Flora
Los Tuxtlas has enormous biodiversity that is rivaled by few other areas in Mexico. Nine forest vegetation types have been identified according to Sousa (1968), including deciduous forest, oak forest, mangrove, savannah, high evergreen forests, evergreen lowland forests, mid-elevation semi-deciduous forest, pine forest and coastal vegetation. The forests have a great variety of fauna including species endemic to tropical and boreal forests. Due to its immense ranges in elevation (from the coast to the tops of the volcanoes), the reserve is an example in Mexico where multiple forest types are contained in one region. In general, the Neotropical flora of Las Tuxlas is specific to the Caribbean region and the Gulf of Mexico Coastal Province (Rzedowski 1986, Estrada & Coates-Estrada 1999).
The region has approximately 2,695 species of vascular plants, including 42 subspecies and 102 varieties, represented in 214 families and 6 classes of plants. Dicots represent the majority of families and species (69% and 68% respectively). Both monocots and ferns represent 29% of the families, and comprise 21% and 10% of park species, respectively. The lycopodes and selaginella, woody gymnosperms, and cycads are characterized by five families, representing only 2% of the families and 1% of the total species (Ibarra et al 1997, Ramirez 1999).
Los Tuxtlas is one of the five areas in Mexico with the highest rates of endemism, with about 10% of the trees being endemic to the region's hot humid zone (Wendt 1993, Rzendowski 1991). Although further research is necessary to determine the full extent of their range, current data suggests several species could be considered endemic to the reserve: Thelypteris rachyflexuosa, Solenophora tuxtlensis, Iiinga sinacae, Begonia sousae, Pouteria rhynchocarpa, Mormodes tuxtlensis, Ruellia tuxtlensis, Tridineris tuxtlensis, Aristolochia veracruzana, Inga lacustris, Parathesis calzadae, Parathesis neei, Parathesis tuxtlensis, and Rondeletia tuxtlensis (Ibarra et al. 1997, Ramirez 1999).
Other species considered endemic to the Sierra Santa Marta region are Aristolochia impudica, Dichapetalum mexicanum, Salivia tuxtlensis, Parthesis pajapensis, and Chamaedora hooperiana (Ramirez 1999).
The Cycada family (Zamiaceae) is the only one in the region with four species receiving some degree of international protection. Three of the species are considered threatened, Certozamia mexicana var. robusta, Zamia furfuraceae, and Zamia loddigesii, while Certozamia miqueliana is critically endangered. Additionally, C. mexicana, C. miqueliana, and Z. furfuraceae are considered endemic species. Six species from other families are also considered endemic and five are critically endangered: Chamaedora tuerckheimii, Chamaedoreae tenella, Aporocactus leptophis, Olmeca recta and Olmeca reflexa. Chamaedorea alternans is also listed as threatened.
Fauna
The fauna of the region is as rich as the flora. The ichthyofauna of Los Tuxtlas includes species distributed between freshwaters and estuaries. 109 species, with 78 genera in 36 families have been recorded in the park. The family of fish Characidae includes is locally recognized as "pepescas." Within this family, Bramochrarax caballeroi is endemic to Lake Catemaco. Astyanax fasciatus is an exotic species from South American. Of the family Atherinidae, locally referred to as "charales," Atherinella ammophila is endemic to the region near the La Palma River.
The marine fauna in the continental waters represent 72 % of the total ichthyofauna of the region. It is comprised of 63 genus and 33 families (Espinosa 1997, Fuentes & Espinosa 1997). Four species of marine origin are recognized as accidentals, seven species are endemic, two species are exotic, and five species are threatened. However, according to the Official Mexican Standard for Ecology #059 of 1994, which lists species according to their threat categories (NOM-ECOL-059-1994), only Rhamdia guatemalensis and Priapella olmeca are considered threatened species, while Xiphophorus milleri is critically endangered. P. olmececae and X. milleri are considered endemic species.
