if you look on the sides of your aquarium or on leaves of plants you would see a small transparent flat oval with small rows of dots inside of it; this is the egg case.
It depends on what species they are.
Many freshwater fish if not most lay their eggs on the side of the aquarium where it is slightly colder. The eggs live off of their embryo sac for two-three weeks after hatching, so keeping them colder while they are eggs slows down their metabolism allowing them to use less of their embryo sac. If not on the side of the aquarium freshwater fish will lay their eggs on the plants (either live or plastic) that is in the aquarium. In the wild most freshwater fish spawn in areas of heavy plant life to give them a place to hide when they are born and to eat off the plants till they are big enough to eat more meaty foods. For marine fish it all depends on their natural environment, many will only breed in the aquarium if the conditions are perfect. Drifting seaweed is a great place for many predatorial fish to lay their eggs. While fish that dwell in a reef generally like to find a small crevice to lay their eggs where other fish can't eat them. In a home aquarium marine fish will also lay their eggs on the glass to keep their babies metabolism down since they hatch when their embryo sac is depleted. They have to find food as small as 500 microns as soon as they eat. tldr: Over all the best places to look for fish eggs are either on the glass of the aquarium near the surface where their is more oxygen, in plants and coral, and in small caves just small enough for the parents to get in and out. If there are other fish species in the aquarium either the fish or the eggs themselves need to be removed to ensure something doesn't get a free meal. Many times the eggs will be eaten by a tank mate before someone even realized they are in the aquarium.
points and you can look at it in your aquarium
They do if they can't get out of the aquarium. In the wild, most fish don't have that option since many fish are like salmon in that once they've spawned (females laying their eggs, males fertilizing the eggs), the adults die and aren't around by the time the eggs start to hatch. Some fish breed several times in their lives but never see the offspring, but some others lay eggs, breed, and one or more adults will stay to defend the eggs and young for a time even after hatching. The true answer to your question is... It depends on what kind of fish you are talking/asking about, and whether they are in a natural body of water, or an aquarium. Some fish will even eat their own young if they're still in the area when their eggs start hatching. Guppies are one type that will do this.
a green spotted puffer fish egg looks like a fuzzy ball
look up shedds aquarium in Chicago
Because it makes more oxygen,which is good for the fish,but its your choice.'It also makes the tank look much nicer to look at and some gold fish might like to eat it :)
Yes, or the species would have died out with the first fish! The female lays eggs, which are then fertilised by the male. These in time will hatch into baby fish. Who ever had aquarium remembers their first fishes: guppies, mollies, platies, swordtails. They are livebearers, fishes that retain the eggs inside the body and give birth to live, free-swimming young that really look like baby fishes.
They may be copepods which are great for some fish are corals. There are other things they may be, depends on what they look like.
Its completely up to the owner of the aquarium.
I'm not certain that anyone has smelled or documented the odor of fish eggs other than those of caviar, which are said to smell like a 'sea breeze'; although that's not very descriptive if you've never smelled the sea.
Mosquito feces is hard to detect because of its small size. A female's feces is a reddish color and a male's is grey.
Hundreds of eggs. It is not likely that you will have them though. It is a difficult job to breed most species of sucking catfish.