Trichechus Manatee Case Study

Trichechus manatus lattirostris or the Florida manatee is a subspecies of the West Indian manatee (Trichechus manatus) (Bauer et al., 2012; Marshall and Huth, 1998). Manatees are herbivores and spend several hours consuming different vegetation (Marshall and Huth, 1998). This is quite impressive as Florida manatees have poor acuity and often live in murky waters (Gaspard et al., 2013; Bauer et al., 2012; Reep et al., 2002). Vibrissae or tactile hairs present on the entire body may allow them to differentiate vegetation (Marshall and Huth, 1998). Tactile hairs possess innervated blood filled sinuses that transmits an automatic feedback from their environment (Gaspard et al., 2013; Reep et al., 2002). However cranial and post-cranial vibrissae

to test the tactile discrimination of textures by facial vibrissae in two blindfolded male Florida manatees (2012). Two acrylic plates with equal width and groove pattern were presented in a standard (2mm grove width) and comparison (4-2.03 mm grove width) stimuli (Bauer et al., 2012). The comparison or wider choice were the intended “correct” answer and were selected by pushing the plate into place (Bauer et al., 2012). The BLHs were used to initiate investigation and as the comparisons became more difficult the U2 fields were utilized (Bauer et al., 2012). The Weber fraction or discrimination threshold were 0.075 (2.15 mm) and 0.025 (2.05 mm) and were lower than that of the Phoca vitulina (0.09) showing comparatively Florida manatees have a higher discrimination of textures (Bauer et al., 2012). This may be dangerous in the wild as the manatees need to be close to objects to fully investigate resulting in entanglements and other dangerous

2013). A sinusoidally oscillating sphere was used between frequencies 5 to 150 Hz using a two-alternative forced study (Gaspard et al. 2013). If the stimuli were detected the manatee would press a paddle if not it would remain still (Gaspard et al. 2013). While establishing the tactogram lips were not flared concluding the BLHs were used to sense the hydrodynamic stimuli (Gaspard et al. 2013). Vibrissae were restricted with mesh of different sizes ranging from large (10%, 3.175 mm) to extra fine (100%, 0.035 mm) (Gaspard et al. 2013). The threshold increased as a greater number of vibrissae were restricted and no response from either subject were obtained at 25 Hz with the extra fine mesh (Gaspard et al. 2013). Sensitivity to the stimulus decreased with an increase in the restriction of vibrissae (Gaspard et al. 2013). Sensitivity to water movement may help the Florida manatees navigate and determine water currents (Gaspard et al.