Shivering, Lock Lips, Jerk Vibrate Tails:
* Shivering: This is a common sign of excitement or anticipation in Oscar fish. It could be related to feeding, play, or even the start of a mating ritual.
* Lock Lips: This is a dominant display in Oscars, often seen during territorial disputes or as part of a courtship ritual. The fish will press their mouths together and may push or shove each other.
* Jerk Vibrate Tails: This is usually a sign of aggression or territoriality. They may be trying to assert dominance or warn off another fish.
Fighting vs. Mating:
It's tricky to definitively say if your Oscars are fighting or mating based solely on these behaviors. However, here are some clues to help you differentiate:
Fighting:
* Aggressive Posture: Fins will be spread out, bodies angled toward each other.
* Flaring Gills: They will puff out their gills, making themselves appear larger.
* Biting or Nipping: They may actually bite or nip at each other.
* Chasing: One fish may chase the other around the tank.
Mating:
* Courtship Displays: These include "lock lips" as you mentioned, but also circling, tail-twitching, and even the male leading the female to a nest site.
* Egg Laying: If you see the female laying eggs in a chosen spot, it's a sure sign of mating.
* Less Aggression: While there might be some chasing, it's less aggressive than a territorial fight.
What to Do:
* Observe Carefully: Pay close attention to the context of the behavior. Are they near a nest site? Are they fighting over food?
* Water Changes: Make sure the water quality is good, as stress can exacerbate aggression.
* Plenty of Space: Ensure your Oscars have enough space to roam. If they are in a small tank, they may feel more territorial.
* Provide Hiding Spots: This helps them feel secure and can reduce aggression.
* Separate if Necessary: If you see prolonged, aggressive behavior, consider separating the fish for a time.
Remember: Even during mating rituals, Oscars can be aggressive. Keep a close eye on them, and if you're concerned, consult a knowledgeable fish expert.