[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Index by Month]

Evolution in a microcosm

So, last night I witnessed Evolution at work in my 29G plant tank. The tank contains a trio of Blue Rams, a couple black neons, 3 molly fry, 3 ottos, 2 SAEs and ~12 ghost shrimp, bunch of red ramshorn snails and MTS. Because this is a aquascaped tank, I didn't have any "normal" spawning locations, just a few artistically placed rocks and driftwood.

The tank stats are:
KH / GH: 3-4/6
CO2: 25-35ppm
pH: 6.65-6.70
NO3 - ~5-10 (added weekly for plants)
PO4 - ~0.5
Weekly water changes.
Temp ~81F

Anyhow, after I fed the fish their allotment of live blackworms, I moved on to feed my other tanks. I returned 15 minutes later, and sure enough, the male and the "alpha" female were dancing around a little depression in the substrate (flourite) hidden behind some tall plants. I peered in and could see ~75-100 eggs (not bad for a tiny female) right on the flourite. The male was busy fanning the eggs. The interesting part: the "beta" female, who lately has been chased by both the a-female and the male, kept coming up to the pit and appeared to "entice" the male away from the eggs. Then, she would circle around the whole tank while being pursued by either the male or both the male and a-female. A few times, the b-female would circle back to the pit and quickly gobble down a few eggs! The male would chase her away again, and the whole thing would start again! The male also began chasing the a-female around, allowing the beta-female even more snack time!

Evolution at work! The b-female was clearly eating the eggs to increase her fitness level and simultaneously reducing the chance of the a-female spreading her genes! Very interesting! Another consideration is that it is quite likely that the trio are genetically related -- probably even siblings -- as I got them from the LFS. In many higher animals, genetically related conspecifics often take _some_ responsibility for care of young -- eg. "aunt" chimps often take turns caring for baby chimps or watching juveniles while the mother gets some relaxation. Apparently not so with Rams!

I also think I was pretty lucky to get two true females and one male -- I was a bit worried after reading about the lack of females being imported from the Far East. Perhaps the trio was even from a local breeder.

Well, an hour later, I checked back on the tank and noticed that the male and alpha-female were doing a "spawning dance" on the other side of the tank near the driftwood. The female's ovipositor was still very extended and both had full coloration. The beta-female was no where in sight, and it looked like most of the eggs were gone. So, I am hoping they do better on the next round!

I am not prepared space-wise to dedicate a tank to breed these fish, but wouldn't mind having a successful spawn in their present tank. If anyone has suggestions that might help, I would appreciate it. I could pull out the other female, but think that she might be next in line to lay eggs! I added a small clay tray (for flower pots) with some fine sand in it, so maybe the Rams will like that more?

BTW - My new pair of A. trifasciata is settling in nicely and my new male double-red aggie is adjusting to his new home... Still seems a bit ragged, but hopefully some good food will fix him up soon!

MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx

------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com.