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Planetary Biodiversity Inventories: A Response to the Taxonomic Crisis

Lawrence M. Page


Taxonomy, the naming and classification of species, is in crisis. Planetary Biodiversity Inventories (PBIs) offer a way to increase

  • the identification of organisms
  • our knowledge of Earth’s biodiversity
  • student enrollment in taxonomic studies
  • dissemination of information about the planet’s species

May 2006

Taxonomists name, identify, and classify organisms.

As illustrated in the Hall of Biodiversity of the American Museum of Natural History, New York city, the world’s biodiversity is immense. Photo: Dom Dada, Creative Commons.

Taxonomy is the science of identifying and naming organisms and then organizing them into systems of classification. The world faces a taxonomic crisis caused by the combination of the loss of biodiversity1 and severe impediments to taxonomic research.2 In 2003, the U.S. National Science Foundation (NSF) reacted to the taxonomic crisis by launching “Planetary Biodiversity Inventories,” a new initiative intended to remove or reduce impediments to taxonomic research. These impediments are

Taxonomy is in crisis.
  • insufficient taxonomic expertise
  • inadequate funding for research
  • isolation of resources required to complete taxonomic research
PBIs are global inventories of taxonomic groups.

Planetary Biodiversity Inventories

Planetary Biodiversity Inventories (PBIs) are global inventories of large clades (a clade is a related group with a common ancestor) of organisms that are likely to contain many undescribed species or otherwise require major revision to complete their taxonomy. To accomplish the huge task of globally inventorying a large clade, each PBI must engage a multinational team of taxonomic experts and institutions with biological research collections.

Four PBIs have been initiated.

The first competition for PBI funding was held in 2003. Four awards were made by the National Science Foundation (NSF) for the study of

  • plant bugs (Miridae)
  • slime molds (Eumycetozoa)
  • the genus Solanum, a large genus containing nightshades, tomatoes, and related plants
  • catfishes (Siluriformes)
So far the program has proven successful.

A review of progress on one of the PBIs, the All Catfish Species Inventory, suggests that the PBI initiative is successful. Although the All Catfish Species Inventory is only in its third year, it demonstrates that providing funding to taxonomists can significantly accelerate taxonomic research, primarily by reducing the isolation of resources required to complete taxonomic research. In addition, a large number of students are working with scientists on the project and are being trained as the next generation of fish taxonomists. Following is a discussion of the catfish project, which serves to illustrate the goals, organization, and results of a PBI. The project illustrates that PBIs are an effective response to the taxonomic crisis.

All Catfish Species Inventory

The principal goal of the All Catfish Species Inventory (ACSI) is to complete the taxonomy of Siluriformes, a monophyletic order (a group of organisms that includes the ancestral species and all descendent species) of bony fishes. Tasks for completing the taxonomy include

One inventory aims to document all catfish species.
  • describing undescribed taxa (categories of organisms, such as class, genus, species)
  • completing generic and familial revisions on poorly known groups
  • developing identification keys
  • creating regional checklists and field guides
  • making all taxonomically relevant information readily available through publications and websites

Figure 1.

Distribution of scientists and students who have participated in the All Catfish Species Inventory. Some dots represent localities with multiple participants and institutions. Numbers displayed on map show the total number of participants by continent. Graphic courtesy of Mark Sabaj.

Principal investigators on the project are Jonathan W. Armbruster at Auburn University; John P. Friel at Cornell University; John G. Lundberg and Mark H. Sabaj at the Academy of Natural Sciences of Philadelphia; and Carl J. Ferraris, Jr., and Larry M. Page of the University of Florida Museum of Natural History.

Catfishes were chosen as the subject for a PBI because they are


Big Blue, a blue catfish (Ictalurus furcatus) is a popular attraction at the Tennessee Aquarium’s Nickajack Lake exhibit, weighing more than 90 pounds. Photo: Todd Stailey

  • a monophyletic group3-5
  • diverse
  • distributed worldwide6,7
It hopes to identify large numbers of undescribed species.
Research is being conducted worldwide.

Scientists predict that a large number of undescribed species, including those recognized but not scientifically described as well as species yet to be discovered, will be identified. Also important in their selection for a PBI, catfishes were already under study by a large number of taxonomists who provide the nucleus of expertise necessary to identify specimens and revise higher-level taxa. At the start of the project in 2003, 215 taxonomists and students signed on as participants. By early 2006, the number of participants signed onto the project had increased to 360. Most participants are from North America and South America (Figure 1), two regions where systematic ichthyology (the study of fishes) is an active area of scientific research. Other participants are from Asia, Africa, Europe, and Australia. Major efforts are being made to establish collaborations in Asia and Africa, where increased taxonomic research and student training are critically needed.

