Okay, in The Next Generation episode 'The Host' Dr. Crusher falls in love with a Trill named Odan. At some point in the episode Odan and Riker are in a shuttlecraft and get attacked by an unknown ship. Odan insists that he can't be beamed down to the surface, and we later learn that Trills are a combined species (host and symbiont) and that using the transporter would kill the symbiont. Alright. As we all know, Jadzia Dax is a Trill....but!!! We see her use both Cardassian and Federation transporter technology. So......what gives??? Trills can't use transporters in one series, and then can in another. Anyone care to explain???
The Trill symbionts were a secret at the time of 'The Host.' The implication is that Odan is afraid that the biofilter is going to take a look at Odan, the symbiont, and try and remove it because it's a foreign body in the host. Once they're aware of it, all it takes is a memo to all the engineers in Starfleet, and, by extension, the Federation and all the races they know, that says 'hey, when you're transporting Trill, the transporters are going to register this parasitic life form in their belly, disregard that notice, it's supposed to be there, don't try and filter it out.'
DS9 season 1 begins in 1993, which is season 6 of TNG. 'The Host' takes place on Star Date 44821.3, and DS9 episode 1 takes place on 46379.1. So, we're talking about roughly two years difference. Jadzia Dax joined Starfleet Academy somewhere between Star Dates 36000 and 36999. Years before 'The Host' takes place. Yet, you're implying that Starfleet doesn't know about Trills? Impossible!
Well, first of all, Jadzia wasn't joined to Dax until 2367, which was from Stardate 44000 and 44999. Second, I'm going directly off of what's established in The Host, which is that Crusher and her medical staff initially treat the symbiont Odan as a parasitic infection of the humanoid host until he corrects them. A lot of what comes later about the Trill doesn't gel completely with their presentation in The Host - there, the host's personality is completely overwhelmed by the symbiont's and the humanoid has those ridges, rather than spots. The Host pretty much has to be taken in very broad strokes in the greater context of the Star Trek mythos.
...then there's the whole matter of Sisko knowing Curzon was a Trill waaaay back when. And that's just Sisko. Starfleet and the Federation at large must have known about Trills for many many years before "The Host". Start yer backpedaling...
Again, The Host has to be taken in very broad strokes, which includes the secret of the symbionts. But the secretive nature of the Trill is established as something of the proverbial hat for the Trill - remember their issues with Joran and how like 90% of the population can be joined, but the official line is that only a very small portion can. A secret of this nature, though, inevitably gets revealed to individuals, who can be trusted. It's just that the more people know, the less of a secret that secret is. The situation in The Host was just pretty much the final straw, since it was so public.
Curzon was Sisko's mentor, its possible Sisko was trusted with that was then the secret of Trill society, since Curzon didn't seem to hold any thing about bein' a Trill sacred like the rest of the culture. Obviously the Federation was aware of Trills as an alien species, but it is possible they didn't know about the symbionts such a small percentage of the population carried. And don't forget, the aliens in TNG 'The Host' thought that Odan was the son of the man who negotiated the original treaty between them, not the newest host. It wouldn't be that difficult to explain the name issue from generation to generation, dependin' on how long contact was maintained.
I think the simplest explanation is that the Federation had contact with the Trills from way back. They don't make it a big deal about how they are a joined species (as Odan said, do Humans make a big deal about how they are a single being?), so while many people know about the Trill, not many of them realise they are a joined species. And since not all Trill are joined anyway, this could explain why knowledge about joining is even rarer. As to why beaming would kill Odan, well, it's because he'd only recently been joined, and the biochemical connections were still being created. Going through a pattern buffer could disturb them, and since they hadn't had enough time to become as resilient as we see Jadzia, that is why beaming could kill him.
It's possible that the transporter would have had absolutely no ill effect upon Odan. But Odan was simply scared to death of traveling through a transporter. A more extreme case of what we saw with people like McCoy, Pulaski and Barkley. .
That is a continuity error, plain and simple. Trek has legion of them, both across serieses, and movies, and within any single series. The explanation is that the writers either didn't know what themselves or other writers had written earlier, or did they know but just didn't care and chose to disregard it.
Thank you all for your responses. Obviously it's just bad writing. And thank you to whomever mentioned Curzon. The man that negotiated the Khitomer Accords(The peace treaty between the Klingons and the Federation). Curzon was a Starfleet Officer and a Federation Ambassador, as well as Benjamin Sisko's mentor. And you're telling me, that not once did he come across a situation where he'd have to use a transporter? Impossible! And if you're implying that Curzon and Sisko "kept it a secret", try again. We're talking about Starfleet here. Think of all the medical check-ups and physicals one has to go through as a member of Starfleet. It'd be impossible to continuously avoid those matters. If something had happened to Curzon (after all there was an assassination attempt at the Khitomer Accords during The Undiscovered Country) Starfleet would have to know his anatomy, including the worm he carries inside his stomach. Everyone knew Curzon, and knew he was a "joined" species.
