Geographic Scope

The geographic extent of the project originally (Versions 1.0 and 2.0) was defined as the political area of Texas including the barrier islands and bays. Our data aquisition, georeferencing, and normalizations efforts then focused entirely on records within the political boundary of Texas and those records were only retrievable via queries of verbatim donor fields. However, since fish are unaware of political boundaries and a complete understanding of Texas ecosystems requires inclusion of those parts of Texas basins within other jurisdictions, we aimed add those records.  Although the database always did include some of these records, we've now, with Version 3.0, added numerous new marine and freshwater records from the Gulf of Mexico, inland Mexico, and neighboring US states (Colorado, New Mexico, Oklahoma, Arkansas and Louisiana) from with our shared basins. In Version 3 we make most of these pre-existing records more easily available (see georeferencing) and add our Track 3 dataset, which includes many more records from Texas' neighbors. 

Taxonomic Scope

We limit the taxonomic scope of the project to fishes as defined by those taxa accepted by the American Fisheries Society (Nelson, 2004) and as described here. See our Taxonomy page for a complete and current list of taxa included in the project.

Temporal Scope

We requested records from institutional donors regardless of date and include all records received including those without a date recorded. We do not maintain data on time of day of collection, but in some rare instances such data may be found in verbatim donor data.

Data types

The project is based primarily on data that are "vouchered" by preserved specimens stored in museum collections (see Version 3.0, where we add non-vouchered data to the database). These data are the highest quality occurrence data available since they can be verified at any time by inspection of specimens that will persist indefinitely. Other data sources without vouchers are unverifiable. The ability to verify determinations is critical and our recent work towards correcting errors of determination in the Fishes of Texas Database illustrates the importance of museum specimens. Additionally, data backed by specimens are useful since those specimens can then be used for research in many fields of biological study.

Museum specimens are critically important for researching many aspects of ecology, evolution, biogeography, natural history, and biology in general. Specimens document a snapshot of the environment from which they came since they contain gut contents and parasites and their tissues hold chemical clues about many aspects of their environment. Museum specimens are also potentially very long-lived (many centuries at least) and signals of past environments preserved in them can be studied as long as the specimens persist. Specimens included in this database were collected as far back as the mid-1800s and are almost always in acceptable condition for identification.

The only way to verify anyone's determination of a species' identification is by examination of a specimen, and if one does not exist, questions will always remain. We thus chose to focus primarily on museum specimen-vouchered data as a means to reconstruct the historic record. Our work on this project demonstrates that fish identification errors are common. At the time of this writing, over half of our flagged (as geographic outliers) records had erroneous identifications, but we have found large error rates among species within their known ranges as well and believe all determinations should be seriously questioned.

In many cases specimens are identified incorrectly at the time of deposition in a museum, but in some instances errors are 'created' by the progress of science since species are often divided by taxonomists into two or more new species. The original species names remain in museum databases and labels, but now with incorrect determinations. Museum curated specimens allow researchers to determine the historic distribution of newly split species, provided that determinations can be based on preserved morphology.

With the introduction of our Track 3 dataset (Version 3.0 of the Fishes of Texas Project) we introduced non-specimen vouchered data including, photo vouchered records from citizen science applications, agency databases, researcher databases, and others. These data compliment the specimen record, but usually cannot be verified.