Research Article |
Corresponding author: Neil Cumberlidge ( ncumberl@nmu.edu ) Academic editor: Ingo S. Wehrtmann
© 2014 Neil Cumberlidge, Fernando Alvarez, Jose Luis Villalobos.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Cumberlidge N, Alvarez F, Villalobos J-L (2014) Results of the global conservation assessment of the freshwater crabs (Brachyura, Pseudothelphusidae and Trichodactylidae): The Neotropical region, with an update on diversity. In: Wehrtmann IS, Bauer RT (Eds) Proceedings of the Summer Meeting of the Crustacean Society and the Latin American Association of Carcinology, Costa Rica, July 2013. ZooKeys 457: 133-157. https://doi.org/10.3897/zookeys.457.6598
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The freshwater crabs of the Neotropics comprise 311 species in two families (Pseudothelphusidae and Trichodactylidae) and one or both of these families are found in all of the countries in the Neotropical region (except for Chile and some of the Caribbean islands). Colombia (102 species, 81% endemic) and Mexico (67 species, 95% endemic) are the biodiversity hotspots of freshwater crab species richness and country-level endemism for this region. The results of the IUCN Red List conservation assessments show that 34% of pseudothelphusids and 10% of trichodactylids have an elevated risk of extinction, 29% of pseudothelphusids and 75% of trichodactylids are not at-risk (Least Concern), and although none are actually extinct, 56% of pseudothelphusids and 17% of trichodactylids are too poorly known to assess (Data Deficient). Colombia (14 species), Venezuela (7 species), Mexico (6 species), and Ecuador (5 species) are the countries with the highest number of threatened species of Neotropical freshwater crabs. The majority of threatened species are restricted-range semiterrestrial endemics living in habitats subjected to deforestation, alteration of drainage patterns, and pollution. This underlines the need to prioritize and develop conservation measures before species decline to levels from which they cannot recover. These results represent a baseline that can be used to design strategies to save threatened Neotropical species of freshwater crabs.
Pseudothelphusidae , Trichodactylidae , Neotropical region, conservation, distribution, endemism
The Neotropical region occupies the entire South American continent, plus Mexico and Central America, the islands of the Caribbean, and southern Florida. The Nearctic/Neotropical boundary runs through Mexico and passes through the southern parts of Baja California and Sonora, crosses the Meseta Central, and continues to southern Veracruz. The majority of the Neotropical region has a tropical climate with warm water freshwater ecosystems, but the southern part of this region from 10° to 25°S (southern Brazil, Uruguay, Paraguay, Argentina, and Chile) has a subtropical climate with cooler freshwater habitats. Freshwater crabs are found throughout the freshwater ecosystems of the Neotropical region but are notably absent from Baja California and the Yucatan Peninsula (Mexico), southern Florida (USA), some of the Caribbean islands, southern Argentina, and all of Chile.