I disagree that everyone had to know Trills were joined just because of Curzon. Obviously his species name would be common knowledge, just not this particular detail. As for the transporter: I find it more likely that Odan was just being a wimp and hated transporters personally, just like McCoy. AFAIK, all information in "The Host" regarding Trill biology came from Odan himself, so the only reason they thought Trills could never transport was because Odan said so. Curzon probably used transporters all the time. And there are probably various degrees of personality strength among hosts. Some, like Kareel, were rather meek and were easily overwhelmed by the symbionts. Others had more independence and could find a balance with their personality and the symbiont's. As for the ridges: Non-canon though it may be, I accept the Forged In Fire explanation: Spoiler: novel It was the Klingons. A strain of the Augment virus managed to infect a Trill colony when the Klingons visited it.
I don't think Curzon had anything to do with Starfleet, least of all being employed by that military organization. Starfleet just provided the negotiator with a young bodyguard/liaison/bellhop named Ben Sisko. The two would then go on to "serve together" on a starship at least once, but with only one of them being on Starfleet employ. (Really, was Curzon an ambassador, either? Or was he just a freelance negotiator like Riva from "Loud as a Whisper"? Which episode would establish his credentials?) Whether Curzon ever told Sisko that something was bugging him is unknown. The fact that Dax didn't die when Curzon did might have come as a surprise and a shock to Sisko, but he would have had a bit of time before DS9 "Emissary" to get used to the fact that his best friend was a parasite. As for Curzon not getting caught - such an important VIP would never be short on ways to avoid scrutiny! He could tell his personal aide and friend to operate the transporter for him every time, and Sisko would neatly disable the biofilter (in case this was a threat to the symbiont's health or life) or the recording function of the scanners (in case Curzon and Odan merely worried about leaving a trace, and there never was a threat to their life from transporter use). If anything, it's a case of excellent writing, as nothing about DS9 really directly contradicts what was said or shown in TNG, even though DS9 writers give us a far more dramatically useful character and species. Timo Saloniemi
I kind of think it's funny how we have such a hard time accepting that it was just the writers way of working themselves out of a corner. They created a species, the Trill, with this cool host/symbiont thing and they want to reuse the idea. When they originally screen tested Terry they had her in the TNG Trill makeup but decided it took too much away from her face and Decided to come up with the spots instead. They also probably realized that the whole can't use a transporter thing wouldn't work so they decided to ignore it, figuring that the average viewer wouldn't notice that detail. I think the idea that the Feds didn't know about the symbionts is silly. Trill (the DS9 version) is a member of the Federation. No way they could hide something like that during the admission process. There is even reference made to McCoy from TOS dating Emony Dax.
Holy fanwanking Batman! And yes, it was established that Curzon was the Federation Ambassador to the Klingon Empire. Jadzia herself said that Curzon negotiated the Khitomer accords. And Ben wasn't his bellboy. Curzon was his mentor in his academy days, when Curzon was old and no longer in active duty-hence the title Old Man.
That's a bit dismissive... I'd say that at least half of Trek is left open to discussion, not because it's bad writing, but because it's unneccesary in terms of the story... Take Voyager...in S7 of TNG we're told that all starships are now limited to a speed of warp 5, except in emergencies. TNG references this episode a couple of times, Voyager never mentions this. This rising nacelle effect is commonly understood to somehow negate the damaging effect warp travel has (it might even be Word of God) but it's never mentioned in the series - because it's unnecessary! It's the same with the Trill, for my part I would assume that the fact the Trill were a joined species is an open secret...probably if you'd asked everyone on the crew, in the end you would have found someone who said "oh yeah, I'd heard that some Trill have parasites in their stomachs" but, it's not like it's every Trill! And even if it was, consider this - there are over 150 distinct species in the Federation! Without going on Wikipedia, name 150 countries in the UN! Then give a detailed breakdown of the history of each of those countries! And all the people living in those countries are human! The transporter thing, Beverly says it would "damage the symbiote" if they were to transport it...Beverly has been wrong before! I would guess that Odan was pulling a McCoy on her, and she looked at her tricorder readings and took what he'd said and given that she was distracted at the time she just assumed this was true. Think about it, we've seen the transporter used to beam The Doctor from place to place, that is far more far-fetched than beaming a symbiote and host!