Tropheus & Petrochromis Published Journal Links

[myjohnson]

Here you will find my collection of articles published by academics that study tropheus and petros in their natural habitat. The fact that most forums are based on the hobby of keeping these fishes there is rarely in dept discussion of how these fishes live in the wild. I have posted this on other forums and got a lot of info from other forums as well.

So here is the list of articles that you guys might find interesting:

1) http://www.pubmedcentral.nih.gov/art...?artid=1634779

"Monogamy in the maternally mouthbrooding Lake Tanganyika cichlid fish Tropheus moorii."

2) http://www.geo.arizona.edu/nyanza/pdf/Gilbert.pdf

"Impact of Sediment Pollution on the Littoral Zone of Lake Tanganyika: A Case Study of Two Cichlid Fish, Petrochromis polyodon and Tropheus brichardi."

Seems like the lake is being effected by the humans that live near the shore, that's a no brainier.

But the most interesting information presented in the study is how the petro and trophs interact with each other while feeding to maximize food intake.

I have notice this to some degree in my tanks. The petro seems to have a herding affect on the trophs. I hypothesize that with stronger lights and more algae growth I might see closer to lake activity. I'll keep you guys updated when I find out.

And if anyone with super high lighting and good algae growth keeping both petros and trophs report there findings that would be great.

Enjoy the read. It's one of the better articles.

3) http://www.wdc-jp.biz/pdf_store/isj/public...0/302/30203.pdf

Division of petro species

Above it a link to an old article my friend sent me. It's written in 1982 when the naming of petros where being workout by the PhD folks.

My friend is working on her PhD on the lake right now but its not for petros so she is not totally up to date.

Summary of article: Has good pictures of how the PhD folks decided for us which petro variant fits into which petro species. Also good table graphs showing the shape and sized of head, lips, fins, etc for each petro species.

If you're a petro nut like me you'll love it!


4) http://behav.zoology.unibe.ch/sysuif/uploa...haviour2005.pdf

Inportance of feeding partterns while mouthbrooding in trophs

Above is a "relative" simple reading of the cost and benefits to feeding while a female tropheus is holding. I do see this activity in my tanks, and I'm sure most of you guys have too.

Coolest info: look over the graphs. All feeding and movement for holding females are factored in and are documented via quantitative method.

5)http://www.pubmedcentral.nih.gov/art...=1560039#bib60

"Colour-assortative mating among populations of Tropheus moorii, a cichlid fish from Lake Tanganyika, East Africa"

Read it over and over and it's been published for a while now. I wonder if the conclusion would still hold true b/c for sure we see cross breeding in our tanks.

Coolest info:

"In June 1998, local fishermen collected about 300 adult individuals of T. moorii from several sites in the southern part of the lake, with the intention of exporting these colourful fishes for the aquarium trade. Owing to the fact that the fishing was carried out without concession, Zambian authorities refused export permits. Instead of returning the fishes to their original habitats, as instructed by the local authorities, the catch was released in a small harbour basin of not more than 200m2 in size in front of the Fisheries Department in Mpulungu, Zambia (L. Mwape 1999, personal communication)."

Summary of article: females are picky. Guess their a lot like humans.

[myjohnson]

6) http://www.africa.kyoto-u.ac.jp/kiroku/asm...%20KAWANABE.pdf

Territioral Behaviour of tropheus

Above is a link to an article about tropheus defending their territory. Nice read for those that want to know how tropheus act in the wild during the daytime vs. night time.

Most interest statement:

"...it is safely concluded that tropheus moorei have their own territories for guaranteeing their feeding place."

"At night, most individuals left their own territories and crowed together under large rocks situating very shallow part along the shore...."

Comments: This was a good read for a number of reasons. First, we see this same thing in our tanks. Second, what's new to me, that I never considered, was how at night the dominant tropheus didn't mind having other fishes around. Third, there was good information on average size of the defended area. Finally, this article also give us another reason why having two rock piles on each side of a 4-6 foot tank works.

7) http://www.geo.arizona.edu/nyanza/pdf/Hintz.pdf

Above is a link to an article about nutrient recycling. "Relatively" simple read.

