Start Date
14-2-2013 1:00 PM
Description
Cave species exhibit a suite of dramatic differences in comparison to their surface living relatives, commonly referred to as troglomorphy (Christiansen 2005). One hallmark feature of troglomorphy is the severe reduction or complete loss of eyes and functional vision. The two most abundant cave beetle species in Mammoth cave, the 2-3 mm small carrion beetle Ptomaphagus hirtus (Packard 1888; Peck 1973; Peck 1975; Tellkampf 1844) and the 6-8 mm long predatory ground beetle Neaphaenops tellkampfii are good examples of this (Barr 1979). P. hirtus tends to hide in crevices and usually goes unnoted to the regular visitor of Mammoth cave. N. tellkampfii by contrast is very active and therefore noticed by most attentive visitors of Mammoth cave as the fast moving insect crossing their path. Neither of these two beetles possesses compound eyes typical for diurnal insects (Barr 1962). In N. tellkampfii, external eyes as well as the related regions in the brain are completely absent (Ghaffar et al. 1984). Compound eyes are also missing in P. hirtus. However, small lens structures can be noted in the lateral head (Figure 1). P. hirtus is also fl ghtless because of the complete reduction of the hind wings (Peck 1973). In his comprehensive study of North American cave animals, Alpheus Spring Packard (1888) studied the anatomy of the lens-like structures in P. hirtus. He concluded that P. hirtus was blind based on his failure to find an optic nerve connecting from cells underneath the lens structure to the brain.
Recommended Citation
Friedrich, Markus; Chen, Rui; Buschbeck, Elke K.; and Peck, Stewart, "A Functional Visual System in the Cave Beetle Ptomaphagus hirtus" (2013). Mammoth Cave Research Symposia. 10.
https://digitalcommons.wku.edu/mc_reserch_symp/10th_Research_Symposium_2013/Day_one/10
Included in
Animal Sciences Commons, Forest Sciences Commons, Geology Commons, Hydrology Commons, Other Earth Sciences Commons, Plant Sciences Commons
A Functional Visual System in the Cave Beetle Ptomaphagus hirtus
Cave species exhibit a suite of dramatic differences in comparison to their surface living relatives, commonly referred to as troglomorphy (Christiansen 2005). One hallmark feature of troglomorphy is the severe reduction or complete loss of eyes and functional vision. The two most abundant cave beetle species in Mammoth cave, the 2-3 mm small carrion beetle Ptomaphagus hirtus (Packard 1888; Peck 1973; Peck 1975; Tellkampf 1844) and the 6-8 mm long predatory ground beetle Neaphaenops tellkampfii are good examples of this (Barr 1979). P. hirtus tends to hide in crevices and usually goes unnoted to the regular visitor of Mammoth cave. N. tellkampfii by contrast is very active and therefore noticed by most attentive visitors of Mammoth cave as the fast moving insect crossing their path. Neither of these two beetles possesses compound eyes typical for diurnal insects (Barr 1962). In N. tellkampfii, external eyes as well as the related regions in the brain are completely absent (Ghaffar et al. 1984). Compound eyes are also missing in P. hirtus. However, small lens structures can be noted in the lateral head (Figure 1). P. hirtus is also fl ghtless because of the complete reduction of the hind wings (Peck 1973). In his comprehensive study of North American cave animals, Alpheus Spring Packard (1888) studied the anatomy of the lens-like structures in P. hirtus. He concluded that P. hirtus was blind based on his failure to find an optic nerve connecting from cells underneath the lens structure to the brain.