Compare any user-selected taxa -- The "What fish is that?" engine also includes the ability to compare images of up to 6 user-selected taxa together on screen, and access their taxon pages.

Step-wise "Find-a-fish" -- The "What fish is that?" engine also uses a the feature "Find a fish", which leads the user to an identification by a stepwise process of elimination. The user completes each step by selecting among categories or entering information on location (by map), shape (two levels), colors (combination of color & pattern; to provide maximum flexibility the default is set at any one pattern and any one color), fish-size, depth and several habitat attributes (inshore/offshore, salinity, habitat type, and water-column position). This feature is sufficiently flexible that any of the six steps can be performed in any order and steps can be retracted. The user can assess search results by clicking on any species name in the resultant list, which connects to its image.

Global endemism -- This zoogeographic attribute focuses on global scale distributions, and provides information on the distribution of the species in large biogeographic areas outside the eastern Pacific. For example: circumtropical species are found in all three major oceans (Pacific, Indian and Atlantic). West Atlantic introducees are aliens to the eastern Pacific that were either intentionally introduced or made their way there through the Panama Canal. New world species occur on both the Atlantic and Pacific coasts of the Americas.Transisthmian species are a tropical subset of the new world species that occur naturally on both the Atlantic and Pacific coasts of the central American isthmus.

Regional endemism -- This zoogeographic attribute concerns the pattern of geographic distribution of each species within the TEP. The categories of this attribute include (i) endemics to the eastern Pacific, which are represented by both (ii) endemics to our region (species that occur only in the region or have the great bulk of their distributions within it), and (iii) temperate eastern Pacific endemics - species whose distributions are primarily to the north and south of our region, in the Californian and Peruvian provinces. (iv) Eastern Pacific non-endemics are species that have populations outside the eastern Pacific (e.g. circumtropical species). Categories relating to the distributions of species within our region include (v) the occurrence of endemic and non-endemic species at offshore islands and/or the continental shore, (vii) whether TEP endemics are endemic to the offshore islands (and which islands) or to the mainland, and (viii) which of the 3 mainland provinces (or combinations thereof) each TEP endemic is known from. A few species are classed as island endemics even though they also are known from the mainland; we have done this because they apparently occur on the mainland only as vagrants.

Climate Zones -- We have divided our region into three climate zones relative to their distance from the equator. The equatorial zone extends between 10N and 10S and includes Costa Rica to northern Peru, and all the offshore islands except the Revillagigedos. The northern tropical zone extends from Nicaragua to the mouth of the Gulf of California at about the tropic of Cancer and includes the Revillagigedos Islands. The northern subtropical zone includes the Cortez province, almost all of which is at a higher latitude than the tropic of Cancer (which passes through the extreme tip of Baja). Our region is bounded to the north by the temperate Californian Province and the northern Gulf of California and to the south by the temperate Peruvian Province. The database includes information on the occurrence of all shorefishes known from both the tropical eastern Pacific and these temperate zones. Antitropical species represent the few temperate species that occur in both temperate zones bordering our region (the Californian and Peruvian provinces) and enter both the northern and southern peripheries of our region.

Data on which the maps are base were largely obtained from the large literature included here in the library. That information was supplemented by our own observations and collections in Mexico, El Salvador, Costa Rica, Panama, Colombia, Ecuador and all 5 oceanic islands/island groups, as well as from (conservatively interpreted) data on site-records listed in FishBase, and data on collection sites for museum specimens listed in the websites of the Scripps Institution of Oceanography and the Los Angeles County Museum.

In the map database each of the 5 oceanic islands and island groups (the Revillagigedos, Clipperton, Cocos, Malpelo and the Galapagos) is considered as a single location, represented by a point. Three inshore islands (the Tres Marias in the southeast mouth of the Gulf of California, Isla Gorgona, off southern Colombia, and Isla de la Plata, off central Ecuador) also are represented by single points in that database. These are the only nearshore islands for which separate faunal data is presented. The coastline of the entire map (about 12,700 km from southern California to nothern Peru) is divided into 360 segments, which average about 35km in length. Because segments are straight lines they necessarily are shorter in ares that have complex shorelines.

The user should be aware of limitations in the data from which the maps of geographic ranges are derived and hence the answers produced by different queries made through the maps and lists engine. The data for each of the 5 oceanic islands (Revillagigedos, Clipperton, Cocos, Malpelo and the Galapagos) are based on the species of shorefishes actually recorded from each, plus any oceanic species whose ranges include that location. The continental range of each species is derived from data on the northern and southern limits of that range; thus they provide only an estimate the potential total fauna at a continental location assuming that all appropriate habitats are present. For example, because the Pacific coast of Honduras consists entirely of part of the upper reaches of the Gulf of Fonseca, habitats are all estuarine and mostly soft bottom. Hence, while Honduras lies within the ranges of about 650 species, only about 1/3 of those enter brackish water and are likely to be found on that country's coastline. Ideally the range maps would be derived from complete faunal censuses made at many intervals along the entire continental coast of our region. However, comprehensive faunal lists exist for very few locations and large sections of the coastline remain unsampled or poorly sampled. As this situation is unlikely to be rectified in the near future we rely on range-limits information. The faunas of the Tres Marias Islands (100km offshore in the southeastern limit of the Gulf of California) and Isla de la Plata (40 km offshore from central Ecuador) are poorly known and both have few confirmed species. Those faunas include many unconfirmed species, species whose ranges include the adjacent coast and that occur at other similar islands. This methods is equivalent to the approach we have adopted with continental range limits.

Because the shorelines of the Sinaloan and Central Mexican Gaps consist entirely of soft-bottom habitats these areas were not included in the continental ranges of species restricted to reef substrata that are known to occur on both sides of either gap.

Engine Features

• Comparing ranges --
  The range-limit distributions of any 1- 5 species/genera/families can be projected onto a regional map simultaneously.

• Assembling faunal lists --
  Total and selective faunal lists for individual locations can be assembled using different categories of certain species attributes. Locations range from individual islands (or discrete island groups, such as the Revillagigedos), to 40km sections of the continental coast, to entire countries, to provinces, and up to the entire region. To increase flexibility we have allowed for lists to be assembled using user-drawn boxes (which follow lines of latitude and longitude) to define the location of interest. Some comparisons of the faunas of two different locations can also be made - all species present in both locations, species shared by both locations, species not shared by both locations. The list making capacity also extends to non-selective lists of genera and families for single and double locations.

  The option is provided to generate lists in alphabetic or systematic order. Lists can be printed or exported.

• Species richness --
  This feature uses range-limit maps to produce color-coded plots of the absolute numbers of species for each of the 5 offshore islands/island groups and the absolute potential numbers of species for each 40km section of the continental coastline. It provides such information for the entire fauna, for the members of each family and for species sharing different biological attributes. Because of limitations in the range-limits data along the continental shore (see above) these patterns should be treated as general patterns; i. e., differences should be examined at the scale of Panama vs Ecuador rather than between adjacent 40km coastal sections, and the number of species in each such coastal section should only be considered as approximate.

  Site lists of family members and of species sharing an attribute can be generated from the richness display map.