Cooks’ cave millipede (Pseudotremia cookorum)

Cooks' cave millipede, Pseudotremia cookorum
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Cooks’ cave millipede fact file

Cooks’ cave millipede description

PhylumArthropoda (1)
GenusPseudotremia (2)

Cooks’ cave millipede is named in honour of William and Gayle Cook, the owners of Little Mouth Cave, where this species was discovered during surveys between 1995 and 1998 (2) (5). Possessing the typical millipede form, the body of Cooks’ cave millipede is composed of numerous hard, ring-like segments. Each segment bears two pairs of legs, with the exception of the first and last segments, which are legless, and the second, third and fourth segments, which only possess a single pair (6). Like many subterranean animals (7), the body of Cooks’ cave millipede appears to be unpigmented, although when magnified, its segments possess a light greyish-purple sheen, with a white glossy area in-between (2). The eyes of Cooks’ cave millipede are composed of 15 to 17 simple, light-detecting lenses called ocelli. These are grouped into five or six irregular rows, forming a darkened, roughly triangular region on each side of the head, just above the antennae (2) (6).

Male length: 19 mm (2)
Female length: 23 mm (2)

Cooks’ cave millipede biology

As a recent discovery, relatively little is currently known about the biology of Cooks’ cave millipede. Nevertheless, like most millipedes, this species probably feeds on detritus, which is likely to have been deposited by underground streams or by rainwater that has drained from the surface. Living in the darkness, Cooks’ cave millipede has little use for vision, and instead relies on its antennae, which not only help this species to feel objects, but also detect chemical signals in its environment (8).

Millipede reproduction involves the male transferring sperm to the female using specially modified legs called gonopods, after which, the female lays numerous eggs. The eggs hatch into a legless, pupoid stage, which then moults into a more developed form called the first “stadium” which has legs, but no ocelli. With each subsequent moult, the young millipede grows larger, gaining additional segments, legs and ocelli (8).


Cooks’ cave millipede range

Cooks’ cave millipede is only found in southern Indiana, U.S.A., where it is restricted to a small number of caves, which lie in the south-western region of the Mitchell Plain in Harrison County (2).


Cooks’ cave millipede habitat

A cave-dwelling species, Cooks’ cave millipede may be found on bare flowstone or on mudbanks bordering subterranean streams (2).


Cooks’ cave millipede status

This species has not yet been classified by the IUCN Red List (3); however it is classified as Critically Imperiled (G1) by NatureServe (4).


Cooks’ cave millipede threats

While there are no known threats to Cooks’ cave millipede at present, it has a highly restricted range and its overall population is likely to be relatively small (4). Consequently, a small-scale adverse event could potentially lead to this species’ extinction.


Cooks’ cave millipede conservation

The discovery of this rare species was made possible by a three year survey, initiated by The Nature Conservancy in Indiana, of all wildlife found within caves in the Blue River basin of southern Indiana (5). The Nature Conservancy of Indiana is now working to ensure that the important sites within this region are properly managed to preserve the unique wildlife that they support (5) (9).


Find out more

To learn more about conservation efforts in southern Indiana visit:



This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:


Sheet-like deposits of limestone formed where water flows over the surface of the floor and walls of a cave.
In invertebrates, referring to stages of growth, whereby the hard outer layer of the body (the exoskeleton) is shed and the body becomes larger.


  1. ITIS (April, 2009)
  2. Lewis, J.J. (2000) Five new species of Pseudotremia from caves in the Blue River area of southern Indiana (Diplopoda: Chordeumatida: Cleidogonidae). Myriapodologica, 6: 55 - 68.
  3. IUCN Red List (April, 2009)
  4. NatureServe Explorer (April, 2009)
  5. Lewis, J.J., Pursell, F.A. and Nelson, M. (1999) A Tale of Two Cities: Conservation Focused Cave Bioinventories by The Nature Conservancy in the Karst Areas of Louisville and Saint Louis. 1999 National Cave and Karst Management Symposium, 0: 115 - 118.
  6. Barnes, R.S.K., Calow, P., Olive, P.J.W., Golding, D.W. and Spicer, J.I. (2001) The Invertebrates: A Synthesis, 3rd Edition. Blackwell Science, Oxford.
  7. Marshall Cavendish Corporation. (2001) Endangered Wildlife and Plants of the World. Marshall Cavendish Corporation, New York.
  8. O'Toole, C. (2002) The New Encyclopedia of Insects and their Allies. Oxford University Press, Oxford.
  9. The Nature Conservancy in Indiana (April, 2009)

Image credit

Cooks' cave millipede, Pseudotremia cookorum  
Cooks' cave millipede, Pseudotremia cookorum

© Dr Julian J. Lewis

Dr Julian J. Lewis
Lewis & Associates LLC
Cave Karst & Groundwater
Biological Consulting
17903 State Road 60
United States of America
Tel: +1 (812) 967 7592


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