Early Christmas gift!

[Hellfishguy]

Woke up on 12/15 to find my female Dicrossus maculatus guarding her first spawn on top of an Anubias leaf. The eggs hatched out on 12/18. Since then she's been moving the larvae to various Anubias leaves, but today she placed them on an oak leaf right near the front glass. Been looking forward to seeing those yellow ventrals for a long time!

 

[gerald]

Congrats .. i hope they survive and grow. Are these the "Santarem" form of D. maculatus (north end of Rio Tapajos)?

 

[Hellfishguy]

I know that they're wild-caught, but from where I haven't a clue. I got the female from Jeff Michels & the males from an LFS (!), where they were labeled as checkerboard barbs.

 

[Hellfishguy]

D. maculata fry born 01/03/16. A bug's ear has nothing on these guys!

 

[MickeM]

Awesome!!

 

[gerald]

Boy they're cute - looking nice and healthy too. Did you ever get a decent photo of the father?

 

[Hellfishguy]

I can never get a photo that does him justice. When he spars with my other male the colors are mind-blowing.

 

[Lisachromis]

The colours look good to me!

 

[Hellfishguy]

The fry are now 4 months old & the largest top out at about 1 1/4 inches. At what age do they become sexable?

 

[MickeM]

At this size.. I would say/guess quite soon..(at least if no other stronger/dominant fish is in the same tank!!)

Don`t know if the gender-ratio follows the temp., like with many Apistos..
..where the gender is developed "according" to what temp. is in the water ..,the first weeks as free-swimming fry..!! ??
(I guess this still is the present /most "correct" thesis..???)

 

[Hellfishguy]

I'd heard that pH determined the sex ratio in D. maculatus, with a low pH (5.0 - 5.5) resulting in a majority of females. I've been raising my fry in very soft water (gH >1<) with a pH close to neutral, which are supposedly the conditions in their natural biotope. I'm hoping for a more balanced sex ratio.

 

[MickeM]

OK.. interesting...
This is the case with other fishes too I`ve heard (killie-fishes)...but I don`t know if it has been verified/stated in experiments..

 

[Hellfishguy]

Time will tell. At the rate they're growing I should be able to accurately sex them sometime in mid-2020.

 

[gerald]

That's not bad for 4 months old, and they do look healthy and have good body form. Assuming you plan to keep these mac's going for multiple generations, dont just pick the largest ones to keep for your next generation. "Late-bloomers" can often have the best colors, from what i've seen with A. macmasteri and P. pulcher that i've maintained over multiple generations.

 

[Mike Wise]

I've never heard/read that the sex ratio of Dicrossus is pH dependent. Is this anecdotal (hearsay) or is there a study on this? I do agree that D. maculatus is from clearwater streams with very soft, near neutral water values, so its a good place to start with breeding.

 

[Hellfishguy]

In the Linke/Staeck book they state that in broods raised with low pH values ( I assume 5.0 or so ) only 5% of the young were males.

 

[Mike Wise]

OK, I'll look it up. Must have missed it. Thanks.

 

[gerald]

Unless they controlled for other factors (temp, etc) with other batches of fry, that may not be a reliable observation. But it does show that some environmental variables are probably responsible for sex determination, beyond simple X-Y genetic determination..

 

[gerald]

Hellfishguy - do you still have these D.mac's? I need a couple females.
If by chance you need males, Don Kinyon in VA has extra males.

 

[gerald]

Don K just told me that his pair came from you, so my males are grandsons of your fish.
If you (or anyone) knows of other folks in USA keeping D. maculatus, please let me know.