In both AP Bio and 10 Bio, we’ve been discussing the fundamentals of life, which include a lot of chemistry.
But we’ll take a brief hiatus from the chemical context of life, to discuss an actual living being that benefits from water’s properties. This organism is the Caribbean Manatee:
Notice the pattern of distribution. What can you say in regards to this? What properties of water account for this distribution?
The antillean manatee (Trichechus manatus) is distributed in the green area, Puerto Rico included. These organisms are threatened by our own industrial exploits. Habitat depletion, water sport injuries, niche disruption, irresponsible tourism, hunting, illegal poaching… The lives of these gentle herbivores, mistaken for sirens during the early days of European colonization and conquest, have been tragic.
They look sad, innocent, almost saint-like. But we should not pity them. In fact, this elephant-like sea mammal is quite amazing:
“Manatees have sensitive tactile hairs that cover their bodies and face called vibrissae. Each individual hair is a vibrissal apparatus known as a follicle-sinus complex (FSC). Vibrissae are blood filled sinuses bound by a dense connective tissue capsule with sensitive nerve endings that provides haptic feedback to the manatee.
Usually vibrissae are found on the facial regions of terrestrial and non-sirenian aquatic animals and are called whiskers. Manatees, however, have vibrissae all over their body. The vibrissae located in their facial region are roughly 30 times denser than the vibrissae on the rest of their body. Their mouth consists of very mobile prehensile lips which are used for grasping food and objects. The vibrissae on these lips are turned outward during grasping and are used in locating vegetation. Their oral disk also contains vibrissae which have been classified as bristle-like hairs (BLH) that are used in non-grasping investigation of objects and food.
Research has found that manatee vibrissae are so sensitive that they are able to perform active touch discrimination of textures. Manatees also use their vibrissae to navigate the turbid waterways of their environment. Research has indicated that they are able to use these vibrissae to detect hydrodynamic stimuli in the same way that fish use their lateral line system.”
These haptic abilities—‘haptic’ means ‘touch’—provide manatees with almost superhero-like abilities to sense danger and food sources. They play the role of a ruminant in Caribbean waters, which means that they store lot of fat, they are slow, and their diets consist of plants (Thalassia, mangrove leaves, algae, etc.)