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Spawning Methods by Crabros


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#1 crabros

crabros
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  • Joined: 20-October 06

Posted 20 October 2006 - 05:44 PM

Hi All,

When I was first introduced to aquarium fish I didn’t know much about how fish reproduced or spawned.
I didn’t know some fish lay eggs on rocks and thought it was weird for female mouth brooding fish could raise fry in the mouth. I was later too learn that some male and female fish share mouth brooding duties.

In this article I'm going to try and explain how some fish spawn.

The first and easiest method I will talk about is substrate spawning fish.

The fish in this group are from locations from Central America most South American species and a fair few from West African are all substrate spawners.

How they spawn:
The eggs are laid directly onto a chosen surface by the female fish. This could be anything from plant matter, rocks, in caves, on wood even on the substrate where they live in the wild. Once the eggs are fertilized by the male they will be guarded and fanned by both parents to keep the eggs oxygenated.

How the eggs are cared for:
The female usually takes care of the eggs and the males usually guard and protect the breeding territory. The territory can be from a few square inches to a few meters in all directions. Big fish that protect a large area are usually the ones that give the breeder most grief as you will see all the others hanging in the corner of a 4 foot tank unable to move in fear of aggression.
The eggs generally hatch around fours days and the fry are hopeless. The parents will usually dig a pit away from the spawning site and hide the young wrigglers sometimes they will hide them in caves or pots. Around the 5-7 day mark they will start swimming around and are escorted by both parents. The time parents guard them for will vary a lot. Most will guard them until sub adults. The size of the spawn will vary in size from dwarfs with up to 20 and the bigger fish over 100.
Due to the vulnerability of the eggs and free swimming fry a lot of substrate spawners could become a meal to other fish. So if you can raise just a handful to adulthood the spawn is a success.

The second method of spawning is called mouth brooding.

The fish in this main group are from locations from Lake Malawi, Lake Victoria, Lake Tanganyika.

How they spawn:

The eggs are picked up and cared for by the female in her mouth is known as the buccal cavity. South American Cichlids are also known as delayed mouth brooders as after a few hours they will pick up the eggs from the substrate and start mouth brooding.
Eggs are either fertilized as they are laid by the female or after they are picked up by the female. With the later the female mouths the males vent near the anal fin which usually has egg spots as the female tries picking them up the male will squirt his milt into her mouth..
Once spawning has been completed the female departs and the female will brood the eggs.
In the lakes some females will brood in large schools to further protect them and the fry. Once the female has is brooding she will not eat usually. The females usually will not eat for anywhere from 10 - 16 days. It has been know some will hold up to a month depending on the species. The average spawn time is usually between 10 -16 days from egg to fry.
The female will then release the fry on and off from her mouth for a few days for protection until they are a bit bigger in size.
The main problem the breeder will face with these fish in an aquarium environment is premature release of eggs or fry or the female will eat them. Females will also try and eat with the mouthful. The cause from this is the female could be immature the eggs maybe infertile or harassment from the male or other fish.
The average size of a spawn will be between 10 to 40 plus with very rarely any major deformities. Some species will only produce 2-6 fry like Leptosoma and Tropheous any more than that is a great going.

So there you have it I hope you have learned something new here in our great hobby. If your lucky too have a few tanks have a crack at spawning the 2 different types of fish. I suggest you read up on the species you want too breed and have a go at breeding them. It is a great experience to bred fish but in my time in the hobby it is harder to bred and raise the egg laying fish.

All the best

Have a good day

Brett




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