At the start of the project, 2,855 named species of catfishes were considered to be valid. Although this number of species is small relative to that in some groups of invertebrates (animals without a backbone), catfishes constitute one of the largest orders of vertebrates (animals with a backbone).

  • One in 4 species of all freshwater fishes is a catfish.
  • One in 10 species of all fishes—marine, estuarine, and freshwater—is a catfish.
  • One in 20 species of all species of vertebrates is a catfish.
More than 3,000 to 4,000 species may eventually be identified.

Even with this large number of described species, participants in 2003 estimated that 873 to 1,750 species of catfishes remain to be described. These new species are represented by specimens of recognized but still-unnamed species in institutional collections or are predicted to be discovered through additional fieldwork. The total number of species of catfishes to be recognized by the end of the project is predicted to be between 3,600 and 4,500.

ACSI has a five-year budget of $4.7 million to support taxonomic research on catfishes. Included are funds for participant workshops; fieldwork in poorly sampled regions likely to yield new species (primarily in tropical Africa, Asia, and South America); visits to museums and other institutions with biological collections or taxonomic research programs; assistance with illustrations, data analysis, and other tasks necessary to complete descriptions and revisions; and costs associated with publication.

All Catfish Species Inventory result

Already the number of known species has increased substantially.

Increasing funding for research


Figure 2

Number of new species of catfishes described per year. The All Catfish Species Inventory began in 2003. Graph based on data from Carl Ferraris.

To measure the effectiveness of increasing funding for taxonomic research, the number of new species of catfish described per year was examined for the past 10 years (Figure 2). The number increased substantially in 2004 and 2005 suggesting that, although ACSI is only in its third year, providing even small increases in funding to researchers who usually lack funds can significantly accelerate taxonomic research.

PBIs are training future generations of taxonomists.

Increasing taxonomic expertise To alleviate the second major impediment to taxonomic research, insufficient taxonomic expertise, a large number of students (about 65 graduate students) are working on the project and being trained as the next generation of fish taxonomists. In this effort, PBIs are supplementing another successful NSF program, Partnerships for Enhancing Expertise in Taxonomy (PEET), which prepares future generations of taxonomists by supporting taxonomists who train students to conduct monographic, or revisionary, research.8

Graduate and undergraduate students involved in ACSI receive instruction in taxonomy, phylogenetics, biogeography, and natural history. Postdoctoral associates supported by ACSI participate heavily in research and work with foreign participants. All postdoctoral associates and graduate students participate in fieldwork and become familiar with the natural history and ecology of aquatic organisms. They also participate in museum curation, species descriptions and other systematic research, and manuscript preparation.

Removing the isolation and fragmentation of resources
The third major impediment to taxonomic research, isolation and fragmentation of resources, is a long-standing problem that now can be largely overcome with the nearly universal access that scientists have to the Internet. Two resources have been created to facilitate information flow:

Internet databases provide instant access to new information.
  • The ACSI website describes and illustrates catfish diversity and provides information on projects and participants. Also posted on the website are a bibliography of all papers on the systematics (taxonomy and evolutionary relationships) of catfishes (approximately 2,550 papers) and electronic copies of many old and otherwise difficult-to-obtain articles. These resources provide researchers with instant access to references they might not know about and to papers that otherwise might be unobtainable. Digital images of catfishes are also available. By the end of 2005, images of primary types of catfishes in most major institutional collections (about two-thirds of all primary types) were available. Most of the remaining one-third, scattered among many small institutions, will be photographed by the end of 2006. These images at least enable a researcher to identify the institutions that are critical to visit and at best allows a researcher to complete a study without traveling long distances to examine specimens. Images of live and freshly captured specimens, and of unusual species, also are available to facilitate descriptions, as are online atlases of catfish morphology. The ACSI website is directly responsible for the increase in completed species descriptions and revisions of catfish genera and families.
Taxonomists are also working with government agencies and nonprofits.
  • To facilitate communication among ACSI participants, an electronic mail list server, Siluri-Net, has been established at the Academy of Natural Sciences of Philadelphia. The project newsletter allows ACSI participants and other qualified professionals and students to describe research projects, query participants about the availability of specimens or literature, announce opportunities for scientists to work together on fieldwork and species descriptions, and discuss educational and conservation topics related to catfishes.

