Lycosa tarantula
From Memory Alpha, the free Star Trek reference
Lycosa tarantula is the scientific name for a species of spider that originates from Spain on Earth. Some have been known to be kept as pets. At some point, a number of tarantulas of this type were taken to the planet Titus IV.
Miles O'Brien kept a tarantula named "Christina" as a pet in the early 2360s while he served aboard the Enterprise. Though Chief O'Brien was once afraid of spiders, he took her in as a pet after almost stepping on her on Titus IV. He once showed Christina to Lieutenant Barclay, who wasn't particularly fond of it. (TNG: "Realm of Fear")
- The spider shown in the episode is not in fact a Lycosa tarantula, but a Brachypelma smithi, a species of true tarantula from Mexico. Lycosas are wolf spiders, and not actually tarantulas. Tarantulas fall into the family Theraphosidae.
- It should be noted that Christina was never seen, nor mentioned during the entire run of Star Trek: Deep Space Nine or any other time than "Realm of Fear" on Star Trek: The Next Generation.
