Adaptations of an Arthropod Colwyn Sleep

This ancient species is long since extinct, however its descendants have changed over time into a new species with specialized adaptations that make it more suitable to survival in it’s marine environment. Let’s take a look at a few…

1. Chitin Shell

Selective evolution has changed this ancient organism over time into a new species, a member of the phylum arthropoda. Like all anthropoids, this species has developed a hardened shell made of chitin. This shell has proved effective against selective pressure against predators by protecting the species during an attack. It also serves to provide protection of internal organs. It also allows for the attachment sites of muscles allowing movement using appendages. The disadvantages of this species exoskeleton is that it cannot grow and must be shed annually leaving the organism vulnerable to attack. 2. Cephalization and Nervous System

Like other anthropoids, this species has cephalization, a nervous system with a true brain and ventral nerve chord, along with highly specialized sense organs. The head has five pairs of appendages. Two pairs of these are antennae and the other three are mouthparts. These are specialized for sensory perception and feeding. The mouthparts are lined with long sensory hairs for tasting and are armed with razor-sharp teeth for gripping and tearing off bits of food. Over time this species developed both compound eyes and simple eyes. The simple eyes are like ours, one lens focuses incoming light. The compound eyes work differently as light is focused with many smaller lenses. The compound eye works well for detecting movement and is useful for avoiding predators and capturing prey. The cephalization in combination with increased sensory perception has proved a selective advantage for survival of the species.

3. Mobility

This species is of the class Crustacea and like many crustaceans it is a marine animal. Over time it’s body shape changed and elongated to permit the development of appendages which allow it to move easily in it’s marine environment. Along it’s thorax are four pairs of jointed legs (each with tiny pinchers) for walking. It’s abdomen is equipped with swimmerettes, small paddle-like structures that assist in movement and reproduction. This crustacean also has a tail and uses it’s uropod and telson to quickly swim backward. These adaptations for movement have proved successful in this species’ environment. It is able to crawl along the sea floor with it’s walking legs, swim to new locations with it’s swimmerets, and escape prey using its tail. 4. Claws

Located near the front of the abdomen, this species also has developed appendages in the form of a pair of large claws. These claws are used for both eating and defence. It is impossible for this species to pass food to its mouthparts using these claws due to their position and bulk. Instead,it uses them to capture and disable the prey that makes up its diet. Once the prey have been seized or crushed by the major claws, the tiny pinchers on the walking legs pick apart the food.The smaller legs then pass morsels of flesh to the mouthparts. It holds it’s food in place with it’s legs and tears off shreds by gripping the meat with it’s teeth located on the mouthparts and jerking it’s head backwards. This has proved a useful adaptation for both obtaining food, and defence against predators.

5. Respiratory and Circulatory Systems

This species has an open circulatory system. It uses gills located above its legs for respiration underwater. At its gills, hemocyanin picks up oxygen molecules to be used by the body. It’s heart pumps this blood through a blood vessel to a hemocoel, an open space surrounding the organs. This open circulatory system has proved a selective advantage in that it is not sensitive to pressure changes. This allows this species to survive at greater depths allowing it to escape predators that cannot dive as deep. It has also permitted this species to colonize over a more diverse habitat. It’s open circulatory system allows it to exist in shallow tide pools, as well as deep within the ocean. Change over time… The original species changed significantly over time by developing adaptations which make it more suitable to survival in its marine environment