Our knowledge of the impressive freshwater crab fauna in this region has been very slow to develop since the first species of trichodactylid and pseudothelphusid freshwater crabs were described in 1783 and 1840, respectively. Only one species (a trichodactylid) was described in the 18th C (
Species of Neotropical freshwater crabs described since
Family | Subfamily/Tribe | Species | Country |
---|---|---|---|
Pseudothelphusidae | Kingsleyini | Microthelphusa lipkei Magalhães, 2010 | Brazil |
Pseudothelphusidae | Kingsleyini | Brasiliothelphusa dardanelosensis Magalhães & Türkay, 2010 | Brazil |
Pseudothelphusidae | Strengerianini | Phallangothelphusa juansei Campos, 2010 | Colombia |
Pseudothelphusidae | Strengerianini | Phallangothelphusa martensis Cardona & Campos, 2012 | Colombia |
Pseudothelphusidae | Hypolobocerini | Neostrengeria alexae Campos, 2010 | Colombia |
Pseudothelphusidae | Hypolobocerini | Neostrengeria natashae Campos, 2011 | Colombia |
Pseudothelphusidae | Potamocarcinini | Potamocarcinus darienensis Magalhães, Campos & Türkay, 2013 | Panama |
Pseudothelphusidae | Hypolobocerini | Allacanthos yawi Magalhães, Lara & Wehrtmann, 2010 | Costa Rica |
Pseudothelphusidae | Potamocarcinini | Odontothelphusa apicpac Villalobos, García & Velázquez, 2010 | Mexico |
Pseudothelphusidae | Potamocarcinini | Sylvathelphusa kalebi Villalobos & Alvarez, 2013 | Mexico |
Pseudothelphusidae | Potamocarcinini | Sylvathelphusa cavernicola Villalobos & Alvarez, 2013 | Mexico |
Pseudothelphusidae | Potamocarcinini | Tzotzithelphusa villarosalensis Villalobos & Alvarez, 2013 | Mexico |
Pseudothelphusidae | Pseudothelphusini | Pseudothelphusa zongolicae Alvarez, Villalobos & Moreno, 2012 | Mexico |
Research on the Neotropical freshwater crabs has also focused on their phylogeny (
The objectives of the present study are to describe and update our knowledge of Neotropical freshwater crab diversity of both the Pseudothelphusidae and Trichodactylidae and to describe the patterns of distribution and endemism within these families. We also identify here not only those species that are most vulnerable to extinction, but also those species that are poorly known and obvious candidates for future research attention.
Comprehensive distributional data for the Neotropical freshwater crabs were compiled from literature and museum records, particularly the major monographs on the Pseudothelphusidae by
The Neotropical region has its own distinctly recognizable freshwater crab fauna, with no species occurring in other parts of the world. The Neotropical freshwater crab fauna is not uniformly distributed and species and genus composition changes from country to country (Table
Distribution of Pseudothelphusidae (P) and Trichodactylidae (T) in each country in the Neotropical region that has populations of freshwater crabs. First number indicates the number of genera, species, and localities of Pseudothelphusidae, the second number indicates the same data for the Trichodactylidae.
No. GENERA (P, T) | No. SPECIES (P, T) | |
---|---|---|
South America | ||
Argentina | 0, 5 | 0, 9 |
Bolivia | 0, 6 | 0, 8 |
Brazil | 6, 10 | 19, 31 |
Colombia | 13, 8 | 88, 14 |
Ecuador | 3, 4 | 21, 5 |
French Guiana | 2, 4 | 3, 4 |
Guyana | 3, 3 | 8, 3 |
Paraguay | 0, 6 | 0, 7 |
Peru | 2, 9 | 8, 14 |
Suriname | 3, 3 | 5, 3 |
Uruguay | 0, 1 | 0, 2 |
Venezuela | 11, 7 | 35, 9 |
Mexico and Central America | ||
Mexico | 15, 2 | 63, 4 |
Belize | 4, 0 | 4, 0 |
Costa Rica | 4, 0 | 14, 0 |
El Salvador | 4, 0 | 6, 0 |
Guatemala | 6, 0 | 12, 0 |
Honduras | 2, 0 | 3, 0 |
Nicaragua | 3, 3 | 5, 3 |
Panama | 4, 1 | 14, 1 |
Caribbean | ||
Cuba | 2, 0 | 9, 0 |
Dominica | 1, 0 | 1, 0 |
Dominican Republic | 1, 0 | 2, 0 |
Guadeloupe | 1, 0 | 1, 0 |
Haiti | 1, 0 | 1, 0 |
Martinique | 1, 0 | 1, 0 |
Puerto Rico | 1, 0 | 1, 0 |
Saint Vincent & the Grenadines | 1, 0 | 1, 0 |
St Croix US Virgin Islands | 1, 0 | 1, 0 |
Trinidad & Tobago | 2, 1 | 2, 1 |
The Neotropical freshwater crab fauna, which represent 20–22% of the world’s freshwater crab species diversity (
This family comprises two subfamilies, Epilobocerinae and Pseudothelphusinae (
The Trichodactylidae is the smallest of all freshwater crab families (15 genera, 47 species) and represents only 4% of the world’s freshwater crab diversity. Despite this, the family is widely distributed and has representatives in 16 countries, most of which are in South America (Table
Colombia stands out as the most diverse and the most species rich part of the region (21 genera, 102 species, 2 families) (Table
The next most species-rich country is Mexico (17 genera, 67 species, 2 families) (Table
Brazil is the third most species-rich Neotropical country (16 genera, 50 species, 2 families) with a fauna that is dominated by trichodactylids (10 genera, 31 species, 2 subfamilies), and fewer pseudothelphusids (6 genera, 19 species, all Pseudothelphusinae, Kingsleyini). Venezuela is the fourth most species-rich Neotropical country (18 genera, 44 species, 2 families), made up of 11 genera and 35 species of pseudothelphusids (all Pseudothelphusinae, in three tribes, Hypolobocerini, Kingsleyini, and Strengerianini), and 7 genera and 9 species of trichodactylids (all Dilocarcininae).
