Biogeography of Freshwater Fish of Africa - Yves Fermon - June 1/2003
Note Youenn is Yves Fermon
Gas says: we can probally get started eh? Let anyone that comes
in after get caught up on thier own
Youenn says: OK
Youenn says: Lets go now
Gas says: ok....
Quality says: ok
Gas says: i'm going to keep all the speech on for everyone so all
can talk.
Youenn says: First, a small introduction of myself.
Gelo asks: is this big talk about Victorian cichlids?
Gas says: go ahead Yves
Youenn says: My name is Yves Fermon and I have worked mainly on
tropical freshwater fish.
Youenn says: My PhD was on cichids fish of Lake Victoria
Youenn says: I presented it in 1996
Youenn says: I have done field work on African fish in both the west
and east sections of the continent
Gelo congratulates Yves
Youenn says: Recently, I have started to work on French Guiana fish
Youenn says: I am actually based at The Museum national d'Histoire
naturelle in Paris
Youenn says: I will talk today on some aspects of biogeography of
freshwater fish of Africa
Youenn says: just few words before starting from Gas.
Gelo has thought: "serious guy", but nothing has told
Gas says: great
Gas says: I just wanted to say what an honor and pleasure it is
that you have agreed to share a bit of your knowlege with us today
Gas says: on behalf of everyone...many thanks
Gas says: there are graphics with this presentation that if you
want to see will have to have a browser opened
TheJerkyMan asks: ?
Gas says: I believe it is optimized for explorer
Gas says: here is the URL:
Gas says: http://www.africancichlids.net/yves/
Gas asks: am i correct here Yves?
Youenn says: I think so
Gelo checks URL
TheJerkyMan says: Got it
Gas asks: is everyone able to do this?
TheJerkyMan says: I've got it thank's
Seanf says: I got it
Gas says: good stuff
Hdreau says: no but it's not a problem (i don't use IE) but i got
the images
Gas asks: you find it Gelo?
Gas says: sorry Herve
Gelo says: yes
Gas asks: everyone ok so far?
Youenn says: yes lol
Gas says: I'll turn the floor over to Yves now, and once again,
thank you for taking the time to do this today.
Gelo says: i attentively study it
Youenn says: ok. Its me to thank you for taking the time to read what I am
writing. Yopu are welcome
Gelo says: to read and to read, cool
Youenn says: Just a few things: 1. I am French and not particularly
familiar with the English language
Gas says: your english is better than my french :)
Youenn says: 2. I had a break down of my new computer few days ago.
So I will go slower
Youenn says: Lets go to the first slide
Gas says: ok
TheJerkyMan says: ok
Youenn says: You can read here some of numbers concerning species of
known fish.
Youenn says: 40% of the total known species are from freshwater
Youenn says: and freshwater occupies 2% to 4 % of the earth's surface.
Youenn says: so biodiversity is globally greater in freshwater
Youenn says: from this, quite 1/3 of are known species are from Africa
Youenn says: mainly, from the Greats Lakes
Youenn says: lets go on thenext slide
Gas says: #3
Youenn says: Two factors are important in explaining biogeography.
Youenn asks: First, what is biogeography?
Youenn says: Biogeography is simply the study of the distribution of
species and the relationships betwwen different geographical area
Youenn says: By the way, we may reconstruct the history of links and
relationships between areas
Youenn says: for aquatic animals: 2 factors
Youenn says: morphology of the basins and tectonic or erosion factors
Youenn says: One good examples is the creation of Lake Victoria
Gas cheers.
Youenn says: with the upsurge of the mountains the course of the rivers change.
Youenn says: and different basins which were previously connected, have
been disconnectd
Youenn says: the second factors is the hydric balance
Youenn says: that means how much water come in and out in an hydric
system
Youenn says: still on Lake Victoria, the level have change several
times and the lake was completely dry quite 12000 years ago
Youenn says: so some species have been isolated probably in some
residual lakes and have evolved separately
Thefishdaddy is entering FishRoom!
Youenn says: lets go on the 3rd one
Gas says: #4
Youenn asks: everybody is ok?
MLD says: Yes
TheJerkyMan says: yes I'm helping The Fishdaddy
Gas says: ok here...we are on "how the fish scattered"
Monodactylus says: yep
Youenn says: Ok. As you know, not all fish like to be out of
water
Youenn asks: how they can spread?
