Help share your tips in keeping Nannostomus mortenthaleri

**Morgan01** · 24th Dec 2008, 17:43

Dear all can you please share your success stories in keeping these beautiful coral red pencils?

Been a challenge for me. Thank you

**Jungle-mania** · 25th Dec 2008, 02:00

To keep them healthy, here are a few tips;
1. Java moss, seems to induce breeding.
2. Maintain water parameter
3. Try to avoid keeping other fishes
4. Avoid buying live food till they are more stable, I know about the scare of introducing bacteria to the tank through live food, but I never had casualty, only with heavy water change.
5. Alot of foilage and an empty mid tank range region for them to swim.

**Quixotic** · 26th Dec 2008, 19:05

Firstly, when choosing the fish from the LFS, avoid buying fish that is breathing heavily as they don't seem to be in the best of health.

Also, in my experience, avoid buying fish that has a lesion (pale patch) on the body, even if it is a very small one. I am not too sure what they are, could be some disease or result of wounds. A fish with such lesion normally won't last long.

They also need large tanks. The alpha male may eventually kill the other males if the tank size isn't big enough.

As they spend time mostly in the upper and mid level regions, thick floating vegetation will help to provide hiding places and diffuse territorial disputes.

They seem to be sensitive to deterioration of water quality too.

**sadie** · 26th Dec 2008, 20:58

I have 4 in a 1.5ft tank together with 3 otos and they have been here for more than 3 weeks. They are feeding on tetra bits and no issue with it. So far all have been healthy.

**TyroneGenade** · 3rd Aug 2009, 23:34

Hello,

Anyone bred these? How fast do the fry grow, i.e. how long before they colour up?

Thanks

**apistomaster** · 26th Aug 2009, 09:20

N. mortenthaleri breed in the same manner as other Nannostomus spp. The fry are small and require infusoria for several weeks. At around 10 days free swimming you should begin introducing other live foods like Walter Worms and Artenia Nauplii. Since their growth can be uneven one should overlap infusoria with the larger food until it is clear all the fry can take nauplii.
They require very soft acid water and an egg grate should be used because the breeders will turn and eat thei eggs as fastas they release them.
Fry grow very slowly for the first 3 months but they reach breeding size in about 9-10 months.

They can be aggressive towards one another so provide plenty of cover and do not over crowd them.

**TyroneGenade** · 2nd Sep 2009, 22:32

Thanks for the advice!

**NOVA** · 23rd Nov 2009, 07:22

Originally Posted by sadie

I have 4 in a 1.5ft tank together with 3 otos and they have been here for more than 3 weeks. They are feeding on tetra bits and no issue with it. So far all have been healthy.

Originally Posted by apistomaster

N. mortenthaleri breed in the same manner as other Nannostomus spp. The fry are small and require infusoria for several weeks. At around 10 days free swimming you should begin introducing other live foods like Walter Worms and Artenia Nauplii. Since their growth can be uneven one should overlap infusoria with the larger food until it is clear all the fry can take nauplii.
They require very soft acid water and an egg grate should be used because the breeders will turn and eat thei eggs as fastas they release them.
Fry grow very slowly for the first 3 months but they reach breeding size in about 9-10 months.

They can be aggressive towards one another so provide plenty of cover and do not over crowd them.

High Tech Planted tank, 240L planted heavily P.H 6.8.
If my Tap water has KH of about 11, will they do?
If they won't live under these condition I may use RO water. In such case what are the KH, GH & PH paramaters recommended?

**stormhawk** · 23rd Nov 2009, 14:32

Originally Posted by TyroneGenade

Hello,

Anyone bred these? How fast do the fry grow, i.e. how long before they colour up?

Thanks

An online breeding account by Dr Karel Zahradka at PFK:

http://www.practicalfishkeeping.co.u...article_id=620

Like Quixotic said, the males are very aggressive in confined spaces. This seems to apply to all the pencilfish species irregardless of the sex. In small numbers like a trio, the weakest is usually bullied to death.

I had a trio of beckfordi, and the biggest one practically killed the smallest one.

**tetroid** · 12th Dec 2009, 12:30

Yeah, they're mean. Three lined pencilfish are even meaner though. Thugs, if you ask me.

Anyway, I find coral reds just need soft water and good food. They aren't too delicate, but they really do seem to need water that is low in carbonate and general hardness. Here in Ottawa, the people I know of that had trouble keeping them alive all had hard water.

As for breeding... I recently tried to get my crenuchus spilurus to spawn in my community tank by hardening the water for a few weeks and feeding them sparingly, then rapidly softening the water with peat and feeding them heavily. All the fish in the tank started displaying to each other after that, including my coral red pencilfish.

Here's some video of my nannostomus mortenthaleri displaying to each other. You'll see a little bit of courting at the end. When the male flicks his body, he's trying to get the female to follow him into the plants.

Nannostomus mortenthaleri display.

**DBM** · 28th Dec 2009, 06:57

Tetroid, where'd you find these? I'm in Canada as well and am looking for some.

**tetroid** · 30th Dec 2009, 10:50

I got all of mine from Big Al's in Ottawa. They get them when they are in season, which runs from around November to around April. Just ask them when their next Peruvian shipment comes in. These fish aren't too hard to find - paying for them is the hard part.