The freshwater crab fauna of Ecuador (7 genera, 26 species, 2 families) includes 3 genera and 21 species of pseudothelphusids (all Pseudothelphusinae, Hypolobocerini), and 4 genera and 5 species of trichodactylids (all Dilocarcininae). Finally, Peru (11 genera, 22 species, 2 families) has a fauna dominated by trichodactylids (14 species and 8 genera, in 2 subfamilies Dilocarcininae and Trichodactylinae), with a smaller pseudothelphusid fauna consisting of 8 species and 2 genera (all Pseudothelphusinae in 2 tribes Kingsleyini and Hypolobocerini). Freshwater crabs of both families are completely absent from Chile. Despite warm subtropical climates freshwater crabs are absent in many islands of the Caribbean including Jamaica, The Cayman Islands, The Bahamas, Grenada, Antigua, and Anguilla.
When distribution patterns are considered at the genus level (Table
Thirteen (out of 34) pseudothelphusid freshwater crab genera and 28 (out of 283) species have a wide distribution that easily exceeds 20,000 km2 and includes more than one country. Notably, Fredius reflexifrons is found in six countries (Brazil, French Guiana, Guyana, Peru, Suriname, Venezuela), Potamocarcinus magnus is found in five countries (Mexico, Guatemala, Honduras, El Salvador, Costa Rica), and Kingsleya latifrons (Guyana, French Guiana, Suriname, Brazil) and Raddaus bocourti (Mexico, Belize, Guatemala, El Salvador) are found in four countries. Other widespread species found in three countries include Potamocarcinus armatus (Mexico, Guatemala, Nicaragua), P. richmondi (Nicaragua, Costa Rica, Panama), Fredius denticulatus (Brazil, French Guiana, Suriname) and F. fittkaui (Venezuela, Guyana, Brazil), and Prionothelphusa eliasi (Brazil, Colombia and Venezuela). Finally, 17 widespread species are found in two countries: Rodriguezus garmani (Trinidad and Tobago, Venezuela), Fredius beccarii (Guyana, Venezuela), Zilchia zilchi (El Salvador, Honduras), Hypolobocera caputii and Moritschus henrici (both Ecuador, Peru), Ptychophallus exilipes (Costa Rica, Panama), Hypolobocera bouvieri angulata, Orthothelphusa holthuisi (Colombia, Venezuela), and Hypolobocera exuca, Lindacatalina latipenis, L. orientalis, and L. sumacensis (all Colombia, Ecuador), Fredius estevisi and F. platyacanthus (Brazil, Venezuela), Kingsleya siolii (Brazil, Suriname), Zilchia aspoekorum (Belize, Mexico), and Raddaus tuberculatus (Guatemala, Mexico).
The majority of pseudothelphusids (22 species) that have a widespread distribution exceeding 20,000 km2 are assessed as Least Concern. However, there are some species with a small distributional range that spans the border between two neighboring countries that are assessed as either Vulnerable: Hypolobocera exuca (Colombia, Ecuador), Kingsleya siolii (Brazil, Suriname) and Zilchia aspoekorum (Belize, Mexico), or Data Deficient: Fredius platyacanthus (Brazil, Venezuela), Lindacatalina latipenis and L. sumacensis (both Colombia, Ecuador), Orthothelphusa holthuisi (Colombia, Venezuela), and Ptychophallus exilipes (Costa Rica, Panama).
