Breeding Nets

[DeanoL83]

Hi guys,
 
I've had my 200L tank up and running for about a month now and to my surprise the other day I found a little fry swimming around.  One of my mollies must have given birth without me knowing.  I have only found one so I am guessing all the other fry have been eaten.
 
I think I have another mollie pregnant and a couple of platties. 
 
I have just purchased a breeding net that attaches to the inside of the tank which I should receive in the next week or so. 
http/www.ebay.com.au/itm/261261707093?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648
 
 
I know it's silly to buy it first and then ask questions, but that's what I've done lol.
 
Do people find the breeding nets successful?  I am assuming that I leave the top out of the water and catch the female and trap her in there - is that correct?  When is the best time to put my pregnant mollie/platy in the breeding net?  Just a day or two before I think she'll give birth or like a week before?
 
How long should the fry stay in the breeding net before I release them into the tank?
 
Should I find the surviving fry and place it in the net now, or if it's survived this long should it still be ok to swim around?
 
Thanks for the advice

 

[Byron]

Do not put the female molly in a breeding trap/net; this will severely stress her.  But you can catch the fry and rear them in the breeder.  Once they are a bit larger they can be released into the main tank.  If you have a good cover of floating plants, quite a number of fry will usually survive.  And as mollies give birth regularly to dozens of fry, you will probably have more than you can manage very soon.  It is fun though when little fish appear.
 
Byron.

 

[DeanoL83]

Thanks for the answer Byron. If the female is stressed will she abort the pregnancy? So, even if she is in the same tank and can see her tank mates that will stress her too much?

I can't find the one fry I had so thinking it has been eaten.

I've also purchased some floating hide-out plants for fry so I'm thinking I'll let he give birth naturally. The floating plants will help most survive for a while and I can scoop some into the breeding net afterwards. Is that the best way to do it???

Cheers

 

[Jamowens]

Sometimes fish get stuck between the glass & net , putting something like a magnetic glass cleaner in the gap to enlarge it stops you losing fish that get stuck . I use nets never leave the bottom grid in just pack the net with lots of plants for fry cover & keep the net at the back of the tank not the front , never had a problem with mother & fry .

 

[Lunar Jetman]

Personally I don't bother with this kind of thing. I did when I first started keeping fish (too long ago now to remember) but you soon realise that livebearers are very prolific breeders so you'll soon be overrun if you try and save every one you can.
 
I think its much better to let nature take its course and leave them in the tank. Some will hide and grow into adults whilst others will get eaten. I know it sounds a bit harsh but your tank will then reach natural stocking levels as those that can survive will.
 
If you do intend to keep some (maybe just the first couple of times perhaps so you can enjoy watching them grow) I'd keep them in the net until they're too big to be eaten by the tank's inhabitants.

My daughter has a tank in her room with livebearers in and all I've done is provide a few plants for the fry to hide in. it's a Roma 90 and is 2ft wide but there are plenty of fry that have survived into adulthood. She has a nice even balance of fish in her tank which is what we were aiming for. Some tiny fry that have managed to hide from hungry mouths and others in various stages of growth.

 

[Byron]

I agree with Lunar Jetman.
 
To answer your question Deano on stress, it is the close confinement of the net that stresses the fish.  Imagine how you'd feel if confined to a cage, not knowing what was going on or how long?  That's much the same thing.  Other fish in the tank are less likely to cause such stress, provided they are the right sort of tankmates to begin with.
 
Byron.

 

[DeanoL83]

Thanks for all the answers. 
 
Lunar Jetman, yeah this is my first real aquarium so I am a little excited about the prospect of watching some fry grow up.  I do want to get a few of the fry from the first batch or two surviving so I can see the fish at different stages.  I'm sure after the first few months and couple batches of fry the novelty will wear off and I will let nature take it's course.
 
I will most likely just let the mother give birth naturally in the tank.  Hopefully, some of the fry will find the floating hide-out plants that I will put in there, and then I will transfer the fry from there to the breeding net until they are large enough to be put back in the tank.
 
I have one male molly and four female molly.  Can I assume that he will be mating will all four of the females? Or does he just pick one as his mate?  He seems to devote most of his attention to the yellow molly, and ignore the other three (who were later additions to the tank).
 
Thanks for all the advice
Dean

 

[Byron]

Male libebearers will mate with any and all females of the species present in the tank.  And once they do, even without a male present the females can deliver several successive batches of fry; this is termed superfetation.  It is good that you have three females and one male; this should give the females some respite.
 
Byron.

 

[DeanoL83]

Yeah I read that the females can store sperm for up to 6 months which I find quite incredible!
 
Will the male molly breed with female platties I have in my tank?

 

[DreamertK]

No, they're different species.

