FWS Focus

Overview

Characteristics
Overview

Ozark cavefish are small, blind fish that appear pink and white due to a lack of pigment, revealing their inner organs. They were listed as threatened in 1984 under the Endangered Species Act. Primary threats to the species are water contamination and depletion of the groundwater from farming, mining and urban development.

Scientific Name

Amblyopsis rosae
Common Name
Ozark cavefish
FWS Category
Fishes
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The head of Ozark cavefish are dorsoventrally flattened, with a slightly protruding lower jaw. The fish have no pelvic fins. The dorsal and anal fins are located more posterior than usual. The caudal fin is rounded and has two to three rows of sensory papillae on the upper and lower halves. The literature provides conflicting information on maximum length, but individuals of up to 65 millimeters were documented in surveys conducted at Logan Cave.

Color & Pattern

Ozark cavefish lack melanophores, a type of pigment cell that produces and stores melanin. As a result, these fish appear pinkish-white due to the visibility of their internal organs.

Weight
Characteristic category

Habitat

Characteristics
Habitat

Cavefish occur in groundwater habitats like the Springfield Plateau Aquifer, within Boone and Burlington Formation limestones. They also live in cave streams with chert rubble substrate, wells and sinkholes, and occasionally, in the soil phreatic zone.

Cave or Karst

A natural chamber or series of chambers in the earth or in the side of a hill or cliff. An irregular limestone region with sinkholes, underground streams and caverns.

Characteristic category

Food

Characteristics
Food

Cavefish diets are not well understood, but are believed to include small crayfish, isopods, copepods, ostracods, larval salamanders and young of their own.

Characteristic category

Life Cycle

Characteristics
Reproduction

Geography

Characteristics
Range

Ozark cavefish distribution is restricted to the Springfield Plateau geologic province of Arkansas, Missouri and Oklahoma. The Springfield Plateau encompasses approximately 21,000 square kilometers and drains the White, Neosho and Osage rivers. There have been 83 confirmed Ozark cavefish sites, plus at least 37 unconfirmed sites. However, between 1990 and 2019 Ozark cavefish were only detected at 41 sites in Arkansas, Missouri and Oklahoma. The 41 sites are distributed throughout 10 counties including Benton County in Arkansas; Greene, Jasper, Lawrence, Newton, Christian, Barry and Stone counties in Missouri; and Delaware and Ottawa Counties in Oklahoma. Arkansas has eight caves. Missouri has 25 caves and wells, and Oklahoma has eight caves. In addition, an eleventh site was confirmed at an upwelling in Washington County, Arkansas in 2020.

Geography

The Ozark Cavefish is a small 2-1/4 inch long, blind, pinkish-white fish. Due to the dark environments in which it resides, sight is unnecessary and the cavefish has no eyes.

Ozark Cavefish distribution is restricted to the Springfield plateau geologic province of Arkansas, Missouri, and Oklahoma. Ozark Cavefish historically occurred at approximately 52 sites (Brown and Todd, 1987). Graening et al. (2010) reported 83 confirmed sites, plus at least 37 unconfirmed sites. There are an estimated 41 active Ozark Cavefish caves and wells in Arkansas, Missouri, and Oklahoma.

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Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

8 Items

Listing

Listing

Listing

Listing

Correction

Listing

Five Year Review

Five Year Review

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Listing

Dec 30, 1982

Dec 30, 1982 Listing
Review of Vertebrate Wildlife for Listing as End. or Thr. Species
  • Publication type: CNOR
Item 1

Listing

Feb 15, 1983

Feb 15, 1983 Listing (Substantial)
Findings on Certain Petitions and Reviews of Status for Several Species; 48 FR 6752-6753
  • Publication type: 90 day petition finding
Item 2

Listing

Jan 20, 1984

Jan 20, 1984 Listing (Warranted But Precluded)
Findings on Pending Petitions & Description of Progress on Listing Actions; 49 FR 2485-2488
  • Publication type: 12m petition finding
Item 3

Listing

Jan 31, 1984

Jan 31, 1984 Listing (Threatened)
Proposed Thr. Status for Ozark Cavefish; 49 FR 3889-3891
  • Publication type: Proposed
Item 4

Correction

Feb 16, 1984

Feb 16, 1984 Correction
(Correction) Findings on Pending Petitions & Description of Progress on Listing Actions; 49 FR 5…
  • Publication type: Notice
Item 5

Listing

Nov 1, 1984

Nov 1, 1984 Listing (Threatened)
Determination of Thr. Status for Ozark Cavefish (Amblyopsis rosae); 49 FR 43965-43969
  • Publication type: Final
Item 6

Five Year Review

Sep 8, 2006

Sep 8, 2006 Five Year Review (Information Solicitation)
Endangered and Threatened Wildlife and Plants; 5-Year Review of 14 Southeastern Species
  • Publication type: Notice
Item 7

Five Year Review

Jun 30, 2017

Jun 30, 2017 Five Year Review (Information Solicitation)
5-Year Status Reviews of 22 Southeastern Species
  • Publication type: Notice
Item 8