groth rate C.venezuelanus

joern · Post by **joern** » 04 Jun 2007, 08:38

Hi,

a few weeks a bought a dozen of C.venezuelanus, someting abaut 2,5cm long.

Problem: the hardly grow....

Parallel I got a group of C. "green stripe", these were silghtly smaller during arrival...and now reached something between 3 und 3,5cm (all TL, living in the same tank.
All other Cory I had grew faster...

There are several reports on slowly growing venezuelanus....but this is really slow...looks a little, they grew nothing...or just milimetes..

How slow do they grew ?
What age might have they on 2,5cm TL ? And when will they reach full size or showing sexual activity ?

Fpr the case, the grow along at this speed, they will reach sexual activity in more than a year..this means in their 2nd life year.
I can hardly beleve, thar this is the case for such a small cory (although this is for the larger C. oder Brochis)

Or do they have a larger pause in growing ? My C.multimacualtus do like that (also observed by other breeders)..growing uo relative "normal" to about 2 or 2,5cm and than having stop growing for several month and than starting again...

kim m · Post by **kim m** » 05 Jun 2007, 08:46

I've bred all 3 species and found C. multimaculatus to be the slowest, no doubt.

Venezuelanus grow fairly quickly to 2-2½ cm. (2-3 months approx.), but I have yet to breed a fish that grow faster than green lasers, wich grew to 3,5 cm. total length 8 weeks after hatching! Most species grow to 2-3 cm. rather fast i think, then they slow down a bit.

cartouche · Post by **cartouche** » 06 Jun 2007, 02:14

I bought a group of Venezuelanus (2,5-3 cm) in October and they have grown up only little. However, they already spawned in April for the first time (165 eggs).

A question for Kim M: Do they need some special water for the development of eggs? All the eggs namely turned white on the 4th day. My water has 8,5 dGH, pH 7.

kim m · Post by **kim m** » 06 Jun 2007, 04:55

I use rainwater (pH 6,5 TDS 65)...I can't get them to spawn in tapwater (pH 7,4, TDS 400). I have no problems with egg-development in rainwater. I guess I have a 90% hatch rate with this species.

cartouche · Post by **cartouche** » 26 Jun 2007, 01:03

Last week they spawned again, 185 eggs, and I placed them into water with various chemistry, from 4,3 dGH to 1,8 dGH, pH around 6,5. It seems that the development at 1,8 and 3,0 dGH was better than at 4,3 dGH, but the overall success was not big - only 35 pieces hatched. The remaining eggs suddenly turned white on the 4th day. There was no clear trend, however, and I think that it may have more in common with the density of eggs in hatching containers than with chemistry.

Since the water in the hatching containers was not good and I had no further rain water, I had to place them into tap water (8,5 dGH, pH 7,5) shortly after hatching. In contrast with C. duplicareus, who don't mind such a treatment, the fry of venezuelanus couldn't stand it, suffered from dropsy, and all died within 3 days. Hopefully the next spawning will be more successful.