 

[Byron]

Agree, though it is the genus not the species that determines this; cross-breeding is sometimes possible between different species within the same genus.  And it is true that what fish will sometimes do in an aquarium can be different from what they do in the habitat with respect to spawning across species.  This is because the two may never come into contact to begin with, or there are so many females of their own species that it is just doesn't occur.  
 
As far as I know, spawning can occur between different species within the same genus, at least sometimes.  For example, the platy (Xiphophorus maculatus) and the swordtail (Xiphophorus helleri) will cross-breed, which is how we came to have so many colour varieties of the swordtail, from the platy.  But mollies are in another genus, Poecilia, so one would not expect them to cross-breed with platy or swordtail.  Ichthyologists believe one reason is that the gonopodium of the males is positioned differently, so copulation with females of another genus is not likely.  But there may be other factors I'm sure.
 
Byron.

 

[DeanoL83]

Thanks for the reply. I had read before the guppies and mollies can occassionally cross-breed - does that mean they are from the same genus?
 
So platties and swordtails are from the same genus.
 
Guppies and mollies are from the same genus?
 
Correct?  Thanks

 

[DreamertK]

Guppy: Poecilia reticulata
 
Molly: Poecilia sphenops
 
Platy: Xiphophorus maculatus/variatus/helleri

 

[Byron]

The guppy and molly are for the present in the same genus, as DreamertK correctly set out, but this is not accepted by several ichthyologists today.  I like to know these things, but not everyone cares, so I'll summarize for those who are interested.
 
The genus Poecilia was originally established by Bloch & Schneider in 1801 for the guppy; the name comes from the Greek poikilos which means "with different colours," a suitable choice for the multi-coloured guppy male.  When Valenciennes described the molly in 1846 he placed it in the genus Mollienesia (as Mollienesia sphenops) that had earlier been erected by Lesueur in 1821; Mollienesia honours someone named "Monsieur Mollien," of whom I know nothing, but he may have been a friend of Lesueur.  In 1963, Rosen & Bailey transferred the molly into the genus Poecilia as they believed it was closely related to the guppy.
 
Presently [according to Fishbase] there are 40 distinct species in the genus Poecilia, of which one is the guppy (P. reticulata), two are Endlers (P. wingei and P. obscura) and the remaining species are all mollies.  And these are not variations of a species, but distinct individual species.  The type species for the genus is in fact one of the mollies, P. vivipara; type species means the species that was used to name the genus and that therefore contains all the traits of the genus, so that every new species assigned to this genus must bear all these specific traits.
 
At this point we turn our attention to the Endler.  This fish was first discovered in 1937 by Franklin Bond, but it remained undescribed or named; in 1975 John Endler found the fish and it was assumed he was the first, and thus the common name became "Endler's Guppy."  It was thought to be a form of the guppy until 2005 when it was described by Poeser, Kempkes & Isbrucker.  This trio of ichthyologists suggested that this species has sufficient differences from the molly species that they should not be in the same genus, and they proposed resurrecting the name Acanthophacelus as a subgenus of Poecilia.  Acanthophacelus had originally been erected by Eigenmann in 1907 when he described what he thought were new species that subsequently turned out to be conspecific with known species in Poecilia, so the name was then invalid [the first name assigned to a species must prevail according to set rules of nomenclature, unless there is valid reason under the rules].  This classification was "proposed," as is the normal scientific process, until further ichthyological examination confirms or refutes.  So the Endler is more correctly identified as Poecilia (Acanthophacelus) wingei.  In 2009, a trio of ichthyologists described another distinct "Endler" species and they used this classification, so this new species is now Poecilia (Acanthophacelus) obscura (Schories, Meyer & Schartl, 2009).
 
Several ichthyologists consider the guppy to be in the wrong genus too, and as it is very close to the Endler I have no doubt it will end up in the same genus after further study.  So, to show the significance of this to the question of the molly and guppy cross-breeding, there are ichthyologists who believe this is not likely.  Even though they are currently considered in the same genus, this may be in error, and if the differences between them should turn out to be significant, they might prevent cross-breeding.  I'm going from memory now, and would have to dig into my research to confirm, but I do recall some mention of the gonopodium being on the opposite side of the male of some species, and thus males can only breed with females that can accommodate this.  But as I say, I may be mixing things here, as it has been a couple years since I was digging into this.
 
Hope this has helped.
 
Byron.

 

[DeanoL83]

Wow thanks for the in-depth information Byron - you really are quite informed in this area!!!
 
I find it amazing that there is such debate amongst specialists.  Sounds like it's only a matter of time until someone finds enough proof to show that guppies and mollies are different enough to be in separate genuses.
 
Is there a website anywhere which lists (with photos) all the different types of mollies.  I am really intrigued by mollies in particular as I have a few in my tank and they look quite different so i'd love to try and identify which ones I do have.
 
Cheers,
Dean