Crenicichla Regani

[dhm325]

I have two pair that have spawned in the last 3 weeks. I have read that the ratio of male to female fry is temperature dependant. Does anyone know what temperature will yield an approximately 50/50 ratio? Thanks.

 

[Mike Wise]

I have never heard or read that sex ratios in Crenicara species are temperature dependent. I would be very interested to learn where you found this.

 

[specJ]

i think he was asking about crenicichla.

 

[Mike Wise]

Sorry, I meant to write Crenicichla. I have never heard or read that sex was temperature dependent for Crenicichla either.

 

[dhm325]

The reference that I remember is in Mergus Cichlid Atlas V.1 on page 1044 (top left of page) in the discussion of C. Regani. There is a statement that "Interestingly, temperature plays a dominant role in sex determination (for futher details, see the remarks in the species description of C. notophthalmus)." However, there is no mention of a temperature band that would yield a roughly even ratio for C. Regani.

The referenced discussion of Crenicichla Notophthalmus is on page 1038 (bottom left of page) under "Remarks" and refers to "various species of dwarf crenicicla" and states that "temperature determines sex." Again there is no mention of a specific termpertature band.

However, the discussion of Crenicichla wallacii, on page 1054, includes a statement that "all specimens reared at 23 [degrees]C were female, whereas all of those kept at 29 [degrees]C were male." This seems like a fairly wide band, I will try keeping it in the middle.

I was hoping that someone had first hand experience with C. Regani fry. If you have, please let me know. Thanks.

 

[Mike Wise]

Must have missed this one. I have never heard or read of temperature playing a role among Crenicichla - except there. Interestingly, Uwe doesn't provide any numbers like he did with apisto species. I will say that more & more pike people are beginning to think that the 'species' C. regani is a 'superspecies' in the sense of A. agassizii. Each geographical population lives in somewhat different water temperature & chemistry. I guess that, if you know which population you have, you would be most successful simulating those conditions.

 

[dhm325]

Thanks Mike.

 

[Apistomaster]

Must have missed this one. I have never heard or read of temperature playing a role among Crenicichla - except there. Interestingly, Uwe doesn't provide any numbers like he did with apisto species. I will say that more & more pike people are beginning to think that the 'species' C. regani is a 'superspecies' in the sense of A. agassizii. Each geographical population lives in somewhat different water temperature & chemistry. I guess that, if you know which population you have, you would be most successful simulating those conditions.

Hi Mike,
You bring up a good point. I have been wondering about the C. regani as an A. agassizi-like group of geographic poulations or subspecies. I have only begun dabbling in Dwarf Pikes this past year and most recently working with C regani. I guess this is an inevitable question with any species with a large range. Presumably, if you buy a from one lot your chances are a little better that they come from within a particular collecting region but one never knows for certain unless you get to collect your own fish.

I may be way off base but I have a little trouble with the pH or temperature playing such an important role in sex determination. I can't say very much until I raise some spawns. I do have two pairs out of six fish from the same source set up for spawning attempts. I am paying more attention to using soft acid water and am making an assumption that 82F is a reasonable starting point.

I do wish I had a supply of cichlid fry as a conditioning food. I cringe at the idea of having some Convicts in the house. I would mind the more civilized Rainbow Cichlids but I haven't seen them around the PNW in quite awhile.

 

[pikette]

I used to cringe about those convicts too. I finally got a group of Honduran Red Points to fit the bill.


Francine

 

[Apistomaster]

I was wondering whahether your C. regani that spawn are getting live fish as part of their diet? I have been told it is a big plus.

I found one of my set up pairs is now just one large male this morning. I have two spares but they never seemd like they fought. Maybe too much blackworms in the diet. I don't usually blame everything on blackworms but this last batch wasn't as nice as usual. I go through one to one and a half pounds a week with all my catfish and discus it's easy to do and that is just ~25% of their overall diet.

Red points would be OK if I can find them. I live in the African lake Cichlid Twilight Zone kind of an area.

 

[pikette]

I have never intentionally fed my dwarf pikes other fish. The larger pikes like the sp. 'Pacaya and the acutirostris get all the live fish. It's a good way to administer meds for me. I gut load the feeders and before they digest their food they go into a pike tank. The dwarfs, on the other hand, usual diet consists of blackworms, frozen bloodworms, and chopped up krill. When things get hectic, and I am not able to feed the fishroom everyday, everybody gets flakes or NLS.

Francine

 

[dhm325]

I did not feed any live fish to either pair of C. Regani. I feed them frozen blood worms and live black worms.