Most interesting statement:

"Nutrient recycling occurs when nutrients are released into the environment by animals or microbial consumers. Fish-mediated nutrient recycling is an important source of nutrients for primary producers in many aquatic ecosystems, sometimes even exceeding external loading rates (Attayde and Hansson 2001). Consumers release non-assimilated nutrients as liquid waste that is available to primary producers or as feces that is available after further degradation."

In other words, tropheus eat poo from other fishes.

general comments: I don't really think this is a great article compared to some others. Tana Hintz just took 8 fishes and tested what they excreted in a bag. Tested the water and came up with her conclusion.

There are two problems I see with this:

1) Sample of 8 fishes don't mean much.
2) even as normal fish keepers we know that tropheus will not have a constant excretion rate. I see my fishes excreting their food at different times during the day.

However, to her credit she did say more research needs to be done.

8. http://www.africa.kyoto-u.ac.jp/kiroku/asm...ita%20MBOKO.pdf

Aggressive Behaviours of Cichlids Against Larger Heterospecific Intruders

Above is a link to an article that studies aggressive behaviors of fishes in lake tang. The article is a little dated but it's always nice to have some information of what really goes on in the wild.

Summary: Trophs, among other tang. cichlids interact differently between themselves and other species. It seems that size is the determining factor of who's boss when it comes to con-specific species. However, the interaction changes when it's between heterospecific species. The articles concludes that in heterospecific realtionships...SIZE is not the determining factor. That came as a suprise to me!

Personal comments: Never really had the chance to see these type of activity go on with trophs in my tank b/c I keep only one varient of trophs in a tank with no tank mates other than a petro.

Hopefully, someone else that has a community based tropheus tank can comment and see if this activity also happens in their tank.

9) http://www.public.iastate.edu/~dcadams/PDF...oolCichlids.pdf

Equivalent ciclid species from lake Malawi and Tang

Above is a link to an article I had for a while. Don't think it's a great article, but worth the read if you are interested in the evolution of petroschromis sp. found in lake Tang vs. Petrotilapia sp. found in lake Malawi.

Generally comments: I wish they did some DNA testing to see if there is any evolutionary connection. With the evidence of DNA, IMHO, the conclusions would be much stronger. However, I don't want to take away form the simple method of geometric morphometric technique. It's my understanding that Darwin himself used this method to postulate the famous theory found in his book "On the Origin of Species by Means of Natural Selection.

10) http://www.geo.arizona.edu/nyanza/pdf/solomon.pdf

Trophic ecology of the benthic littoral of Lake Tanganyika: the role of grazers in determining algal biomass and productivity

Above is a link about "the role of grazers in determining the standing stock and productivity of communities of primary producers. Lake Tanganyika is a large tropical lake renowned for its biodiversity and endemism across many taxa, including abundant grazing thiarid snails and cichlid fishes."

Basically, it's about snails vs. other algae eating cichlids in lake tang.

Disclaimer: I only read this thing once....which means I understand about 30% of it. Until then I can't form a respectable judgment on it.

[myjohnson]

11) http://www.vub.ac.be/phd/verdediging...200711071a.pdf

Nutrient dynamics and production in the northern Lake Tanganyika

Good read if you are intersted in: "The main objective of this study was to describe and understand the seasonal variations of carbon and nutrient utilization by planktonic organisms in the northern Lake Tanganyika."

really short read.....really more about the chemical make up of lake tang.

Which may or may not apply to tropheus keeping. I personally want my tank to be as close to lake conditions as possible and it really does depend on which sp./variant you have.

It's a short and simple read.....not bad at all really.

12) http://repository.kulib.kyoto-u.ac.jp/dspa.../1/ASM_9_65.pdf

COMPARATIVE OSTEOLOGY OF THE SUSPENSORIAL COMPLEX OF ALGAL-FEEDING CICHLIDS (PISCES, TELEOSTEI) FROM LAKE TANGANYIKA

Above is a link....it's an old article but a decent read.

Topic: "The comparative osteology of the suspensorial complex in 20 species of epilithic
algal feeders from Lake Tanganyika was studied as a means of obtaining fundamental
data for understanding the adaptive radiation in feeding habits of cichlid fishes in the East
African lakes."

Comments: cool comparison between petros, simos, and others jaw structure.

Sorry it's a little old, but any study on petro is hard to find.