  • Many ACSI participants advise conservation NGOs (nongovernmental organizations) and government agencies in the U.S. and abroad. For example, Lundberg and Sabaj have worked with the World Wildlife Fund and Conservation International on projects to delimit freshwater ecoregions and hotspots, and Page has identified threatened species and natural areas for The Nature Conservancy and the International Union for Conservation of Nature and Natural Resources.

PBIs have led to an increase in published studies.

Figure 3

Number of papers on catfish taxonomy published annually in Zootaxa. The All Catfish Species Inventory began in 2003. Compiled by Griffin Sheehy.

In addition to improving access to taxonomic information and communication, ACSI makes it easier for researchers to publish results of their studies. Rapid publication of species descriptions historically has been hampered by the limited availability of publication outlets, the slow rate of processing manuscripts, and high cost. This is true especially for taxonomists working in less-developed countries. In addition to providing funds to cover costs of publication, ACSI provides editorial assistance to participants who choose to publish in Zootaxa, an international electronic journal for taxonomic studies. The number of papers on catfishes published in Zootaxa has increased dramatically, from one in 2001 to 20 in 2005, following the initiation of editorial and financial assistance from ACSI (Figure 3).


A new family of catfishes has been found.

ACSI has two more years to meet its original objectives; however, early signs are that it is a success. Species are being described at a faster rate, and taxonomic information previously unavailable is being published and distributed electronically. Major revisions have appeared;9,10 exciting discoveries have been announced, including the discovery of a new family of catfishes;11 and phylogenetic and diagnostic information for large clades is being published.12,13

Inventorying organisms is crucial as biodiversity continues to decline.

Given the severity of the taxonomic crisis and the success of the catfish PBI, a strong case can be made for additional funding of PBIs by NSF, and PBI-like initiatives should be launched elsewhere in the world. Although it’s too early to comment on the progress of other PBI initiatives that are underway, it is expected that scientific knowledge will be greatly enhanced by the data being generated. A short time remains to document the biological diversity of our planet, and biological surveys and inventories must be a high priority for science. PBIs are a means to address that priority.

The project is cost effective given the knowledge we will gain.

If the original estimates hold and between 873 and 1,750 new species of catfishes are described, the cost will have been between $2,700 and $5,400 per species. Completing the taxonomy, with revisions, identification keys, field guides, and websites with distributional and other information on all 4,500 species of catfish, will have been done for a cost of approximately $1,000 per species. At this rate, and if estimates of 5 million to 10 million species of organisms on Earth are correct, the cost of completing an inventory of the biodiversity of the planet will be only $5 billion to $10 billion. This is a trivial amount considering modern expenditures for the military and health care, and it would produce an unparalleled source of information about the planet Earth and its resources.

Lawrence M. Page, Ph.D., is adjunct curator of fishes at the University of Florida Museum of Natural History, in Gainesville, and principal scientist emeritus in the Center for Biodiversity, Illinois Natural History Survey (INHS). His research interests include the systematics and natural history of freshwater fishes, and the conservation of freshwater ecosystems. He is author of the Peterson Field Guide to Freshwater Fishes of North America and over 120 papers on freshwater organisms.

The All Catfish Species Inventory is funded by U.S. National Science Foundation award DEB-0315963.

Planetary Biodiversity Inventories: A Response to the Taxonomic Crisis


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BioScience Article

“Microbial Diversity Unbound.”
Read Mlot’s December 2004 article, which outlines what DNA-based techniques are revealing about the planet’s hidden biodiversity. Read the citation, or log in to purchase the full article.

All Catfish Species Inventory (ACSI) website

This site’s extensive resources include

  • » information on catfish diversity, including lists of families and genera with numbers of species and images
  • » details about the scope and nature of participants’ research projects, including taxa under study and contact information
  • » bibliography of all papers on the systematics of catfishes (around 2,550 papers)
  • » electronic copies of old and difficult-to-obtain articles
  • » digital images of catfishes, including primary types and live and freshly captured specimens
  • » atlas of catfish morphology
  • » list of repositories for name-bearing types of catfisheslist of acronyms
  • » for institutions with collections of catfishes
  • » instructions for submitting research proposals to ACSI
  • » news and announcements relative to catfish taxonomy
  • » links to other websites with information relative to studies of catfishes
  • » sites supported by scientific societies, anglers, and fish hobbyists

Living on Earth: A Little Known Planet

Read the transcripts or listen to an April 30, 2004, radio program in three segments about planetary biodiversity inventories and discover what some scientists are doing to catalog biodiversity on Earth.

What Is Biodiversity?

This primer on Earth’s biological diversity explains why it’s important to maintain this diversity.

Taxonomy: What’s in a Name?

Get an overview of the science of taxonomy, with links for further exploration.