Some 8 out of 15 trichodactylid freshwater crab genera and 20 out of 47 species have a wide distributional range exceeding 20,000 km2 that spans more than one country: all are assessed as Least Concern. Notably, Valdivia serrata is found in nine countries (Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela, Guyana, Suriname, French Guiana), Poppiana dentata in eight countries (Brazil, Colombia, French Guiana, Guyana, Nicaragua, Suriname, Trinidad and Tobago, Venezuela), and Sylviocarcinus pictus in seven countries (Colombia, Brazil, Bolivia, Peru, Argentina, French Guiana, Guyana). Dilocarcinus pagei is found in six countries (Argentina, Brazil, Bolivia, Colombia, Paraguay, Peru), and Sylviocarcinus devillei and Moreirocarcinus emarginatus are both found in 5 countries (Bolivia, Brazil, Colombia, Ecuador, and Peru; and Brazil, Colombia, Ecuador, Peru, and Venezuela respectively). Four species are found in four countries: Trichodactylus kensleyi (in Argentina, Brazil, Paraguay and Uruguay) and Poppiana argentiniana, Valdivia camerani, and Trichodactylus borellianus (in Argentina, Bolivia, Brazil, and Paraguay). Seven species are found in three countries (Rotundovaldivia latidens, Sylviocarcinus maldonadoensis, S. australis, Trichodactylus faxoni, T. panoplus, Valdivia cururuensis and Zilchiopsis oronensis), four species are found in two countries (Bottiella niceforei, B. cucutensis, Forsteria venezuelensis, T. quinquedentatus), and three species are found in one country (Trichodactylus petropolitanus, Valdivia novemdentata, and Zilchiopsis collastinensis).
Freshwater crabs are found in all major habitat types in the Neotropics (
Similarly the dominance of Trichodactylidae in the Amazon, Orinoco, Paraguay, and Parana River basins and their absence from Chile and from aquatic ecosystems at high altitudes in the Andes elsewhere in South America reflects their preference for an aquatic, rather than a semiterrestrial life (
Twenty-four species of neotropical freshwater crabs are found in caves (22 pseudothelphusids and two trichodactylids), and are either fully adapted to a life in caves, or are visitors to caves and have a distribution that also includes surface waters (Table
Species of Neotropical freshwater crabs that are associated with caves, and the country where each species occurs. The family, subfamily/tribe for each species are also shown, together with its IUCN Red List conservation status. LC = Least Concern, EN = Endangered, DD = Data Deficient. For explanation of Red List categories see
Family | Tribe | Species | Country | Cons. Status |
---|---|---|---|---|
Pseudothelphusidae | Strengerianini | Neostrengeria charalensis | Colombia | LC |
Pseudothelphusidae | Strengerianini | Neostrengeria sketi | Colombia | DD |
Pseudothelphusidae | Hypolobocerini | Achlidon puntarenas | Costa Rica | DD |
Pseudothelphusidae | Epilobocerinae | Epilobocera cubensis | Cuba | LC |
Pseudothelphusidae | Hypolobocerini | Phrygiopilus acanthophallus | Guatemala | DD |
Pseudothelphusidae | Potamocarcinini | Typhlopseudothelphusa juberthiei | Guatemala | DD |
Pseudothelphusidae | Potamocarcinini | Zilchia falcata | Guatemala | DD |
