Photo: A possible Poecilia reticulata (guppy) x Poecilia mexicana, Campeche (molly) hybrid in front of a grid to show size.
We found the fish in the above photograph January 15th of this year. Before I describe the fish and argue why I think it might be a hybrid, let me give you some background.
We breed most of our mouth-brooding cichlids in 300-gallon vats (see photo below), placing two to three males and up to 50 females in each vat. Each vat is equipped with devices we call cichlid hotels and fry cages. The cichlid hotels are made with 2” PVC cut to 12 inches in length with six cylinders of aquaculture netting tie-wrapped around them (see second photo). These provide shelter for the females when they tire of the amorous intentions of the males. We usually place five hotels on one side of the vat. We also place two or three fry cages in each vat. Fry cages made with 1/4” or 1/2” aquaculture netting forming an open topped cylinder about 30” in diameter. The same netting forms a bottom (see third photo) and four PVC legs keep the cylinder off the bottom of the vat. We place two cichlid hotels in each cage. These assemblies provide shelter for fry when the females release them.
A 300 gallon vat set up (minus the water) for cichlid breeding with three fry cages and various cichlid hotels.
A cichlid hotel used to provide cover for females, subordinates, and juveniles.
A fry cage used to provide cover for cichlid fry and juveniles.
A fry cage is placed in a breeding vat to provide a refuge for fry and juvenile fish.The breeders are placed in the 300-gallon vats equipped with the cichlid hotels and fry cages. We typically also stock the vats with feeder guppies (Poecilia reticulata) to provide forage for the fish and to inure them to the presence of small fish. Guppies, surprisingly, even in vats with predatory cichlids, reproduce well. We produce them in cichlid breeding vats and offer them to our wholesale customers as feeder fish. In some vats we also place mollies, both commercial aquarium strains and species such as Poecilia mexicana, P. latipinna, P. petenensis, and P. velifera. We are able to produce significant numbers of mollies this way. The breeders remain in the vats for three to four months, depending on the time of the year, before we harvest the vats. At harvest, we net out the fish, inventory the breeders, harvest the juveniles, and return the breeders to the vat for another breeding cycle. If there are guppies or mollies present, we restock breeders and harvest the surplus for sale.
On this particular January day, we harvested our Iodotropheus sprengerae (Rusty Cichlid) vat. In my never ending quest to increase production in each vat (Susie, wife and business manager, insists on profits), I continue to test poly-culture. Poly-culture is the growing of two or more species in the same space. In this case, I had stocked the vat with I. sprengerae breeders, feeder guppies, and Poecilia mexicana, Campeche (Campeche being the collection location in Mexico). As we sorted the fish, guppies were placed in a bucket to be separated into breeders to be returned to the vat and sale fish to go into 55-gallon holding vats. While selecting guppy breeders, I noticed one large, red tailed fish, too large to be a guppy but clearly not a P. mexicana. I put her in a jar for closer viewing.
I say “her,” because the fish had the typical fan shaped anal and ventral fins of a female Poeciliidae (the family both guppies and mollies belong to). Below, in the order of possible hybrid, guppy, and P. mexicana, are photos of females for comparison purposes. Note the male P. mexicana below the female.
Upon examination, the possible hybrid combined traits of both P. reticulata and P. mexicana.
- Her caudal fin shape said guppy, but she sported an orange caudal color reminiscent of that of a male P. mexicana instead of the clear caudal fins of female feeder guppies.
- Her head was more guppy-like with the eye closer to the upper edge of the head while the eye is set lower in P. mexicana.
- Her body, while more elongated than that of guppies or P. mexicana females, showed the dip after the dorsal typical of P. mexicana.
- Unlike guppy females, she showed no gravid spot, the black patch in front of the anal fin. Guppy females have it from birth. One can see through the transparent scales the guppy version of a uterus. Female P. mexicana do not show a gravid spot since their scales are not transparent.
- Her body color was rosy from the dorsal and anal fin back to the caudal, a pattern not shown by female P. mexicana but is in the males.
- The distance between the ventral fins and the anal fin was, like that of P. mexicana, greater than that of a guppy.
- She was much larger than the typical female feeder guppy just like female P. mexicana.
A possible female guppy x Poecilia mexicana, Campeche hybrid.
A female Poecilia reticulata, common name guppy.
Poecilia mexicana, Campeche female.
Many people have produced guppy/molly hybrids; it’s apparently easy. But I’ve failed to produce guppy/molly hybrids despite trying many times (so-called experts can and do fail). The interesting thing is that the hybrids are invariably (from what I hear) male and sterile. So, if this fish is truly a hybrid, it’s a first hybrid for me and a rarity in being female.
While we have over 700 vats, I only have 11 aquaria set up (well, set up if you count them being on stands usually without water or fish in the office). I picked a 40-gallon tank in which to put the fish. For companionship I took a male guppy from the vat she came from. I added some hornwort (Ceratophyllum demersum) and some scuds. Scuds are a small shrimp-like crustacean we raise for sale as food. Ours are a Gammarus species or maybe even a different genus. There are more than 90 species of freshwater scuds in North America alone. We’ve not been able to get anyone to identify our scuds despite shipping them to many universities. She remained there until a week ago when I took her out to pose for the photos herein. So far, she’s produced no fry.
So, what do you think? Hybrid or just a strange guppy? Let me know your thoughts.
Good fishkeeping!