The herpetofauna in the region represents an important percentage of the total number of species in Mexico (14.8% of the amphibians and 16.5% of the reptiles) (Flores-Villela 1993). Literature lists 166 species, represented in six orders and 33 families. Of these species, 24 are endemic to Mexico. Of these 24, 19 are exclusively found in Los Tuxtlas. Only Hemidactylus frenatus introduced from the Philippines, is considered exotic (Morales-Mavil et al 1995, Gonzalez et al. 1997). Of the 46 species of amphibians, 19 are protected under NOM-ECOL-059-1994, one is under special protection, and 18 are considered rare. Twenty-six species of reptiles are classified as rare, 11 are threatened, 18 are subject to special protection, and seven are critically endangered.
The 561 species of birds in the region include both terrestrial and marine species. These species include 21 orders, one suborder, 72 families, and eight subfamilies. Two endemic species have been reported: the long tailed sabrewing (Campylopterus excellens) and the Tuxtla quail-dove (Geotrygon carrikeri). Five endemic subspecies have also been reported: Empidonax flavescens imperturbatus, Myioborus miniatus molochinus, Atlapetesbrunneinucha apertus, Cholorospingis opthalmicus wetmorei and Vireolanius pulchellus ramosi (Lowery & Newman 1949, Coates-Estrada & Estrada 1985, Estrada et al 2000). In 1997, the World Conservation Union (IUCN) reported 30 species of birds classified as critically endangered and 55 as threatened. However, the Mexican system, NOM-ECOL-059-1994, protects 164 species: 55 are classified as rare, 46 are threatened, 12 are subject to special protection, and 11 are critically endangered (Winker 1997, Estrada & Coates-Estrada 1997). The king vulture (Saarcoramphus papa), the harpy eagle (Harpia harpyja), and the red macaw (Ara macao) are locally extinct.
The Los Tuxtlas Biosphere Reserve reported a total of 139 species of mammals, representing 30 % of Mexico's total. These are divided into 11 orders, 31 families, and 17 sub families (Martinez & Sanchez 1997, Coates Estrada & Estrada 1986). The NOM-ECOL-059-1994 considers 31 species located in Los Tuxtlas to be under some form of conservation. Furthermore, it ranks the howler monkey (Alouatta palliata mexicana) as an endemic species. Seven mammal species are classified as threatened: porcupine (Sphiggurus mexicanus), nutria (Lutra longicaudis), jaguarondi (Herpailurus yaguarondi), and little grison (Galictis vittata). Eleven species are critically endangered, including the spider monkey (Ateles geoffroy), the howler monkey (Alouatta palliata mexicana), the banded anteater (Tamandua mexicana), and the tayra (Eira barbara); 13 species are considered rare, including the woolly opossum (Caluromis derbianus) the false vampire bat (Vampirum spectrum), the cacomiztle raccoon (Baassarscus sumichrasti), and the kinkajou (Potos flavus).
International organizations, including IUCN, report 17 species at risk. The puma (Puma concolor) is Critically Endangered, the rice rat (Orizomys melanotis) is classified as Data Deficient, the Mexican long-nosed bat (Leptonycteris nivalis) is considered Critically Endangered, the Mexican agouti (Dasyprocta mexicana) and the bat (Lonchorhina aurita) are considered Threatened, and the bat (Bauerus dubiaquercus) and the howler monkey (Alouatta palliaata mexicana) are considered Vulnerable.
Some of the larger mammals, including the jaguar (Panthera onca), the puma (Puma concolor), the tapir (Tapirus bairdii), the red brocket deer (Mazama amaericana), the white-lipped peccary (Tayassu pecari), and the west Indian manatee (Trichechus manatus) in the Sontecomapan Lake, have been locally exterminated due to illegal deforestation, uncontrolled hunting, and the illegal commerce of wild animals (Coates-Estrada & Estrada 1986).
The insects reported in the region fall within 72 families, 46 subfamilies, 88 tribes, 707 genera, and 1,117 species. Additionally, 172 species of butterflies have been reported (Moron 1992, Raguso &Lorente 1997). These included 24 newly reported species for Mexico in the case of the family Syrphidae and four new species described within the group of the fireflies, in the genera Phaenolis, Aspisoma, Photinus, and Photuris (Navarrete-Heredia 1997, Zaragoza 1997, Navarrete-Heredia 191, Estrada & Coates-Estrada 1998).