Youenn says: first, when, at one moment, there is communication
between basins
Youenn says: For example, the fish fauna of the Chad basin and the
Nile are very closely related
Youenn says: And some fish have colonised these two basins
Youenn says: then, the sea level.
Youenn says: With the rise of the sea level, some island have been
separated from the mainland
LisaB is entering FishRoom!
Youenn says: And you can see similar fauna. It is the case of the
Fernando Pool
Youenn says: then, eggs can be transported by mammals and birds. Some
have a glue-like substance and they can be attach to a bird or mammals
Youenn says: The last case which may separate and block the fish is
the presence of natural barriers
Youenn says: Falls are the best exemples
Youenn says: nextslide
Youenn says: in French :D
Gas says: #5
Youenn says: you can see here a map showing the main great
biogeographical region of fish fauna in Africa
Youenn says: This map have been made according the affinity of the
fish fauna from the differents basins
Thefishdaddy appears in the room.
Youenn says: It is clear that the Nilo soudanien region is the most
important one
Youenn says: One small point. The lake Victoria fauna is more or less
related to the Nile fauna
Youenn says: But have been quite clearly separated
Gelo says: i don't see the map :(
Youenn says: Tanganyika fauna is related to the Congo/Zaire basins
Youenn says: And Lake Malawi from the Zambezis basins
MLD says: 2 minutes for appearing of map
Youenn says: OK I can wait
Gelo says: ohhoo
Woot is entering FishRoom!
Woot appears in the room.
TheJerkyMan says: were are we had a couple folks I needed to help get
into the room
Gelo says: don't wait
TheJerkyMan asks: can you send the URL again for those that may have
missed it and say what slide or area of the presentation we are at?
Gas says: http://www.africancichlids.net/yves/
Gas says: slide 5
TheJerkyMan says: thanks ;-)
TheJerkyMan says: Ok I'm set ;-)
Youenn says: ok lets go to the next one
Gas says: #6
Youenn says: On this slide you will see a table with some fish and
the fossils recorded
Youenn says: The oldest ones belongs to Polypterus and Protopterus
Youenn says: These fish are wide spread in all Africa
Youenn says: and show some primitive characteristics
Youenn says: Protopterus belongs to Dipneust family of lung fish
Youenn says: you can find species from this family in Australia and
also in South America
Gelo chews hyrodactylus
Youenn says: Polypterus is now only from Africa
Youenn says: but some fossils have been recorded in South America
recently
Youenn says: You can see that the oldest family after these two are
characoids
Youenn says: Nile perch (Lates) was found also in old times
Youenn says: It is true that Nile Perch is really widely spread
Youenn says: lets go to the next one
Gas says: #7
TheJerkyMan says: Slide #7
Youenn says: Here some text related to what we know actually
Youenn says: 20MY ago, no geographical barriers
Youenn says: And we still find some species widely spread all over
Africa quite like the cichlids Tilapia zillii and Sarotherodon galileus
Gas asks: MY=million years Yves?
Youenn exclaims: These two species are know from west Africa to Syria!
Youenn says: yes million years
Youenn says: Hepsetus odoe or African Pike is also known to have a
very wide distribution
Youenn says: Then, nearby 15 MY, tectonics events and formation of
the Rift Valley which Africa in two major parts
Thefishdaddy says: I'm still here
Youenn says: Then on the quaterly period several climatic events
occured bringing high instability to the climate
Youenn says: Several expensions and regression of basins with
connection and disconnection
Youenn says: by the way, colonisation and extinction of species
is what occured in the Lake Victoria basins
Gas nods his head in understanding.
Youenn asks: problems?
Gas says: so far so good here
Youenn says: on the next slide, an example of what have been found
with invintories made
BruceW is entering FishRoom!
TheJerkyMan asks: slide #8
Youenn says: biogeographical pattern for north tropical africa
TheJerkyMan says: got it ;-)
Youenn says: 3 major regions have been found
Youenn says: nilo soudanien the larger one
Youenn says: upper guinea
Youenn says: and lower guinea
Youenn says: two main fish assemblages:
Youenn says: the first one covers all the nilo soudanian province
with species which are completely absent from the congo/zaire basin
Youenn says: the second one are the lower and upper guinea regions,
with fish related to the congo basins
Youenn exclaims: If you look to the map. Its quite surprising!
