Chapter 1, The Reptilian Spectacle - UWSpace - University of ...

packages.
All statistical analyses were performed using the Systat 13 and Mystat 12 statistical software
2.2.5 Additional Observations
In addition to the main experiment, observations were made on spectacle blood flow in physically
restrained snakes (hand-held), in moulting snakes, and in geckos.
The first attempts to document spectacle blood flow were done whereby the snake’s head was
handheld while making observations with a slit-lamp or stereomicroscope. Although at the time, this
was merely an attempt to stabilize the animal’s head, in retrospect it’s understood that this will have
elicited a strong sympathetic response, so observations done under these conditions were reviewed in
this light.
Spectacle blood flow was observed and video-recorded in snakes that were were in the
renewal phase of their integument as judged by the opacification of the spectacle. Observations were
made on coachwhip snakes (M. flagellum) and corn snakes (Elaphe guttata). Unlike the situation in the
main experiment, moulting corn snakes tended to remain still within the experimental box long enough
to make observations. The experimental setup for observing the corn snakes was identical to that for
the coachwhip snakes including the transparent acrylic holding box, the NIR-modified slit-lamp and
camera, and an ambient temperature of 27ºC with approximately 290 lux of illumination. The only
difference in the case of a yearling individual was the size of the holding box being reduced to 2 cm x
2 cm x 15 cm (H x D x W). Based on the assumption that visual clarity would be poor due the clouded
spectacle, the effect on blood flow of a perceived threat was elicited either by physically touching the
snakes or by jostling their holding box.
Attempts were made to observe spectacle blood flow in coachwhips while food (frozen/thawed
mice) was presented. A juvenile mouse was held by 10 cm forceps and inserted into the holding box. In
no case did a snake attempt to feed, so this avenue was discontinued.
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