Integrated Taxonomic Information System (ITIS)

ITIS provides a scientifically credible list of biological names in a unified classification, focusing at minimum on taxa of interest to North America, but with world coverage for many groups.

Tree of Life

The multi-authored project contains information about the phylogenetic relationships and characteristics of organisms and illustrates the diversity and unity of all living organisms.

About catfish

AIBS Online Presentation

View the PowerPoint presentation “Evolution and Diversification in the Tropical Crop, Cassava by Barbara Schaal and Kenneth Olsen, presented at the 2005 evolution symposium “Evolution and the Environment.”

ALL Species Inventory

The ALL Species Foundation is a nonprofit organization dedicated to the complete inventory of all species of life on Earth within the next 25 years—a human generation. You can help by subscribing to their newsletter or donating to their cause.


If you are a biology student, teacher, or scientist, you may want to subscribe to this international journal for taxonomic studies. original lesson

Activities related to the article by L. M. Page were written by The activities on the concept of species were written by the Biological Sciences Curriculum Study. The lesson includes article content and extension questions, as well as two units of activities with masters and worksheets.

Lesson Title: What Is a Species?
Levels: high school (all levels)- undergraduate (year 1)
Summary: This lesson investigates taxonomy and the evolving concept of species. Students can debate whether a “Peakapoo” is a species, consider whether two populations of indigobirds are separate species, consider the conservation benefits of taxonomy … and more!

Download/view lesson.
(To open the lesson’s PDF file, you need Adobe Acrobat Reader free software.)

Useful links for educators

Useful links for student research

In addition to the links in the “learn more” section above:

  1. National Science Board. 1989. Loss of biological diversity: A global crisis requiring international solutions. Report NSB 89-171. Washington, DC: National Science Foundation.
  2. Page, L. M., et al. 2005. LINNE: Legacy Infrastructure Network for Natural Environments. Champaign, IL: Illinois Natural History Survey.
  3. Fink, S. V., and W. L. Fink. 1996. Interrelationships of ostariophysan fishes (Teleostei). Pages 209-247 in M. L. J. Stiassny, L. R. Parenti, and G. D. Johnson (eds). Interrelationships of Fishes. New York: Academic Press.
  4. De Pinna, M. C. C. 1998. Phylogenetic relationships of neotropical Siluriformes (Teleostei: Ostariophysi): Historical overview and synthesis of hypotheses. Pages 279-330 in L. R. Malabarba, R. E. Reis, R. P. Vari, Z. M. S. Lucena, and C. A. S. Lucena (eds). Phylogeny and Classification of Neotropical Fishes. Porto Alegre, Brazil: EDIPUCRS.
  5. Saitoh, K., M. Miya, J. G. Inoue, N. B. Ishiguro, and M. Nishida. 2003. Mitochondrial genomics of ostariophysan fishes: Perspectives on phylogeny and biogeography. Journal of Molecular Evolution 56: 464-472.
  6. Burgess, W. E. 1989. An Atlas of Freshwater and Marine Catfishes. Neptune City, NJ: T.F.H. Publications.
  7. Arratia, G., B. G. Kapoor, M. Chardon, and R. Diogo (eds). 2003. Catfishes. Endfield, NH: Science Publishers, Inc.
  8. Rodman, J. E., and J. H. Cody. 2003. The taxonomic impediment overcome: NSF’s partnerships for enhancing expertise in taxonomy (PEET) as a model. Systematic Biology 52: 428-435.
  9. Vari, R.P., C.J. Ferraris, Jr., and M.C.C. de Pinna. 2005. The Neotropical whale catfishes (Silurifomres: Cetopsidae: Cetopsinae), a reversionary study. Neotropical Ichthyology 3: 127-238.
  10. Sabaj, M. H. 2005. Taxonomic assessment of Leptodoras(Siluriformes: Doradidae) with descriptions of three new species. Neotropical Ichthyology 3: 637-678.
  11. Rodiles-Hernández, R., D. A. Hendrickson, J. G. Lundberg, and J. M. Humphries. 2005. Lacantunia enigmatica (Teleostei: Siluriformes) a new and phylogenetically puzzling freshwater fish from Mesoamerica. Zootaxa 1000: 1-24.
  12. Armbruster, J. W. 2004. Phylogenetic relationships of the suckermouth armoured catfishes (Loricariidae) with emphasis on the Hypostominae and the Ancistrinae. Zoological Journal of the Linnean Society 141: 1-80.
  13. Thomson, A. W., and L. M. Page. In press. Genera of the Asian catfish families Sisoridae and Erethistidae. Zootaxa.


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