Erisians look human. But they aren't.
Some of their more obvious differences:
Their eyes have a rather unique function - They change color depending on their moods. More noticeably then in humans.
For example, Brown eyes will go black if angry or amber if happy and laughing. Blue eyes will go Icy blue when angry, almost silver, and can go a deep sea blue if happy.
Human doctors have determined that this is a form of Heterochromia. Erisians just consider it normal.
Their blood is more purple in tone than red, and they are limited to 3 different blood types
These types are:
T-A - Members of the Lalor family have this blood type. It is the most dominant blood type.
T-B
T-O
Most Erirsians are left handed. Those who are right handed are rare and considered defective in the dark ages, now in the more modern era, they are just considered different.
Pregnancy gestation is 8 months. Not nine. Hard to say if mating with non Erisians will shorten or increase this timeline.
Erisian Females bodies become infertile for a period of 12 months after the birth of a child. This has been discovered by scientists as a biological defence against over population.
Not so obvious differences:
The Erisian Immune system works a lot like a human's but they are more resilient to common human ailments - like colds and flues. However they have a high number of cases of Xenopolycythemia with 1 in 50 adults being diagnosed with the illness. Since their contact with the federation, this illness has become non fatal.
The Erisian pulse is strongest beneath their collar bone.
Their Hearts have a small fifth chamber, which has no actual use in the current evolution of the race, but it is still there in the current day Erisians.
Their ears look like human ears, but every once in a while, a child is born with ears which are pointed but curve backwards. These children are considered genetic throwbacks to one of two ancestral races that they say the modern day Erisians come from.
They do not have Appendix nor do they have Tonsils. Their race evolved without them.
Also, Adult Erisians do not get Wisdom teeth.
There has been no known cases of Albinos in Erisian history.
Erisians have 28 bones in their feet - two additional bones that brace between the Metatarsals of the last two toes.
Erisians also have 2 less ribs than humans.