13) http://www.aslo.org/lo/toc/vol_26/issue_3/0532.pdf

Primary production and rates of algal growth in Lake Tanganyika

Above is a pdf I had for a while. I got into connect with some friends studying on the lake and they gave me an internet link to it.

It you want to know what's really going on in the lake with seasonal algae growth....it's worth the read.


14) http://www.uni-graz.at/zoowww/person...l/Tropheus.pdf

"Phylogeographic history of the genus Tropheus, a lineage of rock-dwelling cichlid fishes endemic to Lake Tanganyika"

15) http://www.biomedcentral.com/1471-2148/7/137
"Nuclear and mitochondrial data reveal different evolutionary processes in the Lake Tanganyika cichlid genus tropheus."

[J-WS6]

Wow, lots of good data. Thanks for sharing Thai.

[myjohnson]

J,

I had these articles for a while. Posted them on other forums too. Just thought it would be a source for people here on the BOX if they wanted to read this stuff.

I can't understand half of it.

The only person that can fully understand this Ph.D. mumbo jumbo is Mike.

That's when he isn't all boozed up that is....

[cichlid1409]

thanks for these links johnson. just read the first link, although it didn't offer me much new info it was a detailed report and a good read. i hope to read through most of these as i get the time.

[myjohnson]

No problem dude. Just sharing the info. I myself have to sit down and read the articles time and time again. I just don't understand the stuff to well.

All those PhD guys are planing to just confuse us!

[cichlid1409]

2) http://www.geo.arizona.edu/nyanza/pdf/Gilbert.pdf

"Impact of Sediment Pollution on the Littoral Zone of Lake Tanganyika: A Case Study of Two Cichlid Fish, Petrochromis polyodon and Tropheus brichardi."

very interesting , i had heard about how we as hobbyists affect the populations of lake tanginyika but this shows something i had never thought of , even though its obvious if you think about it, urbanization and deforestation for planting crops has seriously affected numbers of these species due to sedimentation of littoral areas.

[myjohnson]

lol, take a step back and read what you just posted out load!

When did you get your PhD?

Read some of the ones about DNA testing and tropheus lineage. You'll be surprise by the historically hybridization of these fishes.

[cichlid1409]

give me time i'm going down the list, geoff if you havn't read these reports get on it. i can't imagine anyone else on the box enjoying them as much as you.

[cichlid1409]

5)http://www.pubmedcentral.nih.gov/art...=1560039#bib60

"Colour-assortative mating among populations of Tropheus moorii, a cichlid fish from Lake Tanganyika, East Africa"

Read it over and over and it's been published for a while now. I wonder if the conclusion would still hold true b/c for sure we see cross breeding in our tanks.

Coolest info:

"In June 1998, local fishermen collected about 300 adult individuals of T. moorii from several sites in the southern part of the lake, with the intention of exporting these colourful fishes for the aquarium trade. Owing to the fact that the fishing was carried out without concession, Zambian authorities refused export permits. Instead of returning the fishes to their original habitats, as instructed by the local authorities, the catch was released in a small harbour basin of not more than 200m2 in size in front of the Fisheries Department in Mpulungu, Zambia (L. Mwape 1999, personal communication)."

Summary of article: females are picky. Guess their a lot like humans.

this report doesn't seem all that conclusive. the fact that for most individuals they could only identify 1 parent leaves a margin for error. since they can only base the other parent on expressed phenotype of the offspring, theres no way to tell if the genotype of the unknown parent is the same or recessive to the known parent. therefore the fry could be heterozygous for a dominant phenotype with two parents from different locations of the lake. more genome mapping is needed for this report but that takes many years. overall its very interesting circumstances which allowed for this study.

[myjohnson]

overall its very interesting circumstances which allowed for this study.

+1. Think about all the other "circumstances" that goes unreported.

My general concern in reading the article is that it might leave a false impression on tropheus keepers that these fishes x-breed less than they actually do. However, it should also be noted that most people are over concerned with hybridization in a tank. Guess the truth is somewhere in the middle.

[cichlid1409]

yeah it seems that we should really only be worried about x-breeding when 2 variants resemble each other closely (which i've heard people say on here) like sp. reds.

[geoff_tropheus]

your my boy Blue!

Thanks Thai for posting these references.

[myjohnson]

No problem bro. I told you months ago I would but I just got around to it cause the Bar was taking up a lot of my time. None the less the articles are posted.