Pam Crossett says
You might try her w/a male molly? Maybe she’d rather breed w/a bigger male? Since she was in the original tank w/both, I’d give her both, plus some other females (kinda to show her how it’s done) altho maybe you want to be able to ID the actual potential daddy? At any rate, just a thought.
charles says
Pam,
I’ll give her another month with the guppy and then add a male molly. Thanks for the suggestions.
Charles
Tony Griffitts says
Looks like a hermaphrodite guppy. Seen it in Endler’s Livebearers. It is very rare defect.
charles says
Tony,
That’s entirely possible. I’ve had old female guppies become masculinized, but this fish doesn’t have the thickening of the anal fins that those had.
Charles
Paul Kotarides says
Charles- Good choice to use a male guppy as a potential mate for the mystery fish. Male guppies are not as choosy about mates. A molly male might be hesitant. If the fish produces no fry -it most likely is either a true hybrid or a guppy with hermaphroditism. Then again it really looks like a hybrid- except for its guppy-like head. Most hybrids I’ve seen look a bit more molly-like in head shape.
I believe you said at one time you had some guppies from a delta strain in that vat too- besides the feeder guppies. . Perhaps it’s a freakishly large female guppy showing its delta ancestry in its caudal color?
Rodrigo says
Why breed it? It will just make a big mess out of the species.
Charles Clapsaddle says
Rodrigo, Our hobby, especially the livebearer side, was built on hybrids. If you raise commercial swordtails, platies, and mollies, you are raising hybrids. Also, it is scientifically interesting to see if such hybrids are fertile. Charles
Mike Crowl says
Hello, I enjoyed reading about the fish. The back story was interesting also. I found a possible guppy/molly hybrid too. The mollies, P mexicana I think we’re fish I collected near Bonita Springs Fl. They were in a coastal stream. The guppy’s were a green Moscow that bred true. I placed the fish in tubs outdoors for the summer. When they were brought in for overwintering, there was a male molly in the guppy tub and one young fry that grew into a fish larger than both suspected parent species. The base body color was the gray of the mollies but it’s caudal fin was more rounded and a light shade of yellow/ green. There were also some colored patterning on the posterior half of the body. I placed the suspected hybrid with virgin females of both molly and guppy’s. Never had any gravid females though. When the fish died, I preserved it in the freezer. My wife “loved” this. I am interested to see more stories from people who have had similar experiences.
Charles Clapsaddle says
Mike,
Sorry for the tardy reply. I’ve since collected a few more, all females, all of which have failed to produce fry while put with males of both species. I correspond with a hobbyist who routinely produces hybrids using male mollies and female guppies. His hybrids are always male and seem infertile.
Charles
David Graefe says
hallo habe jetzt ein ähnliches tier in ein zoohandlung gefunden riesiges weibchen ! körper gleich wie auf diesem bild aber alles flossen grösser und gelb orange. mit kein guppy weibchen vergleichbar was ich je gesehen habe.
Charles Clapsaddle says
David,
Here is your message translated…I think:
“Hello I have now found a similar animal in a zoo store giant female! Body same as in this picture but everything flowed bigger and yellow orange. with no guppy female comparable to what I have ever seen”
I’m getting more and more reports of molly/guppy hybrids. So far they seem sterile or all male.
Charles
Carol says
Hi Charles,
I have recently discovered male and female guppy(m)/mollie(f) hybrids in my 240l tank. I have only 1 female blonde lyretail mollie, she was the sole offspring of white sailfin mollie(m)/orange lyretail mollie(f). The obvious guppy/mollie hybrids are blonde, both males and females maturing and look very healthy. The males are beginning to colour up but staying within the blonde/gold/yellow/rose colour range and I must say look rather beautiful. I will need to separate out the other juveniles to see if there are other hybrids with the darker guppy colouring (as there were male/female guppies breeding, so most of the offspring are guppies). I’m unable to move them out of the tank at present and although not intending to breed them, may have some in the future, due to length of time together, if they turn out to be fertile. I too have read they are usually sterile, so not expecting any. Additionally, I have 1 blonde definite guppy/mollie hybrid female that has a part visible gravid spot, which was unexpected. I will keep you informed if that’s useful.
Charles Clapsaddle says
Carol, Sounds interesting. We keep getting hybrids from cichlid breeding vats in which we keep Poecilia mexicana and feeder guppies for the cichlids. These fish do remarkably well and have growing populations. In vats where we have both species, we get females that are apparent hybrids. None have ever produced offspring. I’ve corresponded with people who get hybrids, but they are all male and sterile. Please let me know your results,
Charles
Haley says
This is all so incredibly interesting. I just was given a molly, and while considering placing it in my guppy/cichlid tank I came upon your article! It seems a guppy I had aquired from a pond guppy breeder is exatly as pictured- but she is pregnant now! She was so much larger than the rest when I got her, I had never seen one so large but thought it was a beefy male. Imagine my surprise when she started ballooning too, and then now theres the grand possibility that pond also had hybrids or mollies in it…. I’m fairly shocked. I’m headed off to do more research, but would love to know if youve had fertility success yet! Cheers, Haley
Charles Clapsaddle says
Haley, Please keep me posted on your fish. If you can take photos, please send them to me at charles@goliadfarms.com.
Charles
Brody says
Thats cool I myself have been keeping mollies and guppies together for a while but Ive never got hybrids (which isnt really suprising to me)
Charles Clapsaddle says
Brody,
First, sorry for the tardy reply. Your message just appeared. We keep shortfin mollies (mostly with Poecilia mexicana heritage) and feeder guppies in 300-gallon cichlid breeding vats. We get a few obvious hybrids out of a few thousand fish.
Charles