The fish is ulcerating because its water is foul. The Basic rules for keeping fish are. :- 1 inch of fish needs at least 1 gallon of water.:- Every fish tank needs a permanently running cycled filter. :'- Every fish tank needs to have at least 50% of its water changed every week. Fail in any of the above and I can guarantee you will always have sick or sickening fish. Observe the basics and you and your fish stand a chance of success.
Carp is more spot fishing they can be found at a range of depths. During Spawning they will be in the shallows around the mouth of rivers and streams. Use corn or full worms.
spot fish mostly eat shrimp and other small fish
With a guppy you need to look at the gravid spot. This is a dark spot in the fish's belly. A large gravid spot indicates the fish is likely to be pregnant. You can tell how pregnant the fish is by how large the spot is. Sorry I have no experience with other species.
The sore on your mouth might be as a result of a bacterial infection.
== == anything aggressive
It means you have a spotted fish...CONGRADULATIONS
It is a "Gravid Spot". Yes it indicates pregnacy.
it uses there eye sight to spot them
A gravid spot is the dark area on the fish's butt.
by their mouth
No. In runescape, there are lots of places you can fish swordfish.
they eat coral