**5. Discussion**

The tropical subterranean aquatic biodiversity in Central America (Mexico, Guatemala & Belize) is higher in comparison with those temperate zones in Mexico even, because how has been described previously there are more taxa (**Figures 7** and **8**) [10, 21, 22, 29]. Although as well had been described, in other continents are described with more detail the taxa numbers by example Europe where the main factor to produce these numbers are the efforts occupied in exploring and registered these taxa [30]. Therefore, the diversity comparison among these regions are too difficult, because depends in first instance of the correct reports and the effort to exploring the areas, all these data are an approximately about that the current status of biodiversity [31], showed the status among this subterranean diversity in the tropics using some cave as examples but is not determinant but in the aquatic habitats the crustaceans are reported as main taxa. However, is evident that the freshwater groups colonised in first instance those habitats close the mountains in this biological subterranean corridor, there are another group that cluster the Yucatan Peninsula Region and due the different origin from the Mountain Systems allow that these species are cosmopolitan distribution [6]. Finally the anchialine species group are totally different and their relationships are more closely with Antilles fauna [32–35]. Even among the regions there are important differences in the diversity not only in the composition of genus or families, too in the number of species and in the specimens registered, by example due that the regions are big land extension is few possible that only one or two specimens were registered, is we check the numbers of index as Chao's or Burman & Overton the diversity estimated increase few because the taxa included in the analysis had a good representation in the area, someone are cosmopolitans in the same region.

with more relationships with another Caribbean Islands species live, and normally these species have a microdistribution and marine origin recent. Is evident that this

*representative of three water layers i) freshwater 0-16 m; brackish water 16–24m, and marine water 24–60 m.*

*Profile of Anchialine deep ecosystems. A) Temperature-Salinity, B) pH-Salinity; C) Oxygen Dissolved-Salinity; D) Oxygen concentration-Salinity. The cenote Chemita located in Cozumel Island, have a*

origin and their microdistribution are mainly in the locality type for several

In contrast in the Isthmus and Chiapas region the crustaceans have a freshwater

region the species that inhabiting, not share with another region.

*Natural History and Ecology of Mexico and Central America*

**Figure 6.**

**50**

even in the tropical dry caves there are some different according with the temperature and humidity that produce a major heterogeneity because these features are changing in relation with outside [37, 38], and in semi-dry caves these features have a relation with the oxygen inputs in the subterranean aquatic habitats. In the Anchialine caves the size of freshwater lenses are the main changes to energy entrance and the environmental stability [28]. Their ecological relation in these subterranean systems all in tropical conditions depends of course of their energy support and in this region there are two main ways, the alloctonous way using the biological and hydrological process [36] and for autochthonous way producing by chemolitotrophic procedures the energy using the chemosynthetic bacteria and support by use of methane and dissolved organic carbon [39–41]. In the first option the biological process involve bats that carry several seeds or insect debris, even they self when died; some trogloxene animals that sometimes entrance to these environments and died; but also by there are an important energy sources in cave entrance by the sun effects, where several plants growth and some cave insects go to entrance to feed and back to dark zones. In the second option the chemolitotrophic organisms has been reported on the walls or ceiling as Cueva de Villa Luz in Tabasco and even in some symbiosis with another animals using the electrons from sulphur origin or chemoorganotrophic as the methane decomposition to produce energy as been reported for some crustaceans [42, 43]. This energy source still are working in the different research groups to understand in first instance how is support the life, and the organic matter available could be the main evolutionary forces to different

*Representative cave fish species in the Mesoamerican region a)* Opisternon infernale*; b)* Ogilbia pearsei *(photo courtesy of Juan Carmona; c)* Rhamdia laticauda*; d) fish from Bithynidae family in anchialine*

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

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

process how as been reported by [15, 21, 44, 45].

**Figure 8.**

*ecosystems.*

**53**

#### **Figure 7.**

*Representative cave crustaceans species in the Mesoamerican region. a)* Procambarus *sp.; b)* Typhlopseudothelphusa acanthochela*; c)* Macrobrachium catonium*; d)* Creaseria morleyi *(courtesy by Erick Sosa); e)* Procaris mexicana*; f)* Anchialocaris paulini*; g)* Typhlatya *sp.; h)* Agostocaris zabaletai*; i)* Calliasmata nohochi*; j)* Barbouria cubensis*.*

By another aspect is the subterranean environments that in first instance was classified in dry, semi-dry, freshwater flooded, and anchialine caves as has been reported in several opportunities [36], but in recently studies has been reported that *Tropical Subterranean Ecosystems in Mexico, Guatemala and Belize: A Review of Aquatic… DOI: http://dx.doi.org/10.5772/intechopen.97694*

#### **Figure 8.**

*Representative cave fish species in the Mesoamerican region a)* Opisternon infernale*; b)* Ogilbia pearsei *(photo courtesy of Juan Carmona; c)* Rhamdia laticauda*; d) fish from Bithynidae family in anchialine ecosystems.*

even in the tropical dry caves there are some different according with the temperature and humidity that produce a major heterogeneity because these features are changing in relation with outside [37, 38], and in semi-dry caves these features have a relation with the oxygen inputs in the subterranean aquatic habitats. In the Anchialine caves the size of freshwater lenses are the main changes to energy entrance and the environmental stability [28]. Their ecological relation in these subterranean systems all in tropical conditions depends of course of their energy support and in this region there are two main ways, the alloctonous way using the biological and hydrological process [36] and for autochthonous way producing by chemolitotrophic procedures the energy using the chemosynthetic bacteria and support by use of methane and dissolved organic carbon [39–41]. In the first option the biological process involve bats that carry several seeds or insect debris, even they self when died; some trogloxene animals that sometimes entrance to these environments and died; but also by there are an important energy sources in cave entrance by the sun effects, where several plants growth and some cave insects go to entrance to feed and back to dark zones. In the second option the chemolitotrophic organisms has been reported on the walls or ceiling as Cueva de Villa Luz in Tabasco and even in some symbiosis with another animals using the electrons from sulphur origin or chemoorganotrophic as the methane decomposition to produce energy as been reported for some crustaceans [42, 43]. This energy source still are working in the different research groups to understand in first instance how is support the life, and the organic matter available could be the main evolutionary forces to different process how as been reported by [15, 21, 44, 45].

By another aspect is the subterranean environments that in first instance was classified in dry, semi-dry, freshwater flooded, and anchialine caves as has been reported in several opportunities [36], but in recently studies has been reported that

*b)* Typhlopseudothelphusa acanthochela*; c)* Macrobrachium catonium*; d)* Creaseria morleyi *(courtesy by Erick Sosa); e)* Procaris mexicana*; f)* Anchialocaris paulini*; g)* Typhlatya *sp.; h)* Agostocaris zabaletai*;*

*Representative cave crustaceans species in the Mesoamerican region. a)* Procambarus *sp.;*

*Natural History and Ecology of Mexico and Central America*

**Figure 7.**

**52**

*i)* Calliasmata nohochi*; j)* Barbouria cubensis*.*
