The asari, native to the planet Thessia, are often considered the most influential and respected sentient species in the galaxy, and are known for their elegance, diplomacy, and biotic aptitude. This is partly due to the fact that the asari were among the earliest races to achieve interstellar flight after the Protheans, and the first to discover and settle the Citadel.
A mono-gender race, the asari are distinctly feminine in appearance and possess maternal instincts. Their unique physiology, expressed in a millennium-long lifespan and the ability to reproduce with a partner of any gender or species, gives them a conservative yet convivial attitude toward other races. Favoring compromise and cooperation over conflict, the asari were instrumental in proposing and founding the Citadel Council and have been at the heart of galactic society ever since.
Asari resemble humans in terms of basic skeletal structure with five digits on each hand and feet that are relatively straight (certainly in comparison to species like quarians and turians). This similarity allows asari to wear human armor. A typical asari has a blue to purple complexion, though a teal complexion is possible albeit seemingly rare. Some asari, such as Matriarch Lidanya, Matriarch Benezia, Liara T'Soni, and Tela Vasir have facial markings, which are unique colored patterns that vary for every asari. Some of these facial markings resemble the eyebrows that humans have, but the asari do not think of the markings as such themselves. In the place of head hair, asari possess semi-flexible, cartilage-based scalp-crests that grow into shape. These structures are rigid, and do not "flop around" as some believe. Asari have navels as well as breasts that continue to grow with age. Asari also have a robust cellular regenerative system; while they do not heal faster than other species, they are known to reach over 1000 years of age. This long lifespan is rivaled only by the krogan. Asari can see ultraviolet at the short-wavelength end of the spectrum. Asari blood is purple.
There is some conflicting information regarding the gender of the asari. Asari are a mono-gendered species with no concept of gender differences. According to Liara, "male and female have no real meaning for us," and, if asked, says that she is "not precisely a woman." At the same time, asari are often referred to as if they are an all-female race. To humans at least, asari appear female with feminine physical characteristics and voices. Even among the asari, many individual asari are referred to as “she” and “her“ but some asari prefer male pronouns, while others gravitate toward gender-neutral where language allows. Asari also bear feminine titles like “huntress” and “matriarch” and asari offspring are referred to as “daughters“; however, the asari may have chosen feminine pronouns to simplify language translations, or the terms themselves are simply the result of imperfect translation, deliberate or otherwise. However asari gender is defined, they are innately different from humans, for asari can mate and successfully reproduce with any other gender or species through a form of parthenogenesis. Although they have one gender, they are not asexual and do in fact require a partner to reproduce. However, asari reproduction is very different from other forms of sexual reproduction. An asari provides two copies of her own genes to her offspring, one of which is passed on unaltered. The second set of genes is altered in a unique process called melding, also known as the joining or the union. During melding, the eyes of the asari initiating the meld dilate as she consciously attunes her nervous system to her partner's, sending and receiving electrical impulses directly through the skin, however physical contact is not strictly necessary. A common phrase used before melding is "embrace eternity," presumably to help focus the partner's mind. Effectively, the asari and her partner briefly become one unified nervous system, sharing memories, thoughts, and feelings. The offspring is always an asari, regardless of the species or sex of the "father" and in the case that the offspring is of two asari, the father is the one who does not give birth.
Uniquely, the asari are known to be perceived as attractive to many other species. This may be because of shared physical characteristics (e.g., body shape for humans, skin color for salarians, head fringe for turians).
Additionally, pairings with krogan are not affected by the Genophage. As such, pairings with asari are sometimes seen as a way for a krogan to circumvent the Genophage and have children of their own.
The drawback to the asari means of reproduction are the Ardat-Yakshi. These individuals possess a rare genetic defect that causes an asari to overwhelm and destroy her partner’s nervous system when joining. The condition seems to appear only amongst pureblood asari, those whose parents are both asari.
It is also possible for an asari to meld with another for the sole purpose of transferring thoughts, without reproduction. The asari initiating the meld can both send and receive information. Liara melds with Commander Shepard several times for the purpose of viewing and helping understand the visions Shepard received from the Prothean beacon. Shiala later melds minds with Shepard for the purpose of “uploading” the Cipher into Shepard’s mind in order to help the Commander understand the visions. Liara also states that the melding of minds is a sign of a deep connection between two individuals, something often reserved for friends and family members; it is also a way to say “farewell.”
It is not clear whether ability to meld minds is present from birth or whether asari undergo some sort of puberty to gain it and, if so, when this occurs. When she first melds minds with Shepard, Liara is 106, quite young for an asari. By the time she is 42, Falere’s Ardat-Yakshi condition had already come to light indicating she had attempted to meld at least once. Morinth’s condition was also discovered by the time she was in her 40s.
Asari pass through three climacteric life stages, marked by biochemical and physiological changes:
The Maiden stage begins at puberty and is marked by the drive to explore and experience. Most young asari are curious and restless, and it is not uncommon for many to try their hand at dancing in bars or working as mercenaries during this time.
The Matron stage of life begins around the age of 350, though it can be triggered earlier if the individual melds frequently. This period is marked by a desire to settle in one area and raise children.
The Matriarch stage begins around 700 years of age, or earlier if the individual melds rarely. Matriarchs become active in their community as sages and councilors, dispensing wisdom from centuries of experience. Their knowledge and guidance may be one reason why Matriarchs are rarely seen outside asari space.
However, it should be noted that each stage can be started whenever an asari feels that she has reached the correct level of maturity. While each stage of life is marked by strong biological tendencies, individuals do make unexpected life choices. For example, there are Maidens who stay close to home rather than explore, Matrons who would rather work than build a family, and Matriarchs who have no interest in community affairs.
When the Protheans departed, they left a single beacon on Thessia, around which the asari later built a lavish temple devoted to Athame. This beacon contained Vendetta, a Prothean VI, and over the following centuries was the source of countless technological advances that allowed the asari to eventually become the most powerful race in the galaxy. The beacon's existence became a closely-held state secret, as its revelation would have discredited the virtually universal belief that the asari attained such heights on their own merit. By 2183 CE, few outside the highest echelons of the asari government were aware of the part the Protheans played in asari history.
Because of their long lifespan, asari tend to have a "long view" not common in other races. When they encounter a new species or situation, the asari are more comfortable with an extended period of passive observation and study than immediate action. They are unfazed that some of their investments or decisions may not pay off for decades or centuries. Matriarchs can seem to make incomprehensible decisions, but their insight is evident when their carefully-laid plans come to fruition. In interstellar relations, this long view manifests in the unspoken policy of centrism. The asari instinctively seek to maintain stable balances of economic, political, and military power. Traditionally, asari spread their influence through cultural domination and intellectual superiority. They invite new species of advanced development to join the galactic community, knowing that their ideals and beliefs will inevitably influence the existing culture. The asari tend toward communal, consensus attitudes among themselves too: for example, they prefer to live in shared spaces aboard starships even if there are alternatives available.
Asari believe that their offspring acquire the best qualities of the "father" from the melded genes, but evidence is anecdotal. They frown upon intraspecies conception.