often requires the study of microscopic details by highly trained taxonomists. (Census of the Diversity of Abyssal Marine Life - CeDAMar)