Breeding Laimosemion xiphidius

Laimosemion xiphidius was originally discovered by Dr. Carl Ternetz in 1925, collected in 1978 by G. Oelker, and described by Huber in 1979 as Rivulus xiphidius.  It is found in small creeks in French Guiana, Brazil, and possibly Suriname.  They inhabit waters that are very soft and acidic, with plenty of tannins from decaying organic matter on the bottom.

Many people (myself included) are of the opinion that this is one of the most beautiful of all killies.  I’ve wanted to try breeding it since I first saw it in 2002, but until 2010 never gave it a try due to reports of it being difficult to spawn and raise. 

Here are some of the common recommendations for breeding them.  From cynolebias.org:

“They are not very prolific, producing a maximum of 15 eggs per week. Specimens need to be mature, aged between 12 and 18 months to breed. Breeders need to be well fed with live food. Eggs need hatching in aged tank water with a pH of 5 - 6 with a hardness of 0.2 - 1° DH. Some males are incapable of fertilising eggs.”

From itrainsfishes.net: “The species is not very productive and only regular water changes and enough small life food will bring them in a good breeding condition.”

From those two accounts, this fish should not be reproducing in my fish-room.  But I’ve been able to maintain this fish for 2 years and I’m raising the 3^rd generation now.  Here’s how I breed this beautiful fish:

I started initially with 1 pair obtained at Michiana’s Killifish Karnival in 2010.  They were probably about 8-10 months old.  I set them up in a 2.5 gallon tank half-filled with sphagnum moss.  Water was kept 80-100ppm hardness and about 80°F.  For comparison that’s 4.5-5.5°DH, a bit harder than recommended.  I change 80% of their water about once per month, with almost pure RO or rain water.  I mix enough tap water in to keep it above 80ppm.  I’m sure between water changes this value drops, but I’ve never measured it below 50ppm. 

I feed them baby brine every day, with occasional feedings of fruit flies, frozen bloodworms, daphnia and flakes.  I spotted my first fry about 6 weeks later, at more than ¼” long.  Once I’m sure I have a number of fry, I will set up another tank and move the parents.  I then slowly remove most of the moss a small amount at a time by hand.  Once the moss is removed, I count 

the fry and if needed move them to a 5 or 10 gallon tank for growing on. 

When raising fry I do more frequent water changes, and I’m much less picky about water conditions.  I use aged tap water, which for me is about 450 ppm, and change 50% of their water once every week.  They are fed pretty much the same diet as the parents, and while they aren’t fast growing the do grow well.  I set up new breeding pairs around 6 months of age, and try to keep at least 2 pairs at all times. 

Laimosemion xiphidius is significantly easier to breed and maintain and much less picky about water conditions than most articles will lead you to believe.  But there’s a catch.  It comes down to sex ratio.  I’ve been fairly lucky to get a ratio of 85% males to 15% females.  There doesn’t seem to be one key value that determines ratio.  Some people say hardness, some pH, others say temperature.  It could involve dissolved organics.  For this reason alone, this fish remains on the list of difficult fish and while it isn't rare it certainly isn't the easiest fish for find.



Laimosemion xiphidius FBS 95-2 Female

This is what my breeding setup looks like

 

Laimosemion xiphidius FBS 95-2 Male