Motobdella montezuma

Motobdella montezuma
Scientific classification
Kingdom:	Animalia
Phylum:	Annelida
Class:	Clitellata
Subclass:	Hirudinea
Family:	Erpobdellidae
Genus:	Motobdella
Species:	M. montezuma
Binomial name
Motobdella montezuma (Davies, Singhal & Blinn, 1985) [1]
Synonyms [2]
Erpobdella montezuma Davies, Singhal & Blinn, 1985

Motobdella montezuma is a species of leech which is only found in Montezuma Well, central Arizona, United States. It is a nocturnal pelagic predator that feeds almost exclusively on the endemic amphipod Hyalella montezuma, which it detects using passive sonar and swallows whole.

Description

Adults of M. montezuma may reach a length of 71 mm (2.8 in) including the suckers at the front and rear.^[3]

Distribution

Montezuma Well

M. montezuma is closely related to the genus Erpobdella,^[4] which includes species that are widespread across North America from Alaska to Mexico.^[5] However, M. montezuma is only known to occur in a single pool, Montezuma Well, in the Montezuma Castle National Monument in Yavapai County, Arizona.^[6]

Ecology

Montezuma Well is too small to support a healthy population of fish, leaving an ecological niche of open-water predator free. Although there are a number of species of invertebrates living in the well, the diet of M. montezuma consists almost entirely of the endemic amphipod Hyalella montezuma.^[6]

Behavior

M. montezuma is nocturnal, resting at the bottom of the well during the day, when predatory waterfowl are present.^[7] As night falls, the leeches swim towards the surface and hunt amphipods near the surface; this is the only instance of a leech hunting in open water.^[7] Prey are detected by passive sonar, and swallowed whole. This pattern of diel vertical migration by a leech is only known to occur in Montezuma Well.^[7]

Life cycle

Like many other leeches, M. montezuma is hermaphroditic. Sexual reproduction results in two individuals fertilizing each other, and the resulting eggs are placed in a nutrient-filled cocoon. The cocoon is placed deep enough to avoid the attention of ducks and other predators, and the eggs hatch into self-sufficient juveniles.^[7]

References

1. ^ "Motobdella montezuma". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=568959. 
2. ^ "Erpobdellidae". Texas A&M University. http://insects.tamu.edu/research/collection/hallan/test/Annelida/Family/Erpobdellidae.txt. Retrieved April 19, 2010. 
3. ^ Fredric R. Govedich, Dean W. Blinn, Paul Keim & Ronald W. Davies (1998). "Phylogenetic relationships of three genera of Erpobdellidae (Hirudinoidea), with a description of a new genus, Motobdella, and species, Motobdella sedonensis". Canadian Journal of Zoology 76 (12): 2164–2171. doi:10.1139/cjz-76-12-2164. 
4. ^ James H. Thorp & Alan P. Covich (2001). Ecology and classification of North American freshwater invertebrates (2nd ed.). Academic Press. ISBN 9780126906479. 
5. ^ Roy T. Sawyer (1970). "Observations on the natural history and behavior of Erpobdella punctata (Leidy) (Annelida: Hirudinea)". American Midland Naturalist 83 (1): 65–80. http://www.jstor.org/stable/2424006. 
6. ^ ^{a b} Dean W. Blinn, Ronald W. Davis & Behrooz Dehdashti. "Specialized open water feeding by the leech, Erpodbella montezuma (Hirudinea)". Northern Arizona University. http://dana.ucc.nau.edu/~are-p/research/researchers/blinn.html. Retrieved April 19, 2010. 
7. ^ ^{a b c d} Fredric R. Govedich & Bonnie A. Bain (2005). "All about the leeches of Montezuma Well". National Park Service. http://www.nps.gov/moca/naturescience/upload/Montezuma_Well_Leeches.pdf. Retrieved April 19, 2010.