Empetrichthys latos
Encyclopedia
Empetrichthys latos is a rare species of fish
in the family Goodeidae
, the splitfins. It is known by the common names Pahrump poolfish and Pahrump killifish, the former being more correct today. It is endemic to Nevada
in the United States, where it was limited to the Pahrump Valley
near the California border. It nearly became extinct
due to habitat destruction and no longer occurs there. It is a federally listed endangered species
of the United States.
This fish is about 7 cm (2.8 in) long. It has its dorsal and anal fins far back on its body and it lacks pelvic fins. The head is depressed in front and the mouth is wide. The jaws are unequal, the lower projecting farther than the upper. The fish is greenish on its back and silvery green on the belly. The male takes on a blue tinge during spawning.
It is omnivorous
, feeding on varied plant and animal material. Spawning is most common in spring but can occur at any time of the year when conditions are right. Adults are more active at night, but juveniles appear to be more active during the day. The native habitat of the fish was made up of pools and marsh
es. The water at one pool was a constant 24°C. This may be the optimal temperature for the species but it can tolerate a relatively wide range of temperatures. It has been noted to survive under a layer of ice during winter. The water is alkaline
.
This species is the only surviving member of genus Empetrichthys, the other, the Ash Meadows killifish
(Empetrichthys merriami), having become extinct in the 1940s. There were three subspecies
of E. latos, two of which are extinct today. Each occurred in a different spring
in the Pahrump Valley. The Raycraft Ranch springfish
(E. latos concavus) became extinct when its spring was destroyed in the 1950s. The Pahrump Ranch killifish (E. latos pahrump) disappeared when its spring was pumped dry in 1958. The remaining fish was known as E. latos latos, a name which has lost its meaning since it became the only surviving subspecies. It is now known simply as the Pahrump poolfish.
In 1975 the Pahrump poolfish was extirpated
from its habitat, Manse Spring, when it experienced competition
from the introduced
goldfish
, some vegetation was removed, and the spring dried up due to groundwater
pumping nearby. On noting its impending extinction, scientists and officials removed specimens of the fish and transplanted them into three pools in different locations in Nevada. When the official recovery plan for the species was published by the United States Fish and Wildlife Service
in 1980, it aimed to manage and protect the three transplanted populations. The fish has not been returned to its native habitat at Manse Spring because the area is under development and the water supply is not reliable.
Though the fish reproduced successfully and appeared to thrive in its new pools, it faced a number of challenges there. Flooding destroyed one of the pools, vandalism
killed specimens at another, and the unauthorized introduction of mosquitofish
and crawfish further threatened the fish. Some fish were transplanted into a reservoir
to replace the flooded population, but the USFWS had to intervene when Nevada State Parks officials planned to dredge the pond. Today the populations remain, but the habitat must be artificially maintained at times. As of 2004 only one population is stable. Threats still exist from groundwater pumping, vandalism, and introduced species. The USFWS still considers the species to be "in imminent danger of extinction" and is maintaining its endangered status.
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
in the family Goodeidae
Goodeidae
Splitfins, are a family, Goodeidae, of teleost fish endemic to Mexico and some areas of the United States. This family contains 40 species within 18 genera. The family is named after ichthyologist George Brown Goode.-Range and Geographic Distribution:...
, the splitfins. It is known by the common names Pahrump poolfish and Pahrump killifish, the former being more correct today. It is endemic to Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
in the United States, where it was limited to the Pahrump Valley
Pahrump Valley
Pahrump Valley is a Mojave Desert valley west of Las Vegas and the Spring Mountains massif in southern Nye County, Nevada, and eastern San Bernardino County, California. Pahrump, Nevada, is in the valley's center and the Tecopa and Chicago Valleys are immediately to the west...
near the California border. It nearly became extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
due to habitat destruction and no longer occurs there. It is a federally listed endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of the United States.
