c. Alta VeraPaz Region (**Figure 4**)

b. Yucatan Peninsula (**Figure 3**)

*Natural History and Ecology of Mexico and Central America*

**Freshwater habitats**

*Typhlatya campechae Procambarus* sp. Anchialine habitats *Barbouria cubensis Anchialocaris paulini Agostocaris bozanici Agostocaris zabaletai Yagerocaris cozumel Triacanthoneus akumalensis Parhippolyte sterreri Janicea antiguensis Calliasmata nohochi Procaris mexicana Typhlatya dzilamensis Typhlatya pearsei Xibalbanus cozumelensis Xibalbanus tulumensis Xibalbanus fuchscockborni Metacirolana mayana*

**Table 2.**

**46**

**Crustaceans Fishes**

*Checklist of subterranean fauna taxa of the Yucatan peninsula region.*

*Creaseria morleyi* –Cosmopolitan species *Opisternon infernale Typhlatya mitchelli* –Cosmopolitan species *Ogilbia pearsei*

This area involve three Mexican states, is the longest area in the Southern of Mexico with a major caves formations involve the semi-dry, dry and flooded caves, in those closed to coast with sea water and freshwater subterranean interactions are called anchihaline systems, and their fauna is complete different to those with all freshwater. In the Yucatan Peninsula the maximum elevation is in Ticul Mountains, with 300 masl, However according with the different geological times that this Peninsula emerge there are at less five subregional areas, where the tropical forest are the most source of energy to maintenance the live in underground. The fishes more representative in the region are catfishes, *Rhamdia guatemalensis*, *Opisternon infernale* and *Ogilbia pearsei*, all them in freshwater, in the same conditions the crustaceans more abundant are *Creaseriella anops* (isopod), *Creaseria morleyi* and *Typhlatya mitchelli* and *Typhlatya pearsei*. Whilst, in anchialine systems there are *Barbouria cubensis, Agostocaris bozanici, Agostocaris zabaletai, Anchialocaris paulini, Procaris mexicana, Parhippolyte stereri, Yagerocaris cozumel,*

*Xibalbanus tulumensis, Xibalbanus cozumelensis* and *Xibalbanus fuchscockborni,*

*Creaseriella anops* (Isopod) Cosmopolitan species *Rhamdia guatemalensis* –Cosmopolitan species

This area comprised the Mountains Chains that slope drainage to Gulf of Mexico, there are a continuum of Mountains from Chiapas, and they are formed mainly by karstic soil, and the elevations go to 2000 m from Río Salinas and Río Xcán, that drainage to Usumacinta river in Mexico and to Cahabon river that go to Izabal Lake. In they are the main cave formations are in the Lanquin Area, and the springs from different rivers such the Hunalye, Cahabon, Xcán and others. The species reported in there are: freshwater prawns *Macrobrachium vicconi* in the entrance of spring of Hunalye without cave adaptations, *Macrobrachium* spp. (in description process), blind crabs, from Pseudothelphusidae family, and catfishes from *Rhamdia* genus. The tropical forest is the most common adjacent ecosystems and the bat activity to carried energy inside the caves is the principal source to maintenance the ecological function from these underground ecosystems. In this case all species was collected by authors.

#### **Figure 4.**

*Caves from Alta Verapaz and Peten regions in Guatemala.- the red points represent each entrance to subterranean systems.*

d. Petén Region (**Figure 4**)

This area is part of the Yucatan Peninsula base, where the elevations are less evident, from 350 to 50 masl, and the drainage to underground by karstic soil of water is more representative, here the caves are on floor level, and local people as water source use them. In this area the principal species are freshwater prawns *Macrobrachium* and crabs from Pseudothelphusidae family. They are not showed cave life adaptations. In this region all animals was confirmed by fieldwork from authors.

e. Chiquibul Region (**Figure 5**)

In Belize, there are several areas with karstic composition in the soil but only around of Mountains Systems has been recorded caves with long formations. Is important mentioned that close to Mexican border the soils is too similar to rest of Yucatan Peninsula and the potential to found caves or even cenotes is high. However, the caves recorded in Belize are mainly in Chiquibul region among 150 to 800 msal and in Islands and Cays where has been recorded anchialine systems. In there some crustaceans could be found as *Macrobrachium catonium*,*Typhopseudothelphusa acanthochela* and fishes from *Rhamdia laticauda*, however there are in description two new species of *Macrobrachium* species and one crab from the same family. In the anchialine systems has been reported *Xibalbanus cockei.* Jill Yager author that described it confirmed only this last species.

#### **4.2 Ecological conditions to freshwater and anchialine habitats**

The geological history of this region has two main sections in first instance the Mountain Systems Development in the different geological times was producing a new subterranean habitats to some freshwater groups invaded these sites with a consequently a new opportunity to speciation but they could be seen as a biological subterranean corridor, because these species have the same selection pressures and the changes among them are so closed. However, as has been reported each cave is a new chance to produce some changes in the adaptation as outcome of isolation procedure that considering this the different species of freshwater prawns, crayfish, or crabs, in these places in average the oxygen are lower between 2 to 3 mg/l with a saturation of 60%; at same time the pH is around the neutral values with some peaks to alkalinity, normally all with freshwater conditions and values of temperature around the 18 to 22°C, in all these places the measures were taken with low depth.

However, the Yucatan Peninsula have a different origin and the different ways to colonised this subterranean habitats, our results show that in the enormous plate the species are cosmopolitan but exclusively in they are as *Creaseria morleyi, Typhlatya mitchelli*. Another big faunistic group is from anchialine group that their marine habitats conditions there are species so very primitive as Remipedia with at less three species around the coastal caves, or different decapod species that has been reported with different origins, as *Procaris mexicana, Anchialocaris paulini*, *Agostocaris bozanici, A. zabaletai,Typhlatya dzilamensis, Barbouria cubensis*, or even *Calliasmata nohochi* and *Yagerocaris cozumel*. In this places where the anchialine habitats are present the salinity is closed to marine conditions 36 ups, with pH values clearly to alkalinity between 8 and 9, the oxygen dissolved are close to hypoxic conditions 0.15 to 0.3 mg/l, with 5 or 10% of saturation. The temperature is around the 24°C [28] an example of these behaviour is showed in the **Figure 6** to Cenote Chempita.

**4.3 Interrelationships among the karstic areas (richness analysis and biological**

*Caves from Belize karst regions. The red points represent each entrance to subterranean systems.*

*Tropical Subterranean Ecosystems in Mexico, Guatemala and Belize: A Review of Aquatic…*

*DOI: http://dx.doi.org/10.5772/intechopen.97694*

The five karstic areas involved, show a differences in the species composition and their numbers, in some places only one specimens are located, whilst another there are hundred or even miles (**Table 3**). However, in the first view or richness the Yucatan Peninsula is more diversity in the crustaceans but have two different habitats and in the freshwater the *Creaseria morleyi* and *Creaseriella anops* are too cosmopolitan; whilst in the coastal areas the anchialine habitats allow that species

**subterranean corridor)**

**Figure 5.**

**49**

*Tropical Subterranean Ecosystems in Mexico, Guatemala and Belize: A Review of Aquatic… DOI: http://dx.doi.org/10.5772/intechopen.97694*

**Figure 5.** *Caves from Belize karst regions. The red points represent each entrance to subterranean systems.*
