Spring cavefish

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Spring cavefish
Forbesichthys agassizii.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Percopsiformes
Family: Amblyopsidae
Genus: Forbesichthys
D. S. Jordan, 1929
Species:
F. agassizii
Binomial name
Forbesichthys agassizii
(Putnam, 1872)
Synonyms

Chologaster agassiziiPutnam, 1872

The spring cavefish (Forbesichthys agassizii) is the only member of the genus Forbesichthys and is one of seven species in the family Amblyopsidae. This species is listed as state endangered in Missouri, but it is considered to be of least concern by the IUCN Red List due to its relatively large population size and number of subpopulations. The spring cavefish inhabits caves, springs, spring runs, and spring seeps. It is subterranean, emerging at dusk and retreating underground an hour or two before dawn. The species is located within areas of the central and southeastern United States. It stays underground after dawn, but then emerges into surface waters at dusk. They are a carnivorous fish and are well adapted to their environment. The species' breeding behavior is rarely documented. Spawning occurs underground and in darkness between January and April. The status and distribution of cave-obligate species is incomplete or lacking entirely, which makes conservation and management decisions difficult. Kentucky and Missouri are the two main states that have their agencies managing this species in some way.

Contents

Geographic distribution

Originally found in a deep well in Lebanon, Tennessee, the spring cavefish is distributed within the central and southeastern United States. [2] It inhabits select springs, spring runs/seeps, and caves from central and western Kentucky, west towards the Tennessee River, to south central Tennessee. It also is located in areas west across southern Illinois to southeastern Missouri. [3]

The spring cavefish's distribution has decreased from within its original streams and springs. This species is affected by the activities on the surface of the ground. Any activity that reduces water quality or quantity affects the spring cavefish. It is vulnerable to pollution from many different sources. Some of these sources include nearby agricultural fields, pastures, septic tanks, sewage lagoons, urban runoff, mines, and livestock waste. [4] Some of the springs fluctuate drastically in flow and turbidity as a result of direct connections with surface drainage or they were enclosed as water supplies or otherwise modified by man. [5]

Ecology

Spring cavefish stay underground after dawn, but then emerge into surface waters at dusk. They are dark brown dorsally and fade to a creamy brown towards the pelvis and reach a maximum length of 3.5 in (8.9 cm). The head is sloped, and it has a protruding lower jaw. The fish has no pelvic fin or adipose fin. Its dorsal fin is set further back compared to most fish. [6] This species is susceptible to developing retinoblastomas. [7]

The spring cavefish is well adapted to its environment, as it has a well-developed sensory system. This system occurs in clusters on the head. Most fish detect food by sight, taste, touch, or smell, or by a combination of these senses. Sight is important in the detection of food by most species, but this is presumably excluded with the slightly blind spring cavefish. They use their underdeveloped eyes to distinguish between light and darkness. However, spring cavefish cannot readily distinguish between edible and inedible substances by touch alone, but once in contact with the lips, the sense of taste enables the fish to distinguish among these items. [2]

Another hurdle for this species is food is often lacking in their habitats, so they compensate for this scarcity of food with cannibalistic behavior. Cannibalism in the spring cavefish presumably serves two purposes: it enables the adults to survive in an environment where food is the principal limiting factor, and it serves as a means of population control. [2] The spring cavefish can be considered its own predator, because of the cannibalism behavior and the lack of natural predators within the caves. However, they eat a wide range of insects, small crustaceans, smaller fish, and some detritus. [8]

Cave environments provide a relatively stable habitat in terms of temperature fluctuations. However, the different species living in caves are reliant on food being brought to them by underground streams. This makes spring cavefish highly vulnerable to external factors as subterranean aquifers are becoming increasingly tapped for irrigation purposes, and many sites may be at risk from drying out either temporarily or permanently. [8]

Life history

The breeding behavior of spring cavefish is sparsely documented. Spawning occurs underground and in darkness between January and April. Spring cavefish are oviparous; however, the eggs are carried in gill chambers of the females. Females produce roughly 100 young per female. [9] The average spring cavefish lives for about three years and typically reaches a length of about 1.8 to 2.6 inches (4.6 to 6.6 cm). [4]

Conservation

The status and distribution of cave-obligate species is incomplete or lacking entirely, which makes conservation and management decisions difficult. [8] This species is listed as endangered in Missouri. The IUCN Red List considers the spring cavefish to be of least concern due to its relatively large population size and number of subpopulations. This species is declining, but many of the reasons are unknown. The Kentucky Department of Fish and Wildlife Resources is proposing to investigate the status, distribution, ecology, phylogenetic relationships, and threats to populations of three cave-associated fishes in the family Amblyopsidae in Kentucky. Kentucky and Missouri are the two main states with agencies managing this species in some way. Missouri has purchased Cape LaCroix Bluffs Conservation Area to provide habitat for the state endangered spring cavefish. This 63.21-acre area supports natural wetlands, limestone bluffs, and beech mesophytic forests unique to eastern Missouri. [4]

Related Research Articles

The northern cavefish or northern blindfish is found in caves through Kentucky and southern Indiana. It is under review for possible listing under the Endangered Species Act of 1973 in the United States as of 2023, and the IUCN lists the species as near threatened.

