Iroshan

The Iroshans were a society that lived in the Iroshar system, consisting primarily of the Irosha and zhr species. Small groups of other species, particularly Ferengi, also lived in the Iroshar system and were sometimes considered Iroshan as well. The term "Iroshar" on its own was generally taken to refer to Iroshar III, the most popular planet in the Iroshar system.

The Irosha were a humanoid species, similar to and visually indistinguishable from Humans.

The zhrs were a small, insect-like species. Zhrs were typically between six and fourteen centimeters in length. They were capable of flight and speech, and were able to learn Human languages. On some parts of Iroshar, capitalizing the first letter in the word "zhr" as a proper noun was considered offensive.

Symbiosis
Zhrs could live independently or form a symbiotic relationship with a host organism, in which the symbiont was converted to a non-material form and stored in the host's brain. Because of this, zhrs were believed to descend, at least in part, from a species native to another dimension.

In a symbiotic relationship, the host would generally be aware of the symbiont's presence; usually, this meant that the host could see and/or hear the symbiont, even though it was not physically present.

Zhrs could naturally join with animal host species native to Iroshar IV. To join with an Irosha or another species required special equipment; however, this was commonplace on Iroshar. Either the host or the symbiont could choose to break the link at any time, which would cause the symbiont to rematerialize.