Ichthyology, commonly defined as "the study of fish" or "that branch of zoology dealing with fish" has a long documented history, dating thousands of years back to the ancient Egyptians, Indians, Chinese, Greeks and Romans (Cuvier 1995).

This long, sustained interest in fish is due to their double role as highly speciose denizens of a fascinating, yet alien world, and as human food. It has generated, over the centuries, highly heterogeneous information—mainly taxonomic, but also referring to zoogeography, behavior, food, predators, environmental tolerances, etc.

Information on fish is widely scattered

This huge amount of information, embodied in a widely scattered literature, has gradually forced ichthyologists to specialize, and thus accounts on fish are now either global, but highly specialized (e.g., Eschmeyer’s Catalog of Fishes of 1998, or Pietsch and Grobecker’s Frogfishes of the World of 1987, to name two outstanding representatives), or local and deep (e.g., Northern European work on cod, or Canadian work on Pacific salmon, both used as paradigmatic fish in many fisheries textbooks). FishBase, as presented in this and, in more detail, in the other chapters of this book, is an attempt to provide key information on fishes of the world, that is both global and deep.

The current version of FishBase contains all fishes known to science and addresses the needs of a vast array of potential clients, ranging from fisheries managers to biology teachers. The features of FishBase that enable it to meet such wide range of needs reside in its architecture, which makes extensive use of modern relational database techniques.

Standardized qualitative information is structured through multiple choice fields Other features of FishBase:

  • all information on a given species in the database is accessible through a unique scientific or common name;

  • the wide use of multiple choice field structures standardized qualitative information;

  • numeric fields record quantitative information that has been previously standardized;

  • numerous cross-relationships between data tables enable previously unknown relationships to be discovered; and

  • the hosting of databases provided by others, with explicit credit, makes FishBase the most comprehensive data source of its kind.

Standardized qualitative information is structured through multiple choice fields

For teachers of aquatic biology, or of specialized ichthyology courses, the uses of FishBase will range from practical solutions to theoretical issues:

  • FishBase is directly useable as data source (i.e., as an electronic encyclopedia on fish), thus complementing classical sources of information on fish (e.g., the Zoological Record, Aquatic Sciences and Fisheries Abstracts), and helping overcome the lack of scientific literature, especially in developing countries;

  • the pictures in FishBase can be used, just as those in taxonomic books, to provide students with a visual impression of the diversity of fish, and/or of specific features of various groups;

  • students will be able to assess the state of knowledge on various groups of fish, and thus obtain some guidance in identifying worthwhile projects; and

  • the species synopses that FishBase can produce by assembling and structuring all entries on one species will help students to obtain material for study (see above) and, perhaps more importantly, to develop a sense of how scattered bits of knowledge can be used to ‘reconstruct’ species, and to show how these fit into their environments (thus encouraging a ‘holistic view’, as now required for most of what we do in the biological sciences).

A series of lectures in ichthyology could be structured around FishBase as illustrated in the examples below.

  • show FishBase pictures through an introductory lecture, to highlight the diversity and colorfulness of fish and similarity of external morphology in related groups (this hopefully would serve to generate interest in the course as a whole, and introduce fish classification);

  • compare the early classification schemes in Cuvier (1995) with a recent one, e.g., that in the Catalog of Fishes (Eschmeyer 1998), ‘hosted’ by FishBase and largely identical with the widely used classification in Nelson (1994);

The species concept and its implications
  • introduce the species concept and its requirements (a formal description with figures, a binomen, a holotype, a type locality, etc.) and implications (synonymies, sister species, etc.), using FishBase as source of examples, and its Glossary for definition of terms;

  • explain the characteristics (meristics, morphometrics) by which fish species are usually defined and hence identified, and compare identification through keys with computer-based identification using the appropriate FishBase routine (see ‘Quick Identification’, this vol.);

  • show how museum and other occurrence records, as included in FishBase, can be used to define distribution ranges and habitats, which can then be used for ecological inferences;

  • show how the latitudinal ranges of fish species can be used to test various hypotheses, e.g., on the relationship between fish biodiversity and shelf area (for marine species) or land area (for freshwater species);

  • define and illustrate various life history strategies, and analyze their frequency distribution throughout the world. Show, e.g., that salmon-type anadromy is extremely rare in subtropical or tropical species (it is well documented only in hilsa, Tenualosa ilisha, ranging from Iraq to Myanmar). Show how students can identify the relative frequencies of different strategies and draw inferences from these;

  • let each student select a species, print out the relevant FishBase synopsis and complement it based on a literature review (and send the result to the FishBase Team); and

  • show or let students derive quantitative relationships between different expressions of fish physiology (e.g., respiration, growth) and temperature (and hence latitude) and identify modifying factors (salinity, gill size, food type, etc.).

A document implementing most of these ideas, called ‘Fish on Line’ is available from the FishBase web site (see Ichthyology course; www.fishbase.org/fish_on_line.htm).

FishBase can be used as a basis for Bachelor's or Master's theses

In the context of higher education, FishBase may also serve as background for Bachelor’s or Master’s theses wherein an area of ichthyology not presently or suitably covered by the tables in this version of FishBase would be ‘broken up’ into choice, numeric and text fields, captured and then analyzed on a comparative basis.

Two theses of this type, one on Mediterranean fish larvae, and one by Achenbach (1990) on fish diseases, have been guided by R. Froese, working with the candidates on behalf of their theses supervisors.


Achenbach, I. 1990. Aufbau und Entwicklung eines rechnergestützten Informationssystems zur Identifikation von Fischkrankheiten. Christian-Albrechts-Universität, Kiel. MS thesis. 58 p.

Cuvier, G. 1995. (French original 1828) Historical portrait of the progress of ichthyology, from its origin to our own time. Translated by A.J. Simpson and edited by T.W. Pietsch. The Johns Hopkins University Press, Baltimore. 366 p.

Eschmeyer, W.N., Editor. 1998. Catalog of fishes. Special Publication, California Academy of Sciences, San Francisco. 3 vols., 2905 p.

Nelson, J.S. 1994. Fishes of the world. 3rd ed. John Wiley and Sons, New York. 600 p.

Pietsch, T.W. and D.B. Grobecker. 1987. Frogfishes of the world. Stanford University Press, Stanford, California. 420 p.

Daniel Pauly