How to sex coral red pencilfish?

[koel9]

How will you know if it's a male or female coral-red pencil, when you see one?

[Zenislev]

Not much of a bright red color, the more dull ones. Their pics can be found online...just click the Search button.

[koel9]

next time you come across a tank of coralred, look closely at the dorsal fin.

The males will have a small white marking near the base, even young ones.
Some females exhibite strong colours as well, and as these fishes are imported wild-caught, the males may also have dull colouring when they are stressed.

If you do get them to spawn in captivity, you could claim some measure of fame

cheers

[Quixotic]

Dr. Karel Zahradka has bred Nannostomus mortenthaleri before, but in the article in PFK magazine, it was not mentioned of the white marking being a sign of sexual dimorphism. It may be that the white marking is not realiable enough as a distinguishing feature.

The more realiable way to sex them is via the colour of the anal fin. In the males, the anal fin has a dark red rim, while in females the rim is lighter.

The article, including pictures of the embryo developement, can be found here, http://www.practicalfishkeeping.co.u...article_id=620

[celticfish]

it may be out-of-topic but i think this might interest someone whose looking into coral reds.

i find coral reds seem to be much easier to sex than the "purple" varient.
i had 11 pcs of purples... now down to 7pcs.
they dont have the white or the redder anal fin for the males.
in this regard you may feel they are less colourful than coral reds.
also, i find their reds are not as intense as the coral reds.

i'm guessing the males are just redder overall than the female.
but i cannot, even if my life depended on it, seem to figure any dimorphism for these varients.
or find any litreture/paper that discuss dimorphism for this varient.

also, this varient, though a tad pricer than coral red, don't seek to kill one another in a small tank.
coral reds are vey aggresive to one another!
my last lot of coral reds fought with one another till it was "last fish standing"!
also, i find they are more subceptable to succumb to infections or disease easily.
some of mine died with no visible behaviour warnings.

the purples are a better bet on the above points IMHO.
as mentioned though pricier, you will find the "returns" better than the coral reds.
my purples have so far fared my better than my coral reds.
the ones that passed on where due to my neglect on their tank and suicides (jumping).