Gila topminnow (Poeciliopsis occidentalis)
Where Listed: WHEREVER FOUND
A small (2.5-5 cm), silvery, live-bearing, guppy-like fish without dark spots on the fins. Males in breeding color are black with yellow fins. There are two listed subspecies of the Sonoran topminnow (P. occidentalis); the Gila topminnow (P. o.occidentalis) of the Gila River basin and the Yaqui topminnow (P.o. sonoriensis) of the Rio Yaqui. Science recognizes these two forms as separate species.
- States/US Territories in which the Gila topminnow, Wherever found is known to or is believed to occur: Arizona , New Mexico
- US Counties in which the Gila topminnow, Wherever found is known to or is believed to occur: View All
- USFWS Refuges in which the Gila topminnow, Wherever found is known to occur:
Leslie Canyon National Wildlife Refuge, San Bernardino National Wildlife Refuge
- Countries in which the the Gila topminnow, Wherever found is known to occur: Mexico
- Additional species information
|Status||Date Listed||Lead Region||Where Listed|
|1967-03-11||Southwest Region (Region 2)||Wherever found|
» Federal Register Documents
|2008-03-20 00:00:00.0||73 FR 14995 14997||5-Year Reviews of 28 Southwestern Species|
|2007-04-23 00:00:00.0||72 FR 20134 20136||5-Year Reviews of 24 Southwestern Species|
|1967-03-11 00:00:00.0||32 FR 4001||Endangered Species List - 1967|
|Date||Title||Plan Action Status||Plan Status|
|1999-03-05||Draft Revised Recovery Plan for the Gila Topminnow||Recovery efforts in progress, but no implementation information yet to display||Draft Revision 1|
|Gila/Yaqui Topminnow (2 ssp.)||View Implementation Progress||Draft Revision 1|
|Date||Citation Page||Title||Document Type|
|2008-03-20||73 FR 14995 14997||5-Year Reviews of 28 Southwestern Species||
|2007-04-23||72 FR 20134 20136||5-Year Reviews of 24 Southwestern Species||
» Critical Habitat
No critical habitat rules have been published for the Gila topminnow.
» Conservation Plans
|HCP Plan Summaries|
|Pima County Multi-Species Conservation Plan, under Sonoran Desert Conservation Plan|
|Salt River Project Horseshoe and Bartlett HCP|
|SHA Plan Summaries|
|Aravaipa SHA for Gila topminnow and desert pupfish|
|Arizona Department of Transportation|
|Leslie Canyon Watershed SHA (Barboot/99-Ranch)|
|SHA for topminnows and pupfish in Arizona|
» Life History
Habitat requirements are broad. Topminnow prefer shallow, warm, fairly quiet waters in ponds, cienegas, tanks, pools, springs, small streams and the margins of larger streams. Dense mats of algae and debris along the margins of the habitats are an important component for cover and foraging. Substrates of organic muds and detritus also provide foraging areas. Species historically also occurred in backwaters of large rivers but is currently isolated to small streams and springs.
Topminnow are generalist feeders, utilizing detritus, plants, small crustaceans, and insect larvae. As previously noted, they will prey on their own young.
Movement / Home Range
Due to surface and groundwater developments that eliminated connectivity between aquatic habitats, topminnow have limited movement potential out of occupied habitats. Found below 4,500 feet of elevation.
Topminnow bear live young and two broods are carried simultaneously (one further along in development than the other). Brood size is from 1 to 20, and gestation time is 24-28 days. Breeding season is from January to August, with some populations capable of breeding all year if temperatures and food availability are suitable. Life span is approximately 1 year; however, this varies with season of birth and fluctuations in environmental conditions in the habitat. Cover is needed for new-born fish to protect them from predation by the adults.
Threats to the topminnow are from continued habitat loss due to water development, habitat degradation due to erosion from roads and damaged watersheds, and introduction of non-native aquatic species (fish, bullfrogs, and crayfish, but especiallt western mosquitofish) that prey on and compete with topminnow into the remaining habitats.
» Other Resources
NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.