Pseudothelphusidae | Potamocarcinini | Typhlopseudothelphusa acanthochela | Belize | DD |
Trichodactylidae | Trichodactylinae | Avotrichodactylus constrictus | Mexico | LC |
Trichodactylidae | Trichodactylinae | Rodriguezia mensabak | Mexico | DD |
Pseudothelphusidae | Hypolobocerini | Phrygiopilus montebelloensis | Mexico | DD |
Pseudothelphusidae | Hypolobocerini | Phrygiopilus yoshibensis | Mexico | DD |
Pseudothelphusidae | Potamocarcinini | Odontothelphusa monodontis | Mexico | DD |
Pseudothelphusidae | Potamocarcinini | Potamocarcinus leptomelus | Mexico | DD |
Pseudothelphusidae | Pseudothelphusini | Pseudothelphusa mexicana | Mexico | DD |
Pseudothelphusidae | Pseudothelphusini | Tehuana complanata | Mexico | DD |
Pseudothelphusidae | Potamocarcinini | Typhlopseudothelphusa hyba | Mexico | DD |
Pseudothelphusidae | Potamocarcinini | Typhlopseudothelphusa mocinoi | Mexico | EN |
Pseudothelphusidae | Potamocarcinini | Sylvathelphusa cavernicola | Mexico | * |
Pseudothelphusidae | Potamocarcinini | Villalobosus lopezformenti | Mexico | DD |
Pseudothelphusidae | Epilobocerinae | Epilobocera sinuatifrons | Puerto Rico | LC |
Pseudothelphusidae | Strengerianini | Chaceus caecus | Venezuela | DD |
Pseudothelphusidae | Strengerianini | Chaceus turikensis | Venezuela | DD |
Pseudothelphusidae | Pseudothelphusini | Rodriguezus garmani | Venezuela | LC |
The majority of freshwater crab species found in Colombia (81%) are country endemics: 78 species of pseudothelphsids and 5 species of trichodactylids (
Countries that host endemic species of Neotropical freshwater crabs. First number indicates the number of species of Pseudothelphusidae (P), the second number indicates the same data for the Trichodactylidae (T).
Country | No. Endemic Sp. (P, T) |
---|---|
Colombia | 78, 5 |
Mexico | 62, 4 |
Venezuela | 22, 0 |
Panama | 12, 1 |
Ecuador | 11, 0 |
Costa Rica | 9, 0 |
Cuba | 9, 0 |
Guatemala | 9, 0 |
Brazil | 7, 10 |
Peru | 6, 3 |
El Salvador | 3, 0 |
Nicaragua | 3, 0 |
Belize | 2, 0 |
Dominican Republic | 2, 0 |
Guyana | 2, 0 |
Haiti | 1, 0 |
Honduras | 1, 0 |
Suriname | 1, 0 |
Trinidad | 1, 0 |
Bolivia | 0, 1 |
The conservation status of the 298 species of freshwater crabs known from the Neotropical region in 2009 was evaluated against the
Summary of the Red List assessments of the two families of Neotropical freshwater crabs based on data from
Family | Total Sp. | Assessed | Thr. | Thr. (%) | VU | EN | CR | LC | NT | DD |
---|---|---|---|---|---|---|---|---|---|---|
Pseudothelphusidae | 251 | 111 | 38 | 34.2 | 33 | 3 | 2 | 72 | 1 | 140 |
Trichodactylidae | 47 | 39 | 4 | 10.3 | 3 | 1 | 0 | 35 | 0 | 8 |
Total | 298 | 150 | 42 | 28.3 | 36 | 4 | 2 | 107 | 1 | 148 |
Summary of the countries in the Neotropical region that have threatened species of freshwater crabs based on data from
Country | Total Sp. | Assessed | Thr. | Thr. (%) | VU | EN | CR | LC | NT | DD |
---|---|---|---|---|---|---|---|---|---|---|
Colombia | 101 | 60 | 14 | 23.3 | 13 | 0 | 1 | 45 | 1 | 41 |
Venezuela | 42 | 31 | 7 | 22.6 | 7 | 0 | 0 | 24 | 0 | 11 |
Mexico | 63 | 19 | 6 | 31.6 | 2 | 3 | 1 | 13 | 0 | 44 |
