Looking for Lined Topminnow Breeding Info
Posted 25 January 2018 - 06:04 AM
I've had 2 male and one female Lined Topminnow since last fall. For the last couple months the smaller male has been asserting dominance over the other two. He lets them escape, but frequently singles them out and torpedos and bites them.
Last night I made a mess of things in my tank. I was doing a water change and preparing to add some cleaner shrimp to tackle the hair/string algae that is taking over. I managed to dump the lid into the tank, sending Salvinia minima throughout the top 1/3 of the water column for a short time, stirring up sediment, yadda yadda... With one of the sponges from the sponge filter being removed, rinsed, and replaced,and fishing out glass scrapers and refloating S. minima that had hung up on everything in the top third of the tank, the fishes in said tank were very much out of their normal routine before teh shrimp were added.
The point? Life in the tank was chaos. But as I watched to see if the shrimps would be relatively expensive feeders or survive at least long enough to eat some algae I noticed a definite change in the topminnows. The males were sparring, all flared up, fins and gill flaps stretched to bustin', side to side and "s" shaped, just a-whoopin' on each other. This was a fight, not the beat-down I'm accustomed to seeing. The female watched from the bottom, and would rise up to follow one of the males after their bouts of aggression. As far as I could tell, the boys wanted to fight but weren't much interested in her. I assumed this was spawning behavior and commenced searching the forum and internet for info. Found general info on topminnow spawning but not much specifically for Lined Topminnows. Anybody have some tips or know where to point me towards species specific intel? As luck would have it I have a supply of glassworms arriving courtesy Jenny today, so a live food source will be available for conditioning these guys if I decide to give it a try.
"No thanks, a third of a gopher would merely arouse my appetite..."
Posted 25 January 2018 - 10:57 AM
I have raised several generations of lined topminnows, but I just put a dozen or so adults in a stock tank outdoors, add plants for egg-laying sites and fry cover, and collect 3-5 times the number I put in as fall approaches.
Indoors, although I typically keep a dozen or more lined topminnows together in a 30 gallon tank, I occasionally get a dominant male that causes all the other fish to hide. I move the dominant male to a tank with other species of fish and sometimes another dominant male develops to do the same. Moving that one out has always resulted in no more dominant male activity with mixed sexes living together without major aggression. I have noticed that if I allow the dominant male situation to continue, I start losing male lined topminnows followed by the females dying off.
I stopped keeping goldenears, Fundulus chrysotus, due to repeated cases of a single male killing every other goldenear in the tank regardless of the number of fish or size of tank. These same goldenears have done well in outdoor 350 gallon stock tanks without obvious homicide.
Generally, non-native mop spawning (plant spawning) killifish are put together as pairs or trios (2 females with one male) after the sexes have been isolated from each other and fed well for several weeks. When put together, they typically spawn within a day or two, but will usually continue to spawn into floating mops for two to three weeks. Then the sexes are separated. I suggest that you try that.
Two males with one female are referred to as reverse trios in aquarium auctions and sell for less money than pairs or standard trios as they of less use to killifish breeders. In those cases, the female has probably selected one the males and will have nothing to do with the other male. If you put them together in a tank, the non-preferred male may kill the preferred male, but the remaining pair is likely to not spawn. The extra tanks and time in putting the three fish together as pairs is a hassle many breeders don't want to mess with.
I just sold all of my Aphenius mento adults and fry in my local club auction on Saturday because I got tired of all the tanks they were consuming with individual male separation. This is essentially a pupfish-like killifish native to Turkey and other isolated habitats including the Dead Sea of Israel.
Posted 25 January 2018 - 06:47 PM
Oh, last thing for this post. What would F. lineolatus fry eat at the beginning?
"No thanks, a third of a gopher would merely arouse my appetite..."
Posted 26 January 2018 - 12:15 PM
Golden topminnow males are much more aggressive than male lined topminnows. Some years I have trouble, others I don't. The dominance in male lined topminnows seems to show up more with older fish (those three or more years old) with less than a dozen fish in a 30 gallon tank. On the other hand, I typically put six pairs outdoors for the summer in a 350 gallon stock tank and see no signs of aggression. All of the fish school together. Adult fish don't school in the 30 gallon tank, which may explain some of the aggression. There may not be enough room for normal behavior. Younger fish school in aquaria with no observed serious aggression.
I assume that young fry eat protozoans, rotifers, and similar-sized prey. I use sponge filters in my aquaria and they are also well-planted. Both should supply tiny live food for the fry. The outdoor stock tanks also have plenty of plants to provide microbes for food. I do not use filters or aeration on my outdoor tanks. I have had good luck raising young fry around 1/4 inch long collected from stock tanks in the fall on newly hatched brine shrimp every other day alternated with Golden Pearls. I find that feeding brine shrimp every other day reduces that number of hydra in the tank.
Posted 29 January 2018 - 09:25 AM
Several months ago i watched a group of about 6-8 F. lineolatus near Spring Lake NC trying to bring down what looked like a small green caterpillar on a thread about 8" above the water. They jumped repeatedly at it, one or two at a time, until finally they knocked it down and realized it was a leaf. Then they swam off in a group looking for other things hanging above the water.
Hangin' on the Neuse
"Taxonomy is the diaper used to organize the mess of evolution into discrete packages" - M.Sandel
Posted 29 January 2018 - 05:24 PM
I do not have problems with any of our Fundulus jumping out of stock tanks during the summer. This includes F. lineolatus, F. chrysotus, F. cingulatus, and F. rubifrons. These are 350 gallon polyethylene round stock tanks that are about 6 feet in diameter and about 30 inches deep with straight sides. The sides extend 3-4 inches above the water level when completely filled. We have drilled small holes in the sidewalls at this level to allow drainage of excess water to prevent overflowing and fish loss during periods of frequent, heavy rainfall.
It is common to see the lined topminnows jump above the water surface in my stock tanks, but I don't remember seeing them more than an inch or two above the surface. I have seen topminnows jump higher in nature, but it has been in shallow water areas. I suspect that the shallow pond bottom allows additional thrust that is not available in the stock tanks. I have seen F. rubifrons jump about three inches off of a partially submerged water lily leaf.
I keep track of how many fish I introduce into the stock tanks in spring and typically recover all of them in the fall. I occasionally lose a fish or two, which would be expected from illness or injury during netting and establishment in the spring. I would be unlikely to find cadavers of leaping fish as the area is frequented by mice, cats, squirrels, raccoons, and ants.
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