History of Montezuma Well
The land around Montezuma Well has been home to many prehistoric groups of people since as early as 11,000 CE. The first historical groups came to the Verde Valley after Arizona became a territory in 1863. Some accounts say Spanish settlers traveled through earlier, in the 1500s, but did not settle in the area.
Wildlife of Montezuma Well
The water in Montezuma Well has unusually high levels of dissolved carbon dioxide and arsenic, as well as calcuim and other chemicals. This combination prevents fish from living within the Well, but is also responsible for the evolution of the five endemic (native plant or animals that are restricted to a certain place) species found within the Well.
Diatom (Caloneis latiuscular var. reimeri, Cyclotella pseudostelligera f. parva, and Gomphonema montezumense): Diatoms are photosynthesizing algae with intricate silicate cell walls. Scientists think the three diatoms found within the Well may have appeared around 8,000 years ago (Blinn 2008).
Amphipod (side-swimmers; Hyallela montezuma and H. azteca): Amphipods can be found along the weedy margins of the Well. The amphipod species that live here are susceptible to parasitic infection by worms. During infection, the amphipods become slower and less prone to seek camoflauge, and more likely to be found in the nearshore vegetation, where they come food for water bugs, water scorpions, and waterfowl (O'Brien et al. 2002). The amphipod species that live in Montezuma Well become a keystone species because of its role in the food web.
Leech (Motobdella montezuma and two Helobdella species): The three species of leeches that live in the Well hunt the amphipods, ascending to the surface to feed an hour or two after sunset (Blinn 2008). They track their prey by detecting vibrations in the water using special structures called sensilla (Govedich and Bain 2005). These structures are so sensitive that the leeches can selectively hunt, choosing juveniles of adults. Each leech eats between 12-16 amphipods per night, swallowing their prey whole and then using enzmes to digest the internal body fluids. (Blinn 2008; Govedich and Bain 2005).
A water scorpion (Ranatra montezuma): Water scoripions live in the weed bed along the shore of the Well, entering the open water at night to feed. It uses a sharp beak to pierce and suck internal body fluids from its adult prey, the amphipods (Blinn 2008; Blinn et al. 1982). The water scorpion buries its eggs in soft, partially decayed plant tissue to hide them from predators during the months of December through February (Blinn 2008).
A spring snail (Pyrgulopsis montezuma): The spring snail lives in the swallet and associated limestone and moss habitats along the shoreline (Blinn 2008). This species is currently vulnerable and until recently, were potentially threatened by the red-ear slider turtles introduced to the Well in the late 1960s or 1970s (Cordeiro 2012).This particular snail cannot survive outside the Well, requiring at least 50 mg per liter of carbon dioxide in the water - ten times that found in most standing waters (Blinn 2008).
The pondweed most common and visible in Montezuma Well is also likely endemic but unnamed (NPS 1992). According to Cole (1965), the Montezuma Well Potamogeton species has stem anatomy like P. gramineus and upper anatomy like P. illinoiensis. The pondweed in Montezuma Well roots in sediments as deep as eight meters (about 26 feet) below the surface, which may be the deepest known for a Potamogeton species (Blinn 2008).
A Mud Turtle (Kinosternon sonoriense): The Mud Turtles found within the Well may be endemic to Montezuma Well (NPS 1992). If formally recognized, the mud turtles of Montezuma Well will be the third subspecies of K. sonoriense known in the greater Southwest, or perhaps a new species altogether.
Last updated: December 3, 2020