Excation Biology

Excation, like all species on Kalem, share some traits with earth life. However it is foolish to assume that they have any real similarities to us, as thier biology has evolved in an entirly different way than that of humans. [[File:Excation internals by goldsmartie-dacvrme.jpg|thumb|293x293px|1. Upper vascular pathway 2. central air bladder

3. hearts (paired)

4. stomach

5. stomach spine

6. female gonads (paired)

7. womb

8. male gonads (paired)

9. penis

10. liver/kidneys (paired)

11. reproductive canal

12. reproductive slit ]]

Physiology
Externally, an Excation is about four and a half feet tall to the crown of their head, though this shortness is mostly due to posture as attempting to imitate a more strait backed and stiff legged pose, akin to humans, has shown them as being around five and a half feet tall.

They have a blunt-ended snout, with a mouth containing twelve sharp teeth that flows into their two large rhomboid ear-like structures, which serve as gas exchange organs. Their lower mandibles are not attached to each other at the centre to form a single lower jaw, allowing them to move separately, with another jaw set far back into their gape. They have large yellow eyes with twin pupils, allowing for a larger range of focused vision

They have a shape that is similar to a humanoid biped shape, but becomes more unusual if you look at the specifics. Their limbs are quite long in most cases, but genetic and environmental effects can alter the relative proportions. They have a peculiar spine, which is formed of many vertebra, attached to the exoskeleton and each other to form three stiff rods, normally held so there is a noticeable angle between the second and third rod, which is a normal relaxed state. The hip bones seem to protrude quite far, but this is in fact the exoskeleton forming the shape, behind which sits twin filtration organs.

The excation tail is a long organ used to for grip, social signalling and the storage of fat. It is made of multiple exoskeletal segments that are each quite small, alowing for a more articulate and dexterous limb.

They have three fingers on each hand, which tapers into a short claw. They also have two toes, which are equally short and have an underside covered in long hairs for stability on the sand. There are exposed, muscular joints in places like the elbow and knee, as well as the face, these joints are covered by a soft and stretchy skin which also sits between all joins in the exoskeleton.

Their hair is short and extremely soft, with each hair branching at the base into multiple more hairs. They have a mane of longer and more bristly hair that starts at the top of the head and ends at the end of the second spinal shaft, and is often styled. The tip of the tail also has a large brush of the more corse hair. The Excation body is built almost like a space suit, with an outer exoskeleton, combined with a number of valves in the openings, such as ears and throat, and a shield-like covering over the eyes. The net  result of these adaptations is that the Excation is environmentally sealed, which keeps fluids in and dust out. The adaptation has also made them effective at colonising the space around them, as they never had to develop space suits beyond simple heat and light regulation.

Digestive system
Most of the Excation's chest is filled with a highly efficient digestive system, while their lower body contains respiratory organs and a heart analogue. The respiratory organs store oxygen for when the primary gas exchange organs, the Excation's large ear like structures, cannot be used due to situations like sandstorms. The Excation's periodically replace the air, every one to two hours, and it is considered very rude to draw attention to the fact they are doing it.

The exaction digestive system is extremely efficient but still quite simple. It consists entirely of a stomach, with no intestines, and only one opening, the mouth. The stomach itself can expand in size quite readily, able to push down into the lower body should it be required. The stomach contains numerous short, sharp spines, which secrete acids and enzymes.

Circulatory System
The species has a double circulatory system, seen in many related species. In the cavity between the exoskeleton and the organs there circulates a slightly yellow, but mostly clear heamolymph, called 'outer blood'. There is a secondary vascular system that circulates around the organs and through the bones. This is referred to most often as 'inner blood'. The basic solvent of the excation's bodily fluids is a strong alcohol that readily vaporises, giving them the oder of vodka or other strong spirits.

A peculiarity of excation blood is that instead of producing scabs, they have a protein system that turn it into neurotoxin on contact with the air. The exact mechanism and reason is still unknown, but it has been hypothesised as a defensive mechanism to put predators off from attacking another member of the species, as any injury bad enough to puncture the excation resilient exoskeleton is likely to be fatal, so the neurotoxin makes the best of a bad situation through a form of altruism.

Senses
Excation vision is a combination of red and infra red, with a tiny amount of ultraviolet. This suits them perfectly well on their home planet where the light is filtered by the atmosphere, but can cause problems in other environments. Most excation who live off-world have adapted space goggles to allow them to see more easily in brighter environments.

Hearing is a quite basic affair, seeming no stronger than a humans, though able to hear higher pitches, at the expense of lower ones. The large ear like structures do not capture any sound, instead hearing happens in the patches of skin that litter the excations body, meaning that sound is felt rather than heard.

Reproduction
Excation are sequential hermaphrodites, with two functional reproductive systems, one male and one female, with hormonal activity changing which of the excation's reproductive structures are active. Excation couples even have synced reproductive cycles, meaning that one will be male while the other is female and vis-versa.

Mating procedures are highly organised, with the egg being taken by the local government and looked after until it hatches, whereupon it will be looked after by individuals and couples that have the capability to do so.

This practice appears to a cultural adaptation of an instinctive behaviour, as similar egg pooling is seen in a fair few of the excation's closest relatives. Its believed the process makes the entire previous generation protective of its young, as there is no way of telling whose offspring is whose. The cultural implications is also that the excation concept of parent and teacher are identical, biology having little to no impact on who they see as important figures in their life. The same is true for siblings, as Excation parents often adopt unrelated children to raise together.

Children
Excation childen are better considered Hatchlings or Nymphs, or even possibly Nymphlings. Hatching without legs, Nymphlings do not gain their full adult body structure until their fifth instar, which is at an age of about 10 months or equivilent to a 5 year old human child.

Mutations
Exaction biology is extremely susceptible to mutations, known as Makol in easkun, and while most mutations are harmless to the species, their physiology being resistant to the changes wrought by the mutation. The kinds of mutations are usually the doubling of features of the excation, such as ears, tails, forearms and eyes.