Ecuador | 27 | 19 | 5 | 36.8 | 5 | 0 | 0 | 12 | 0 | 8 |
Peru | 25 | 21 | 3 | 14.3 | 3 | 0 | 0 | 0 | 0 | 4 |
El Salvador | 8 | 6 | 2 | 33.3 | 2 | 0 | 0 | 4 | 0 | 2 |
Costa Rica | 13 | 7 | 2 | 28.6 | 2 | 0 | 0 | 5 | 0 | 6 |
Brazil | 45 | 38 | 2 | 10.5 | 1 | 1 | 0 | 34 | 0 | 7 |
Suriname | 11 | 10 | 1 | 10.0 | 1 | 0 | 0 | 0 | 0 | 1 |
Honduras | 6 | 6 | 1 | 33.3 | 1 | 0 | 0 | 4 | 0 | 0 |
Haiti | 1 | 1 | 1 | 100.0 | 1 | 0 | 0 | 0 | 0 | 0 |
Guatemala | 13 | 7 | 1 | 28.6 | 1 | 0 | 0 | 5 | 0 | 6 |
Dominican Rep. | 2 | 2 | 1 | 100.0 | 1 | 0 | 0 | 0 | 0 | 0 |
Cuba | 9 | 9 | 1 | 11.0 | 1 | 0 | 0 | 0 | 0 | 0 |
Threatened species of Neotropical freshwater crabs. P = Pseudothelphusidae, T = Trichodactylidae. For explanation of Red list categories see
Family/Subfamily/Tribe | Taxon | IUCN Red List Category | Distribution |
---|---|---|---|
T. (Trichodactylinae) | Trichodactylus crassus | EN B1ab(iii) | Brazil |
P. (Kingsleyini) | Kingsleya siolii | VU B1ab(iii); D2 | Brazil, Suriname |
P. (Kingsleyini) | Fredius platyacanthus | VU B1ab(iii); D2 | Brazil, Venezuela |
P. (Kingsleyini) | Fredius stenolobus | VU B1ab(iii); D2 | Brazil, Venezuela |
P. (Hypolobocerini) | Hypolobocera alata | VU B1ab(iii); D2 | Colombia |
P. (Hypolobocerini) | Hypolobocera andagoensis | VU B1ab(iii); D2 | Colombia |
P. (Hypolobocerini) | Hypolobocera barbacensis | VU B1ab(iii); D2 | Colombia |
P. (Hypolobocerini) | Hypolobocera cajambrensis | VU B1ab(iii); D2 | Colombia |
P. (Hypolobocerini) | Hypolobocera rotundilobata | VU B1ab(iii); D2 | Colombia |
P. (Hypolobocerini) | Hypolobocera velezi | VU B1ab(iii); D2 | Colombia |
P. (Hypolobocerini) | Moritschus altaquerensis | VU B1ab(iii); D2 | Colombia |
P. (Kingsleyini) | Fredius granulatus | VU B1ab(iii); D2 | Colombia |
P. (Strengerianini) | Chaceus ibiricensis | VU B1ab(iii)+2ab(iii); D2 | Colombia |
P. (Strengerianini) | Strengeriana antioquensis | CR B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) | Colombia |
T. (Dilocarcininae) | Bottiella medemi | VU B1ab(iii)+2ab(iii) | Colombia |
P. (Hypolobocerini) | Hypolobocera exuca | VU B1ab(iii); D2 | Colombia, Ecuador |
P. (Hypolobocerini) | Lindacatalina sumacensis | VU B1ab(iii); D2 | Colombia, Ecuador |
T. (Dilocarcininae) | Bottiella cucutensis | VU B1ab(iii)+2ab(iii | Colombia, Venezuela |
P. (Potamocarcini) | Allacanthos pittieri | VU B1ab(iii); D2 | Costa Rica |
P. (Potamocarcini) | Ptychophallus tristani | VU B1ab(iii)+2ab(iii); D2 | Costa Rica |
P. (Epilobocerinae | Epilobocera wetherbeei | VU B1ab(iii); D2 | Dominican Republic |
P. (Hypolobocerini) | Hypolobocera delsolari | VU B1ab(iii); D2 | Ecuador |
P. (Hypolobocerini) | Hypolobocera rathbuni | VU B1ab(iii); D2 | Ecuador |
P. (Hypolobocerini) | Moritschus ecuadorensis | VU B1ab(iii); D2 | Ecuador |
P. (Hypolobocerini) | Elsalvadoria zurstrasseni | VU B1ab(iii)+2ab(iii); D2 | El Salvador |
P. (Hypolobocerini) | Raddaus mertensi | VU D2 | El Salvador, Guatemala, Honduras |
P. (Hypolobocerini) | Phrygiopilus acanthophallus | VU B1ab(iii); D2 | Guatemala |
P. (Epilobocerinae) | Epilobocera haytensis | VU B1ab(iii) | Haiti, Dominican Rep. |
