wes_von_papineäu
Our Roving Correspondent
NEWS RELEASE
The Center for North American Herpetology
Lawrence, Kansas
*http://www.cnah.org
11 August 2008
PREDATOR-PREY INTERACTIONS BETWEEN HELLBENDERS (CRYPTOBRANCHUS
ALLEGANIENSIS ALLEGANIENSIS AND C. A. BISHOPI) AND NATIVE AND NONNATIVE FISHES
Brian G. Gall. 2008. Master's Thesis, Missouri State University, Springfield. viii + 84 pp.
ABSTRACT: The introduction of nonnative fishes often results in the local extinction of
native amphibians due to a lack of evolutionary history and therefore, minimally-adapted
antipredator behaviors toward the introduced fishes. Populations of Hellbenders
(Cryptobranchus alleganiensis) in Missouri have declined considerably since the 1980?s,
coinciding with a rapid increase in trout introductions for recreational angling. I examined
Hellbender and fish predator-prey interactions by: (1) examining the foraging behavior of
predatory fishes in response to a Hellbender secretion; (2) comparing the number of
secretion and control-soaked food pellets consumed by trout; and (3) comparing the
response of larval Hellbenders to chemical stimuli from introduced (trout) and native fish
predators. Brown Trout, Walleye and large Banded Sculpin respond to Hellbender
secretions with increased activity while small Banded Sculpin responded by decreasing
activity. In addition, Brown Trout ingested more Hellbender secretion-soaked food pellets
than control pellets, while Rainbow Trout expelled secretion-soaked food pellets. Finally,
larval Hellbenders exhibited weak fright behavior in response to chemical stimuli from
nonnative trout relative to their responses to native predatory fish stimuli. These
combinations of responses indicate that predation by nonnative fishes may be a plausible
hypothesis for the decline of Hellbender populations in Missouri.
*****
A gratis PDF of this thesis is available from the CNAH PDF Library at
*http://www.cnah.org/cnah_pdf.asp
The Center for North American Herpetology
Lawrence, Kansas
*http://www.cnah.org
11 August 2008
PREDATOR-PREY INTERACTIONS BETWEEN HELLBENDERS (CRYPTOBRANCHUS
ALLEGANIENSIS ALLEGANIENSIS AND C. A. BISHOPI) AND NATIVE AND NONNATIVE FISHES
Brian G. Gall. 2008. Master's Thesis, Missouri State University, Springfield. viii + 84 pp.
ABSTRACT: The introduction of nonnative fishes often results in the local extinction of
native amphibians due to a lack of evolutionary history and therefore, minimally-adapted
antipredator behaviors toward the introduced fishes. Populations of Hellbenders
(Cryptobranchus alleganiensis) in Missouri have declined considerably since the 1980?s,
coinciding with a rapid increase in trout introductions for recreational angling. I examined
Hellbender and fish predator-prey interactions by: (1) examining the foraging behavior of
predatory fishes in response to a Hellbender secretion; (2) comparing the number of
secretion and control-soaked food pellets consumed by trout; and (3) comparing the
response of larval Hellbenders to chemical stimuli from introduced (trout) and native fish
predators. Brown Trout, Walleye and large Banded Sculpin respond to Hellbender
secretions with increased activity while small Banded Sculpin responded by decreasing
activity. In addition, Brown Trout ingested more Hellbender secretion-soaked food pellets
than control pellets, while Rainbow Trout expelled secretion-soaked food pellets. Finally,
larval Hellbenders exhibited weak fright behavior in response to chemical stimuli from
nonnative trout relative to their responses to native predatory fish stimuli. These
combinations of responses indicate that predation by nonnative fishes may be a plausible
hypothesis for the decline of Hellbender populations in Missouri.
*****
A gratis PDF of this thesis is available from the CNAH PDF Library at
*http://www.cnah.org/cnah_pdf.asp
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