Aquarium Volume: 100 L
Fish and invertebrates: Profundulus oaxacae, Physa sp.
Plants list: Bacopa monnieri, Heteranthera reniformis, Fissidens sp.,  Hydrocotyle verticillata, Eleocharis acicularis
Biotope description: This aquarium is based and built with elements of the natural habitat, it corresponds to the first pool that forms the stream “El Arco” corresponding to the sub-basin “San Lucas” watershed “Atoyac” in the state of Oaxaca, Mexico. On that site creator aquarium biotope he found the 6th population of endemic fish “Profundulus oaxacae” (species at risk of extinction), where he lives alone, does not share the pool with other fish species, perhaps in the case of the smallest population because only there could be located in the first pools of the stream, in the lower part has disappeared by the introduction and presence of Tilapia (Oreochromis spp.). The stream is formed in a ravine, where there is a small forest of oak (Quercus sp.), The type of rock is metamorphic slate type, trachytes, and sedimentary, so the gravel and sand comes from them and have irregular edges , being not too thin. Water runs off the slopes forming a small initial pool at the bottom where there is an abundance of oak leaves that are carried by air currents that form in the glen and rain. As for aquatic plants, you can find small patches of Bacopa monnieri arriving to emerge, some plants Heteranthera reniformis, and on the edge of the ground water is plentiful mosses of the genera Fissidens, Hydrocotyle verticillata, Eleocharis acicularis and some grasses.