Fish Characters

[georgedv]

I have two 29Gal hi tanks, side by side. They are decorated using same substrate, plants, wood work, rocks, caves, water source, water parameters, temp..etc...you get my drift The look is diff, but components and make up are exactly. Water mngt, food...etc are exactly the same...again you get my drift.

In one tank I keep 14 young Pelv. Taeniatus Moliwe and in the other Nytes. In both tanks I have a breading pair. Each spawned five days apart. In the Nyte tank had 10 survive, 9 males 1 female. In the Moliwe tank had 13. 9 femles 4 males. If everything in the tanks were pretty darn equal why such an opposit squew?

Also the Moliwe group are more peacefull w/each other, feed at the surface, don't hide when they see me. Nytes don't come to the surface to feed, hide more, don't cheer me when they see me. Even the single males don't give each other any peace. Just wondered if it is a general rule that one is more peacefull and social then the other?

g

The Nyete cou

 

[Mike Wise]

It's hard to say. There are many more factors that water and decor that could cause this. Here are a couple of possibles:

A slight electrical leak in heater/filter could affect conductivity and behavior.

Different air pumps can add different pollutants to the tank with air. All it has to be is an unrecognized spill or use of a cleaner closer to one pump than another.

The amount of food not eaten may differ in each tank and affect water values/quality differently.

I guess others can think of other possible factors. Look around the tanks, you might find something. Then again, it might just be 'the luck of the draw'.

 

[tjudy]

P. taeniatus 'Moliwe' and 'Nyete' are, IMO, very different fish. So different that when the dust settles (soon I hope) one or both of those fish may not be P. taeniatus any longer. At one time the Nyete location was not P. taeniatus... here we go! ( I love this taxonomic stuff.)

The first P. taeniatus was described as Pelmatochromis taeniatus (Boulenger, 1901) from fish collected in Nigeria. The original description of the 'krib' from the watersheds north of the town of Kribi, Cameroon (including the Kienke River, which runs right through town and is likely the type locality) was Pelmatochromis kribensis (Boulenger, 1911). Later, the fish south of Kribi (collected in the Lobe River system, which is where Nyete is found) were described as P. kribensis calliptera (Pellegrin, 1929). So the fish from Nigeria and from southern Cameroon were described by the same authority (Boulenger) as being different. And those two types are indeed very different. Aquarists and scientists have been saying that for decades.

The problem that resulting in lumping them all together was made in 1960 by Meinkin, who described the Nigerian form as Pelmatochromis klugei (Meinkein, 1960). At the time there were a lot of fish in Pelmatochromis that were very different (like Haplochromis in Lake Malawi for a long time), and the debate started by Meinkin resulted in the reclassification of the fish in the genus. In the late 60's Pelvicachromis rollofi (van den Audenaerde, 1969) was described, and the author (a lumper...) used the paper to erect the genus Pelvicachromis (good!) and to lump P. taeniatus, P. kribensis, and P. k. calliptera into one species (and since P. taeniatus was the senior name, it was the one they all got). P. klugei is considered a synonym of the original P. taeniatus.

What is P. t. 'Moliwe'? Good question. It has features similar to both the southern Cameroon types and the Nigeria types. I suspect that when Anton Lamboj is done that it will remain P. taeniatus. He MAY erect a new species... but I am no expert. P. t. 'Wouri' may become a new species also. I hope that Anton revalidates P. kribensis and P. k. calliptera.

As to your question... the habitats of Moliwe and Nyete are different. I would not be at all surprised if the sex differentiation range of pH is different for the two fish. I have not seen much of a sex ration difference with Moliwe, though I maintain a very neutral pH as much as possible. I also think that pH is not the only factor. I have had spawns of P. subocellatus for the same pair in the same tank (seemingly chemically stable) have drastically different sex ratios.

Do not change a thing. Let them spawn a few more times and make note of the sex ratios. It will be interesting to see if they change.

 

[peterK]

Ted, thanks for great reading.

 

[georgedv]

Thanks for the info Mike & Ted. Ted, after reading your TFH column, I am caring for all the Pelvs that I have as if they were gold.

g