Horta

The Horta were a silicon-based lifeform native to Janus VI and members of the United Federation of Planets.

Biology
The Hortas' preferred habitat was amongst the rock of a planet, though they could survive in a typical atmosphere they found it disconcertingly empty to the touch.

The exterior of a Horta consisted of a rocky carapace which was highly resistant to damage; anything but the highest phaser settings felt like nothing more than a mild irritation to the Horta. On their underside Horta had numerous cilia which they moved about on. The Horta diet consisted of minerals which they dissolved with a powerful orange acid they secreted from glands all over their bodies, this acid was also the means by which Horta could tunnel through their rocky environment as easy as a humanoid might walk through air. When Horta were afraid they would lose control of their acid glands and squirt the powerful corrosive all around them.

Horta sensory organs included the ability to quite specifically detect the chemical composition of materials around them so they could target the most desired minerals. This form of sensory input dominated the Hortas perception of the world, being able to tell what gases made up the air that surrounded them and identifying species by the chemical composition of their blood.

Horta could survive exposure to the vacuum of space, though the shock resulted in a temporary coma. Horta could also happily eat through power conduits, quite unaffected by energies and radiation passing through them. They were equally invulnerable to shields, being able to easily pass through them. 

Reproduction
The Horta were extremely long lived, had no natural predators and were practically indestructible, as a result, over time, Horta populations grew substantially. As a means of population control, once every 50,000 years the Horta underwent a mass self induced extinction; The renewal.

Before each renewal the Horta laid their eggs in the Vault of Tomorrow and left a single caretaker, the Prime Mother, to see the next generation into the world.

The Horta also laid eggs between renewals, breeding like any other species. 

Maturation
New born Horta's would burn out of their eggs as a fleshy red wormlike creatures, about half a meter long. They quickly developed their rocky armour as they grew. Young Horta's acid was not as strong as that of adults.

Young Horta begin to eat as soon as they are born and quickly grow, reaching adult sizes in a matter of days. 

Culture
Horta history was recorded on the Stone of Memory.

The renewal was a major element of Horta culture, the Prime Mother of each new renewal was a significant figure in each generation of Horta and the young hoped to achieve the privilege of becoming the next Prime Mother at the next renewal.

The Horta were not capable of speech, they had no mouth, but could communicate by producing rumbling sounds. For ease of communication with humanoids Horta could be fitted with universal translators. Horta were also taught to communicate by etching text into the ground should their translator malfunction. 

History
Some time prior to the 23rd century, the Borg visited Janus VI; fortunately they did not recognize the Horta as any sort of lifeform and left without attempting assimilation. In the 23rd century the Horta entered into a renewal. Whilst Janus VI appeared uninhabited, the Federation established a mining colony, which the Prime Mother tolerated until 2267. In that year, the miners opened new levels of the mines and damaged eggs in the Vault of Tomorrow. The Prime Mother tried to protect the eggs and killed fifty of the miners, who were not aware of the damage they had done. The mysterious deaths resulted in the USS Enterprise (NCC-1701) being sent to investigate. Captain James T. Kirk and his first officer Spock conducted first contact with the Horta, Spock communicating via mind meld, and learned why the creature had attacked the miners. 

After the misunderstanding was resolved, the remaining Horta eggs hatched, and the species began to thrive once more. By 2300, there were nearly 1,100 new Horta on Janus VI, and fifty years later, there were more than 3,000. The Horta and Humans worked together on the mining operation, which became one of the most productive and profitable operations in the known galaxy, sourcing raw ore and rare elements to the entire Federation. (SS ST (Mother's Day); )

The Horta-Human mining alliance soon spread to other planets: the first planet found suitable for mining and the dietary requirements of the Horta was Lythos Prime. The operation on Lythos quickly gained a reputation for always meeting its quotas on time. 

Naraht, one of the first Horta hatched, went on to join Starfleet. 

In 2305, the Horta Sanaht began representing Janus VI on the Federation Council. 

One of the Dax symbiont's hosts was involved in operations working with Hortas to mine planetary cores. 

In 2369, the Horta-Human operation on Lythos Prime was attacked by a Borg cube whose sensors had mistakenly detected a carbon-silicon hybrid species on the planet, kelbonite deposits giving false readings of the Humans and Hortas. After realizing their error, the Borg attempted to assimilate the Horta, but were unable to as the Horta dissolved the drone's injection tubules on contact. Effectively resisted, the Borg retreated. 

In 2370, the Horta-manned starship USS Darwin, commanded by Captain Dalen, assisted the USS Enterprise (NCC-1701-D) in exploring the dyson sphere the latter vessel had discovered the previous year. Also in that year, the Horta Ttan and her family (at the time a clutch of eggs) were recruited to assist in rebuilding Bajor's mining industry, which had been devastated in the Occupation. Unfortunately as the ship transporting the Horta family approached Deep Space 9, it was ambushed by a Cardassian vessel, and Ttan was kidnapped. Ttan was rescued shortly after, but returned to find her children hatched, but no home on Bajor as the Council on Ecological Controls refused to let the Horta settle. Instead Ttan and her family were permitted to take up residence on Bajor's moon The Prodigal where they found many valuable mineral deposits. 

In 2371, Captain Jean-Luc Picard, Spock, and Dr. Lewis Zimmerman attended a ceremony on Janus VI in which Tetsua, the mother of the next generation of Horta, was installed. (SS TOS (Tears for Eternity))

In 2376, the USS da Vinci aided in stopping a Horta plague on Janus IV. 

In 2379, the Horta Chwolkk became an engineer on the USS Titan. 

In 52,267, Tetsua witnessed the hatching of the next generation of Horta. (SS TOS (Tears for Eternity))

Alternate timelines
In an alternate timeline, the Horta became the guardians of the Guardian of Forever in 2464. (SS ST (Guardians))