Monday, 28 November 2011

Understanding Fish Breeding Techniques

At one point or another if your pet fish is living comfortably and in healthy state, soon enough you will find little fry swimming in tank. As an aquarist, this is perhaps the most interesting subject of fish keeping because the excitement to see the fish grow from a tiny dot-like fish to become a fully grown adult is indeed satisfying. You might also want to collect the newborns for conservation purpose or sometimes even without your intervention, the fish will reproduce by themselves and the next thing you know, there will be some fry hiding among the aquatic plants. This is especially important if you are keeping rare and exotic fish species and you will want to collect the next generation of fry so that there will be continuity of your effort or maybe for commercial purposes to profit from the sales of the newborn fish. Captive breeding is also the only answer to ensure that aquarium fish species in the world are maintained as natural environmental condition keeps on degrading due to over pollution.

There are few major concerns when it comes to fish breeding. As a responsible owner, it is your job and duty to ensure that the young fish fry has enough space to live in and never neglect their well beings. Although at times, the routine is actually unplanned, it is still your responsibility to ensure there is as much humane treatment as possible to take care of the fish and if you are unable to provide your best commitment, it would be a good idea to give away the newborn fish to other owners who will better appreciate them. Another issue facing aquarium fish breeding is on the problem caused by inbreeding. Far too many stocks actually turn out to be inferior in terms of coloration, size, reduced hardiness and susceptibility to disease because these fishes were subject to line breeding occurring among the siblings. As a result, the fish that you see today is nothing compared to their parents caught from the wild. As mentioned earlier, captive-bred fish also produce stocks which are low quality and as a result often get rejected and thrown away.

Examples of egg layers. Rasbora and Neon Tetra fish

Producing high quality fish
In order to produce top notch quality fish, there are few considerations that you will need to take care of. First, selection of breeding partner is important, second, if possible avoid line breeding and third, try to cull the fish which are deformed and deemed low in quality. Selection of breeding partner should be simple because most of the times you can control which fish you want to select to become parents but there is also some tricky process whereby certain fish types like cichlids will only pair up on their own. These fish can be extremely unpredictable and will end up rejecting the partner which you select for them. Thus there is little on what you can do here unless it is other types of fish. In order to avoid line breeding, you can actually approach members in your local community fish club or friends and ask around whether they have the same mature stock. This will ensure that high quality fry are produced which are more beautiful and retains some of the desired characteristic from the parent fish. In a batch of fry, not all will end up achieving equal growth rate. Some are very dull in colors, others deformed, while there a few which didn’t catch up at all in terms of size. Therefore, culling should be carried out just like natural selection process in the wild so that only the strongest, most mature are retained to produce the future generation.

Different fishes have their own ways of reproduction and how they will care for the young. There are basically two groups; one is the egg-layers fish and the other one which will produce free swimming fry, also called live-bearers. Goldfish, discus, most cichlids and tetra fish all belong to the egg laying group while live-bearers like guppies, swordtails and platy will give birth to larger-sized fry which are already able to fend for themselves. Most fishes are known to leave their young offspring, after they have given birth. Most do not even provide care but there are others like cichlids which are very protective and will aggressively attack intruders if they sense danger. Most fishes will leave the eggs scattered while some parents will even devour the own eggs. Guppies and swordtails which are live bearers are also known to hunt down and eat their own offspring and that is the most shocking thing that you will ever find out. Therefore if you have intention to collect all specimens and do your own selection later part, then the best thing to do is that the parents should be transferred to their own breeding tank and then removed once the eggs are laid or the fries are dropped. This is to ensure you have the highest survival rate so that later you can cull and select the ones with the best features. Thus, if you have community aquarium whereby it is heavily stocked, normally you will find that very few offspring actually managed to survive and avoid all the predators.

Conditions for breeding
In order to encourage your fish to breed, the living environmental conditions like water temperature, pH and oxygen content must be at the right level and suitable for them. Sometimes you can induce breeding by introducing variety of fish diet supplying more live foods compared to the dry pellets. Most fishes require large breeding space to move around and some species like the cichlids require rocky type of setups like stone to declare as their breeding spot. Other fish like the goldfish will start to spawn with presence of a lot of live aquatic plants but there are some which do not require any of these conditions and will happily reproduce. Most of the time, fish owners prefer for the affair to be carried out and done in another separate tank rather than the main display aquarium so that the breeding pair can have better privacy and more control can be exerted especially with creating different breeding environment. Sometimes, not all fishes will readily breed on their own effort without your intervention and because of this reason; techniques were developed to use artificial methods like hand-spawning. This is especially important for those types of fish species which are generally slow swimmers, inactive in nature or they have limited bodily capability for example poor eye-sight like the bubble-eye goldfish. Dealing with egg layers are even more complicated because sometimes even when you managed to get them to spawn and release the eggs, not all of it will be fertile and most will be subjected to fungus infection. Certain species will only breed during certain period of time or seasons and thus, it will be quite difficult to actually catch them in their act and plan for the breeding program.

More about fish reproduction: How cichlids fish care for their young fry

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