Trivia: This is the first episode where McCoy says, "He's dead, Jim."
Trivia: The designation on McCoy's stateroom is 3F 127.
When the salt creature goes to put its suction-like hands on Kirk, Kirk begins to scream before the creature even touches him, and continues to scream as the creature places its fingers on Kirk's face. However, all the other times that crewmen were killed on the planet, there were never any screams emitted. In fact, the only scream heard was from "Nancy" finding the corpse, which was within earshot of Kirk and McCoy.
Trivia: Truth serum is still used in the 23rd century.
After Darnell's death, why do Kirk and McCoy return to the planet with Sturgeon and Green, who are science and command officers respectively, not security officers.
Trivia: In a conversation with Uhura, Spock reveals that Vulcan has no moon.
When Kirk and Dr. Crater argue about Kirk's telling Crater and Nancy to stay on the Enterprise for safety reasons, shots behind Kirk show his arms are crossed. In shots from behind Crater, Kirk's arms are not crossed.
When Rand and Sulu find the dead man in the environmental suit, Sulu bends down towards him to check his pulse. As soon as Sulu's fingers touch the man's face, you see the supposedly dead man's eyes flinch.
When Rand brings Sulu the plate of food, it has a bowl of colored fruit cubes on it, and that is how it appears in most scenes. In the scene where Green wanders into the Botany lab and looks longingly at the salt shaker on the tray, a single close-up shot shows the bowl of cubes has transformed into a plate of cubes.
When they first arrive on the planet, the tricorder Kirk is holding for McCoy starts on his left shoulder, disappears in the next shot, then in the next shot after that reappears in his right hand.
Despite the fact that McCoy has a tricorder that can scan for life forms, Kirk orders him to return to the Enterprise to scan for life forms there.
Several times the communicators fail to chirp when someone activates them.
When McCoy tell Kirk that the dead crewman has no salt in his body, the blood pressure gauge was almost all the way up.
McCoy: The machine is capable of almost anything, but I'll still put my trust in a healthy set of tonsils.
Crater: The heroic captain and the intrepid doctor cross interstellar space to preserve our health! Oh, your sense of duty is overwhelming. Now, will you please go back where you came from and tell whoever issues your orders to leave me and my wife alone?!?
Uhura: Mr. Spock, sometimes I think if I hear that word "frequency" again, I'll cry.
Spock: It is illogical for a communications officer to resent the word "frequency."
Uhura: Then I'm an illogical woman. Why don't you tell me what an attractive lady I am? Or how your planet looks when the moon is full.
Spock: Vulcan has no moon, Miss Uhura.
Uhura: I'm not surprised.
Kirk: You bleed too much, Crater. You're too pure and noble. Are you saving the last of its kind... or has this become Crater's private heaven here? This thing becomes wife, lover, best friend, wise man, fool, idol, slave. It isn't bad to have everyone in the universe at your beck and call. You win all the arguments.
Uhura: Starship base requesting explanation of our delay, sir. Space Commander Dominguez says we have supplies he urgently needs.
Kirk: Tell Jose he'll get his chili peppers soon. They're prime Mexican reds. I handpicked them. But he won't die without them.
Kirk: He's all yours, Plum. (McCoy glares at him) Dr McCoy.
Kirk: He's not trying to kill us. He is trying to frighten us. And he is doing a pretty good job.
Kirk: How your lost love affects your vision, Doctor, doesn't interest me. I have lost a man. I want to know what killed him!
Kirk: (speaking to McCoy) You could learn something from Mr. Spock, Doctor. Stop thinking with your glands!
Kirk: We're all aware of the need for salt on a hot and arid planet like this, Professor, but it's a mystery, and I don't like mysteries. They give me a bellyache and I got a beauty right now.
Crater: Earth history, remember? Like the passenger pigeon or the buffalo ... once there were millions of them; prairies black with them. One herd covered three whole states. When they moved -- like thunder.
Kirk: It isn't a bad life to have everyone in the universe at your beck and call, and you win all the arguments.
Sulu: May the Great Bird of the Galaxy bless your planet.
Sulu uses the phrase "The Great Bird of the Galaxy." The term was a nickname for Star Trek creator and producer, Gene Roddenberry.
In the opening credits William Shatner and Leonard Nimoy's names appear without their usual 'Starring' and 'Also Starring' credits.
Sulu's plant (the one that he and Yeoman Rand debate about being male or female) is a hand-operated puppet. When its "petals" extend, it shapes just like the hand that's operating it.
Dr. Crater's weapon is a reuse of the Starfleet laser pistol from the first two Star Trek pilot episodes.
As Green walks around the Enterprise, at one point there is a rare appearance of a command division female officer wearing the standard skirt uniform with black pants. This occurs immediately after the first scene with Sulu and Rand in the Botany Lab. It's clearly the skirt top with black pants, as the collar is deeper, like the skirt uniforms, rather than the male shirts which have tight collars.
Crewman Darnell, played by the late Michael Zaslow of Guiding Light fame, is not, in fact, the first red shirt seen killed on Star Trek, because he wears a science blue uniform. Zaslow returns later in the second season as Ensign Jordan in "I, Mudd" and also has an uncredited role almost 30 years later as Eddie, the Town Barkeeper in the movie Star Trek: First Contact.
In the episode "The Squire of Gothos" the Salt Monster can be seen again as a statue in Trelane's collection.
This is the first time we learn that Lt. Uhura speaks Swahili from her encounter with the creature pretending to be a crewman.
The Botany Section was merely a redressing of the Sickbay.
This was the first time Kirk calls McCoy "Bones". Kirk did not use the nickname in the episodes that were originally scheduled to air before this one.
The real Enterprise model that was used in this epsiode currently resides in the Air and Space Museum in Washington, D.C.
This is the sixth episode of the original Star Trek series produced, yet NBC decided to choose it to open its first season.