The Tulane Fish Collection is the largest collections of post larval fishes in the world. It presently contains well over 6 million specimens in over 180,000 lots. Genera within the families and species within genera are arranged alphabetically. When the collection was moved to Riverside in 1968, there were attempts to arrange lots within species geographically by drainage basin, and chronologically within drainages, however this arrangement could not be maintained with the large volume of material that has since been added. Efforts are underway to arrange lots by drainage within species.
Type material is housed in a separate room along with a file of all of the original literature.
There is a color-coded, index card file in the Type Room with data on types and original literature arranged both chronologically and phylogenetically. In all, there are 33 holotypes and 38,835 paratypes representing 125 species. An updated type catalog is in was published in 1993 and is available online . The Type Room also houses two specimens of the extinct harelip sucker, Lagochila lacera , on permanent loan from Cornell University, as well as specimens of certain rare or federally endangered species. There are 2010 radiographs representing 21,988 specimens from 284 species and 8 hybrids in 36 families.