The Percopsiformes are a small order of ray-finned fishes, comprising the trout-perch and its allies. It contains just ten extant species, grouped into seven genera and three families. Five of these genera are monotypic.

<span class="mw-page-title-main">Amblyopsidae</span> Family of fishes

The Amblyopsidae are a fish family commonly referred to as cavefish, blindfish, or swampfish. They are small freshwater fish found in the dark environments of caves, springs and swamps in the eastern half of the United States. Like other troglobites, most amblyopsids exhibit adaptations to these dark environments, including the lack of functional eyes and the absence of pigmentation. More than 200 species of cavefishes are known, but only six of these are in the family Amblyopsidae. One of these, Forbesichthys agassizii, spends time both underground and aboveground. A seventh species in this family, Chologaster cornuta, is not a cave-dweller but lives in aboveground swamps.

<span class="mw-page-title-main">Ozark cavefish</span> Species of fish

The Ozark cavefish, Amblyopsis rosae, is a small subterranean freshwater fish endemic to the United States. It has been listed as a threatened species in the US since 1984; the IUCN currently lists the species as Near Threatened, though it was previously listed as Vulnerable between 1986 and 1996. It is listed as Endangered and Threatened by the Missouri Department of Conservation.

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<span class="mw-page-title-main">Alabama cavefish</span> Species of fish

The Alabama cavefish is a critically endangered species of amblyopsid cavefish found only in underground pools in Key Cave, located in northwestern Alabama, United States in the Key Cave National Wildlife Refuge. It was discovered underneath a colony of gray bats in 1967 by researchers Robert A. Kuehne and John E. Cooper and scientifically described in 1974.

A blind fish is a fish without functional eyes. Most blind fish species are found in dark habitats such as the deep ocean, deep river channels and underground.

<span class="mw-page-title-main">Blind cave eel</span> Species of fish

The blind cave eel is a species of cavefish in the family Synbranchidae. It is the longest cavefish in Australia and one of the only three vertebrates in Australia that is restricted to underground waters, the other being the blind gudgeon and the Barrow cave gudgeon. It is blind, its body is eel-like and elongated, and it has a non-pigmented skin with colours ranging from white to pink.

The juil ciego or blindwhiskered catfish is a species of three-barbeled catfish endemic to Mexico. This species is troglobitic, inhabiting a certain stream that flows through a single cave system.

<i>Typhlichthys subterraneus</i> Species of fish

Typhlichthys subterraneus, the southern cavefish, is a species of cavefish in the family Amblyopsidae endemic to karst regions of the eastern United States.

<span class="mw-page-title-main">Cavefish</span> Fish adapted to life in caves

Cavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, troglomorphic fish, troglobitic fish, stygobitic fish, phreatic fish and hypogean fish.

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<span class="mw-page-title-main">Spotted sucker</span> Species of fish

The spotted sucker is a species of sucker (fish) that is native to eastern North America. The spotted sucker inhabits deep pools of small to medium rivers over clay, sand or gravel. They are occasionally found in creeks and large rivers. Through its life stages, the spotted sucker goes from a mid-depth predator to a bottom forager. Spotted suckers have a lifespan of approximately six years and spawn in April and May. Limited knowledge of the occurrence, abundance, and natural history of this species has been an impediment to status assessment and the determination of need for conservation measures within this family.

<span class="mw-page-title-main">Silverjaw minnow</span> Species of fish

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<span class="mw-page-title-main">Northern studfish</span> Species of fish

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<span class="mw-page-title-main">Orangefin darter</span> Species of fish

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<span class="mw-page-title-main">Swamp darter</span> Species of fish

The swamp darter is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is endemic to the Eastern United States.

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<i>Amblyopsis</i> Genus of fishes

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<span class="mw-page-title-main">Hoosier cavefish</span> Species of fish

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References

  1. NatureServe (2013). "Forbesichthys agassizii". IUCN Red List of Threatened Species . 2013: e.T202611A18230637. doi: 10.2305/IUCN.UK.2013-1.RLTS.T202611A18230637.en . Retrieved 20 November 2021.
  2. 1 2 3 Hill, L.G. 1969. Feeding and Food Habits of the Spring Cavefish, Chologaster agassizi. American Midland Naturalist:83:110-116.
  3. Page, L.M. and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 pp.
  4. 1 2 3 Missouri Department of Conservation. 2000. Policy Coordination Section.
  5. Poly, W.J., and C.E. Boucher. 1996. Nontroglobitic Fishes in Caves: Their Abnormalities, Ecological Classification and Importance. American Midland Naturalist: 136:187-198.
  6. Woods, L.P., and R.F. Inger. 1957. The Cave, Spring, and Swamp Fishes of the Family Amblyopsidae of Central and Eastern United States. American Midland Naturalist 58:232-256.
  7. Fournie, J.W., and R.M. Overstreet. 1985. Retinoblastoma in the spring cavefish, Chologaster agassizi. Putnam. Journal of Fish Diseases:8:377–381
  8. 1 2 3 Science Encyclopedia. 2011. Cave-Fish. Science Encyclopedia 1290 pp.
  9. Etnier, D.A., and W.E. Starnes. 1993. The fishes of Tennessee. University of Tennessee Press, Knoxville, Tennessee. 681 pp.