This fish is about 7 cm (2.8 in) long. It has its dorsal and anal fins far back on its body and it lacks pelvic fins. The head is depressed in front and the mouth is wide. The jaws are unequal, the lower projecting farther than the upper. The fish is greenish on its back and silvery green on the belly. The male takes on a blue tinge during spawning.
It is omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
, feeding on varied plant and animal material. Spawning is most common in spring but can occur at any time of the year when conditions are right. Adults are more active at night, but juveniles appear to be more active during the day. The native habitat of the fish was made up of pools and marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es. The water at one pool was a constant 24°C. This may be the optimal temperature for the species but it can tolerate a relatively wide range of temperatures. It has been noted to survive under a layer of ice during winter. The water is alkaline
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
.
This species is the only surviving member of genus Empetrichthys, the other, the Ash Meadows killifish
Ash Meadows killifish
The Ash Meadows killifish was first documented by Gilbert and historically occupied numerous springs near Ash Meadows, Nye County, Nevada...
(Empetrichthys merriami), having become extinct in the 1940s. There were three subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of E. latos, two of which are extinct today. Each occurred in a different spring
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
in the Pahrump Valley. The Raycraft Ranch springfish
Raycraft Ranch killifish
The Raycraft Ranch killifish or Raycraft poolfish, Empetrichthys latos concavus, was first described in 1948. It is extinct....
(E. latos concavus) became extinct when its spring was destroyed in the 1950s. The Pahrump Ranch killifish (E. latos pahrump) disappeared when its spring was pumped dry in 1958. The remaining fish was known as E. latos latos, a name which has lost its meaning since it became the only surviving subspecies. It is now known simply as the Pahrump poolfish.
In 1975 the Pahrump poolfish was extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
from its habitat, Manse Spring, when it experienced competition
Competition (biology)
Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource used by both is required. Competition both within and between species is an important topic in ecology, especially community ecology...
from the introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
goldfish
Goldfish
The goldfish is a freshwater fish in the family Cyprinidae of order Cypriniformes. It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium fish....
, some vegetation was removed, and the spring dried up due to groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
pumping nearby. On noting its impending extinction, scientists and officials removed specimens of the fish and transplanted them into three pools in different locations in Nevada. When the official recovery plan for the species was published by the United States Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
in 1980, it aimed to manage and protect the three transplanted populations. The fish has not been returned to its native habitat at Manse Spring because the area is under development and the water supply is not reliable.
Though the fish reproduced successfully and appeared to thrive in its new pools, it faced a number of challenges there. Flooding destroyed one of the pools, vandalism
Vandalism
Vandalism is the behaviour attributed originally to the Vandals, by the Romans, in respect of culture: ruthless destruction or spoiling of anything beautiful or venerable...
killed specimens at another, and the unauthorized introduction of mosquitofish
Mosquitofish
The mosquitofish is a species of freshwater fish, also commonly, if ambiguously, known by its generic name, gambusia. It is sometimes called the western mosquitofish, to distinguish it from the eastern mosquitofish . It is a member of the family Poeciliidae of order Cyprinodontiformes...
and crawfish further threatened the fish. Some fish were transplanted into a reservoir
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...
to replace the flooded population, but the USFWS had to intervene when Nevada State Parks officials planned to dredge the pond. Today the populations remain, but the habitat must be artificially maintained at times. As of 2004 only one population is stable. Threats still exist from groundwater pumping, vandalism, and introduced species. The USFWS still considers the species to be "in imminent danger of extinction" and is maintaining its endangered status.
External links
- Empetrichthys latos. The Nature Conservancy.
- Sweet, P. Endangered fish swim in water Las Vegas wants. Las Vegas SunLas Vegas SunThe Las Vegas Sun is a Pulitzer Prize-winning newspaper. It is one of Las Vegas, Nevada's two daily newspapers. It is owned by the Greenspun family and is affiliated with Greenspun Media Group....
November 18, 2008.