http://static.comicvine.com/uploads/original/11114/111144184/3957022-3533775806-potpo.jpg
From birth, through life, and until death, the survival of a species depends on the ability of the individual member to survive on a daily basis. In turn, their ability to survive often depends upon the often unique defense mechanisms that they have evolved. All species, regardless of their position on the food chain, have methods in place to protect themselves from potential dangers. Below are details on the defense mechanisms displayed in the horned lizard, mantis shrimp and the exploding ant.
Horned Lizard
Phrynosoma taurus are just one of the many species of horned lizard with the capability to shoot blood from their eyes. When the lizard feels threatened by a much bigger enemy, like a dog or coyote, they will reduce blood flow out of the head to build up pressure all over the lizard's face. At a certain point, the blood pressure will build up so much in the eye that it will cause the vessels to burst which then allows the blood to shoot out at a rapid speed three to five feet away from the lizard. The lizard has the ability to control when the blood shoots out but can also shift their eye muscles the control the direction that the blood will shoot as well. So, there are no special sacs in the eye that store this blood for later use, but an adaption of body regulation that is considered a canine and feline repellent when excreted due to the toxicity in the blood. This is what makes the lizard stand out among others in the animal kingdom. |
Peacock Mantis Shrimp
Stomatopoda: Odontodactylus scyllarus had a very unique defense mechanism that stores a lot of energy as elastic energy waiting to be released. This energy is stored in a ball-joint or spring like mechanism. When the energy is released, the spearer or smasher raptorial appendages eject at high speeds. The strike lasts 5-10ms. The raptorial appendages contain 4 muscles in the merus, these include two extensors and two flexors. The muscles are actually specialized for slow contractions. These extensor muscles have a twitch time of 400 ms, and reach maximum tetanic tension in 700 ms (Burrows & Hoyle). The first form of force generation is the appendages direct impact. When the mantis shrimp is ready for defense the process begins by two slow and one fast motor axons being fired throughout the muscle. Overshooting spike will occur in each muscle fiber from the first activation. Smaller extensors receive a fast axon which may give rise to a second overshooting, but these muscles will only be weakly excitable. In order for the muscle to recover it will take several seconds until the muscle will respond again. The second is the cavitational bubble that is initiated by the striking of the appendage (please see peacock mantis shrimp tab). Both adaptations produce a lethal weapon in which the mantis shrimp is able to defend itself against other predators in the sea. |
Malaysian Exploding Ant
Camponotus saundersi has evolved to create an adhesive and toxic secretion composed primarily of hydrocarbons, polyacetates and alcohols. Additionally, this mixture is corrosive when it comes in contact with other living tissues. Along with the defensive elements present in the compound are pheromones that are used to signal other ants to potential danger. This compound mixture is manufactured in the extremely enlarged mandibular gland of the ant and is stored there for potential use in the future as well. The secretion of the toxic adhesive from the mandibular gland is not stimulated unless the ant is in danger as the release of the compound is lethal to the ant. |