External morphology
The Tulane Fish Collection is rich in material of Carpiodes (12,448 specimens of C. carpio, 577 specimens of C. cyprinus, 9,453 specimens of C. velifer, and 123 specimens of Carpiodes [species undetermined]) and Ictiobus (741 specimens of I. bubalus, 222 specimens of I. cyprinellus, 53 specimens of I. niger, and 531 specimens of Ictiobus [species undetermined]). Most of the material is from Gulf Coastal drainages and major tributaries of the lower Mississippi River. The Tulane Fish Collection also has a fair amount of skeletal material available for study (especially for species of Ictiobus), and we are in the process of preparing additional skeletons from newly collected specimens. Tulane holdings are weakest for northern tributaries of the Mississippi River, Hudson Bay drainage and the Laurentian Great Lakes, the north Atlantic Coast, and Mexico. However, we have taken inventory of ictiobine material in other fish collections, and find that these collections have ample material available for study from areas where the Tulane holdings are limited. Fish collections at the University of Michigan Museum of Zoology, Field Museum of Natural History, National Museum of Natural History, Academy of Natural Sciences, and the Illinois Natural History Survey are rich in material from the upper Midwest, Great Lakes, Ohio River, and northern Atlantic Coast. Fish collections at the Texas Memorial Museum and the Museum of Southwestern Biology in Albuquerque, NM are rich in material from the American Southwest. The Field Museum and the Museum of Zoology, and to a lesser extent the Texas Memorial Museum, have good representation of the Mexican forms. However, more Mexican material is needed, especially adults, from lowland portions of rivers draining into the Gulf of Mexico (Robert R. Miller, pers. comm.).
For the past 10 years, we have been traveling to rivers along the eastern Gulf, lower Atlantic Coast, and upper Midwest, accumulating material from these sparsely represented areas, and (in the last two years) collecting tissues for genetic analysis (allozymes, isozymes, and mtDNA sequencing). We have accomplished this by teaming with fellow ichthyologists and state fishery biologists (see Field Work), and assisting in large river sampling trips arranged for game fish monitoring or conservation purposes. These collecting trips typically involve a few to many boats and electrofishing equipment. Electrofishing is an effective means of collecting large river fishes. By assisting in these efforts, we have been able to collect large numbers of specimens of most of the ictiobine species from a number of parts of their respective ranges. We will continue to participate in these sampling efforts to obtain the specimens and tissues we need to complete this study.
We soon hope to network with ichthyologists in Texas and New Mexico (Dean Hendrickson of the Texas Memorial Museum, Kirk Winemiller of Texas A&M University, Gary Garrett of Texas Parks and Wildlife, and Steve Plantania of the Museum of Southwestern Biology) for assistance collecting specimens and tissues of all forms occurring in the southwestern U.S. We are presently corresponding with ichthyologists in northern Mexico (Salvador Contreras and Lourdes Lozano, Universidad Autonoma de Nuevo Leon) to arrange for the collection of specimens and tissues from that region. With the help of Dr. John Lyons of the Wisconsin Department of Natural Resources, we are establishing collaborations with ichthyologists in Mexico City (Dr. Eduardo Diaz Pardo, IPN and Dr. Hector Espinosa, UNAM) that will enable us to collect material from the southernmost area of the distribution of the Ictiobinae.
We will use preserved material to examine patterns of geographic variation in gross morphology and to establish reliable characters for the identification of species at different life stages. Our approach to morphological aspects of the revision will be to first work through material in the Tulane Fish Collection species by species, and then travel to other museums to study types and work up material the Tulane collection is lacking. Ictiobines are large fish that are not easily shipped. Traveling to other collections will give us the opportunity to study the specimens on site, and may afford us additional opportunities to collect fresh tissues for molecular sequencing and allozyme/isozyme work.
Suttkus has been studying skeletons and gathering data on a standard assortment of meristic and morphometric characters from Tulane specimens for a number of years. These data will form the basis of the taxonomic descriptions. Bart has been analyzing morphometric data gathered from museum specimens to get a feel for shape variation within the species complexes. He has also been collecting and photographing specimens in the field to obtain tissues, additional specimens for study, and to get a feel for natural color variation. The PI's expect to complete their initial work-up of Tulane material by the end of 1999. Starting in January of year 2000, the PI's will travel to museums to study types and other specimens (see Types and Their Location). Having already worked through material at Tulane, we should have a good sense of the characters useful for distinguishing species. This will make our work at other institutions more efficient, it will aid us in working with types (some of which are old and in poor condition), and it will reduce to likelihood that we will have to return to the museums to re-examine material.
