Kartchner Caverns Microbial Observatory
National Science Foundation
photo of caverns



Impact of Tourism on Kartchner

Nonculture-Based Analysis

Culture-Based Analysis




Nematode-bacteria associations are one of the most common associations occurring in nearly every environment on the planet.  Poorly studied environments, such as those considered extreme, like hot springs, deserts, tundra and caves remain a rich reservoir of biodiversity.  In this study, three habitats were sampled; mud and guano along the Big Room trail and a soil sample taken above the Cave. 

Collected nematodes were first identified by trophic group by examining morphology of the buccal structures.  All collected isolates were considered to be in the bacteriovore trophic level.  Nematodes were cultured on baby food agar (Stock, 2001).  Differential interference microscopy was used to achieve a “rough” identification.  For identification to the species level, analysis of the 18S rRNA gene was performed. 


Based on morphological characteristics, we determined that there were two distinct species in Kartchner; one isolated from mud samples, and another from guano samples.  Both isolates belong to the genus Rhabditis Maupas (Nematoda: Thabditdae) (Figures 1 and 2).


Figure 1. 

A Rhabditis sp. isolated from guano that was collected from Kartchner Caverns.  A. Female; B. Male; C. Anterior region of female; D. Female showing eggs in uterus; E. Male tail, lateral view; F. Male spicule, lateral view.  (Photos courtesy undergraduate Brody C. Holohan)

Nematode Figure 1


Figure 2. 

A Rhabditis sp isolated from a Kartchner Caverns mud sample.  A. Female; B. Male anterior end; C. Male tail, lateral view; D. Female uterus showing egg; E. Female tail, lateral view.  (Photos courtesy undergraduate Brody C. Holohan)

Nematodes Figure 2


The sample from soil above the Cave represents a member of the genus Acrobeloides (Family Cephalobidae) (Figure 3).  Thus, the nematodes within Kartchner are different from those recovered outside Kartchner.

Figure 3. 

An Acrobeloides sp. isolated from the soil above Kartchner Caverns.  A. Tail of adult female; B,C. Anterior end of female showing lip region and complete esophagus; D. Intestine showing bacteria inside (arrow).  (Photos courtesy undergraduate Brody C. Holohan)

Nematode Figure 3


updated 7/2009

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