P. (Potamocarcini) | Potamocarcinus roatensis | VU D2 | Honduras |
P. (Potamocarcini) | Potamocarcinus hartmanni | VU B1ab(ii)+2ab(ii); D2 | Mexico |
P. (Potamocarcini) | Typhlopseudothelphusa mocinoi | EN B1ab(iii)+2ab(iii) | Mexico |
P. (Pseudothelphusini) | Tehuana lamothei | EN B1ab(ii,iii)+2ab(ii,iii) | Mexico |
P. (Pseudothelphusini) | Tehuana poglayenorum | EN B1ab(ii,iii)+2ab(ii,iii) | Mexico |
P. (Pseudothelphusini) | Tehuana veracruzana | CR B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) | Mexico |
T. (Trichodactylinae) | Avotrichodactylus oaxensis | VU B1ab(iii)+2ab(iii) | Mexico |
P. (Hypolobocerini) | Hypolobocera gracilignatha | VU D2 | Peru |
P. (Hypolobocerini) | Hypolobocera lamercedes | VU B1ab(iii); D2 | Peru |
P. (Hypolobocerini) | Hypolobocera peruviana | VU D2 | Peru |
P. (Kingsleyini) | Microthelphusa forcarti | VU B1ab(iii); D2 | Venezuela |
P. (Kingsleyini) | Neopseudothelphusa fossor | VU B1ab(iii); D2 | Venezuela |
P. (Kingsleyini) | Rodriguezus trujillensis | VU B1ab(iii)+2ab(iii); D2 | Venezuela |
With only 42 out of 298 species of Neotropical freshwater crabs known in 2009 assessed as threatened with global extinction (Tables
Threats to Neotropical freshwater crabs include habitat destruction driven by increasing agriculture, the demands of increasing industrial development, and the alteration of fast flowing rivers for the creation of hydroelectric power (
This study confirms that freshwater crabs are completely absent from all parts of the Nearctic region (even in the neighboring warmer parts of northern Mexico and southern Florida, USA), and that the northern limits of their distribution coincide with the Nearctic/ Neotropical boundary in Mexico and the presence of arid regions lacking permanent freshwaters (i.e., the Sonoran and Chihuahuan Deserts). Species richness of freshwater crabs increases south of this boundary in Mexico and reaches a peak in the States of Veracruz, Tabasco, Oaxaca, and Chiapas. The uneven pattern of species-richness – high in Mexico, low in Central America, and high in Colombia – is difficult to explain by simply invoking an even spread of species out of a center of origin somewhere in Colombia–Venezuela (
The Neotropics are the second most diverse region in the world for freshwater crabs, and there are 42 species from 14 countries within this region that may be threatened with extinction. The finding that 34% of pseudothelphusids and 10% of trichodactylids are threatened, and that many others are poorly known, can be used to develop a conservation strategy for these species, and supply a focus for future research efforts (
The expert contributions of Célio Magalhães, Martha Campos and the second and third authors to the global assessment for the Neotropical freshwater crabs are recognized here. Amy Peterson (Northern Michigan University, USA) is thanked for her assistance with the georeferencing of large numbers of pseudothelphusid and trichodactylid localities. Gema Armendáriz and Benjamin Quiroz (Instituto de Biología, UNAM, Mexico) are thanked for adding records to the freshwater crab database and for creating the maps.