Question:
Do Fish Sleep? [The Straits Times 1 Feb 2003 Classified Section]
It all depends on what you mean by sleep. Sleep can be defined as a period of rest in which the eyes are closed and there is little or no thought or movement. That is, sleeping means closing your eyes and resting.
THe 1st thing we notive is that most fish don't have eyelids (except for sharks). Also while some deep ocean fish never stop moving, a great many fishes live nearly motionless lives and many do so on a regular diurnal/noctural cycle. Some are active by day, and others by night.
So we cannot generalise and say that all fish sleep like we do, But most fish do rest. Usually they just blank their minds and do what we might call daydreaming. Some float in place, some wedge themselves into a spot in the mud or the coral, while some even build themselves a nest. While they are still keeping alert to danger, they will also be "sleeping".

Answer:

Do Fish Sleep? [The Straits Times 1 Feb 2003 Classified Section]
It all depends on what you mean by sleep. Sleep can be defined as a period of rest in which the eyes are closed and there is little or no thought or movement. That is, sleeping means closing your eyes and resting.
THe 1st thing we notive is that most fish don't have eyelids (except for sharks). Also while some deep ocean fish never stop moving, a great many fishes live nearly motionless lives and many do so on a regular diurnal/noctural cycle. Some are active by day, and others by night.
So we cannot generalise and say that all fish sleep like we do, But most fish do rest. Usually they just blank their minds and do what we might call daydreaming. Some float in place, some wedge themselves into a spot in the mud or the coral, while some even build themselves a nest. While they are still keeping alert to danger, they will also be "sleeping".

Answer:

Breeding Discus [The Straits Times 1 Feb 2003 Classified Section]
I would like to get my discus to breed. COuld you advise me how the fry should be taken care of?
Discus are a species that do provide parental care for their young, and this is especially crucial to fry that are a few days old. The fry feed off the highly nutritious body slime produced by both the parents. They would probably have a lower success rate of survival if separated from the parents.
In the wild, it is rare for parents to cannibalise their young. However, in tank-raised discus, this occasionally happens with the young parents during their 1st couple of spawnings as they are new to parenting.
Try breeding the pair for a couple of times and observe if the problem persists. If it does, then you have to either separate the fry from the parents and raise them in another tank, or prevent the same pair of discus from breeding.

Answer:

once read a book on fishes ...
If u notice clearly on a fish body ... u can see a horizontal dotted line across the mid section of the fish body.some are light but some are dark. Cant remember wat it is called .. it help e fish to sense danger or movement in the water .
and fish communicate with one another by relasing chemical from their body ..
Cant rellie remember the details .. mabi someone would like to correct it

Answer:


1. What is an aquarium?
Ans. An aquarium is a place where freshwater and salt-water animals and plants are kept, away from their natural habitat.
2. What are two things that animals produce that can affect water quality?
Ans. Animals produce solid wastes, excess food supports other microscopic organisms that compete for oxygen, and that fish produce poisonous ammonia.
3. Why must town water be checked before using it in an aquarium?
Ans. Aquariums cannot be filled with water straight out of the tap. Check town water before you fill your aquarium. It will contain chlorine which may be removed simply by letting the water stand in a container for 24 hours, or by bubbling air through it.
4. What happens to the dissolved oxygen as water is boiled?
Ans. Boiling the water will remove all gas, including oxygen, so if you get rid of the chlorine by boiling, bubble some air back through the water before putting the water in your aquarium .
5. What does the term water conditioning refer to and for how many weeks should water be conditioned?
Ans. The process where water is left in the dark for two weeks to allow anaerobic and aerobic bacteria to reach this equilibrium. At least two weeks is recommended to condition your water. The holding area should be dust-free and clean (as shown in Figure 150.3) where you can provide oxygen from a pump. While you are waiting for your water to condition, you may like to learn how to set up a small freshwater aquarium..
6. What is an under-gravel filter and what should it contain?
Ans. An under-gravel filter is a tray of gravel or shell grit at the bottom of the aquarium linked to an uplift water system which sucks water from the tray.
7. How does and air uplift tube work?
Ans. The air introduced into the uplift tube creates a vacuum which sucks aquarium water through the plates and along the channels (Figure 152.1). The under-gravel filter works on the principle of displacement by uplifting air as shown in the detail of Figure 152.2
8. What are some common micro-organisms found in the under-gravel filter of a marine aquarium?
Ans. Worms, bacteria and algae
9. What is a trickle filter and how is different from an under-gravel filter?
Ans. An alternative to the under-gravel filter is the trickle filter a filter containing biological filtration organisms outside the aquarium. Water is pumped up into the filter above the tank and allowed to gravity feed back into the aquarium. The box of the filter can contain expensive bioballs or inexpensive materials such as the plastic tops off drink bottles.
10. What is biological filtration and how does it work to remove harmful substances from your aquarium?
Ans. Biological filtration organisms are usually the algae, crustacea, worms and bacteria that grow in the under-gravel filter. As water passes over them, they take out the soluble animal wastes for food. The bacteria, algae and worms can be grown on plastic, gravel, glass beads anything that will not release into the water substances that will poison your animals.
11. Why is glass the most common material used to make aquariums?
Ans. Glass is most often used because it is cheap, easy to work with and lets lots of light into the water to increase photosynthesis.
12. Why are metals avoided in aquarium construction?
Ans. To avoid corrosion.
13. Why are sea urchins a reliable indicator to the health of your aquarium?
Ans. Echinoderms, sea urchins and even brittle stars can be kept but take care because they seem to die unpredictably and will readily foul a tank after they die. Sea urchins are a reliable indicator of the health of a marine aquarium. If they do poorly (drop spines) something is wrong, even when other organisms appear to be doing well.
14. What should you check daily in your aquarium?
Ans. You need to check the temperature daily with a thermometer and at the same time make sure the air stones are working and the water is lifting well out of the airlifts. This will ensure good water circulation and aeration. If algae grow on the glass, clean it off with a plastic washing up brush (which you do not use for anything else!).
15. How can chlorine be removed?
Ans. Leave the aquarium out in the Sun.
16. What type of glue is recommended to join glass sheets for aquariums?
Ans. Silicon
17. Why are the channels necessary under the gravel bed filter?
Ans. To allow the water a passage towards the air lift tube.
18. Why are nitrates important to plants?
Ans. They help them grow.

Answer:

I wonder how it feels like to sleep with your eyes opening?