Youenn says: for the upper guinea
Youenn says: thats means that at one time there was a relationship between
basins of these two region at one point
Youenn says: lets go on the next one
Gas says: #9
Gelo says: it is very interesting lecture, but i should leave you.
Thank you Yves
Youenn says: Its is just a table to show the number of species by
family per basin a little bit. You can see that some families are just
known from a few basins like nandidae
Youenn says: some are just known from a part of Africa
Youenn says: Osteoglossidae are just known in the western part
Discus appears in the room.
Youenn says: So one minute for you to look at it
Youenn says: I am making a coffee lol
Gas says: lots of mormydis
Thefishdaddy says: i didn't know there's a lot osf species of
mochackdae
Youenn says: surprising no? lol
Gas says: lots must be undescribed
Youenn says: ok lets go one coffe ready :D
Youenn asks: ok?
TheJerkyMan says: Ok ;-)
Hdreau says: ok
Gas says: ok here
Discus says: ready
Youenn says: for the next slide, just for all of you, map of lakes
some numbers of fish recorded by families in lakes
Gas says: #10
Youenn says: but DESCRIBED species
Gas grins.
Youenn says: its is the most diverse
Youenn says: see also that in Lake Turkana some families, typically
nilotic, are only found there and not in other lakes
Youenn says: like Gymnarchus
Thefishdaddy says: how big is lake kivu; it only has a few species
of fish
Youenn says: So, finally, Tanganiyka lake is the most interesting ;)
Youenn asks: no?
Hdreau says: yes
Youenn says: then, lake Turkana (Angel)
Youenn says: ok
TheJerkyMan asks: size of lake Kivu?
Gas says: Turkana and Tanganyika are the most diverse in terms of
different families
Thefishdaddy says: the volcanic eruption in african , did it affect
the fish fauna near it
Gas says: Kivu is ruled by cichlids :)
Youenn says: now, I will give you some exemples of fish distrubition. Ok,
lets go on
Youenn says: I show you now some examples
Youenn says: First on all Africa scale
Gas says: #11
Youenn says: This example concerns Alestiidae (Characidae) fish of the
genus Brycinus
Youenn says: 4 species are very closely related
Youenn says: What is really interesting is to see that B. abeli
described as a species, is at the margin of the repartition of t B. imberi
Youenn asks: Are they really distinct species?
Youenn says: two
Youenn says: In fact, probably yes, because B. abeli is known from
the forest area and differs morphologically from B. imberi
Youenn says: But they were probably once a single species
Youenn says: The same for B. carolinae caught only in guinean coastal
basin
Youenn says: And you can see that the distribution of B. imberi and
it's related to species B. nigricauda
Youenn says: In nilo soudanian basins, not the sames species
Youenn says: lets go on
Gas says: #12
Youenn says: Here is an example of morhological cline in north tropical
africa
Youenn says: Brycinus macrolepidotus
Youenn says: You can see in this tree, which show the relation
between fish collected in different basins that in fact, you have two species
described: B. rutilus and B. macrolepidotus
Youenn says: but they are the same.
Gas asks: will these fish interbreed?
Youenn says: It's just a morphological cline
Youenn says: no because they come from different basins
Youenn says: and you can see that other species are different but
occured in the same basins investigated
Youenn says: lets go on
Gas says: #13
Youenn says: here, still a characoid Alestes baremoze
Youenn says: here are the number of soft ray and the number of scales on
the lateral line according different basin for the same species
Youenn asks: interesting no?
Youenn says: on the left, Cote d'ivoire basins
Gas says: yes
Youenn says: in the middle west african basins nilotic
Youenn says: and right up nile basins
MLD says: a lot
Youenn says: but all these fish belongs to the same species
Youenn says: and in the past, authors have decided to give different
sub-species
Youenn says: on the next slide
Gas says: #14
Gas says: I mean 15
Youenn says: see the difference in the anal fin branched ray, the
number of vertebrae and the maximum length from west to east basins
Youenn says: this is the cause of a non mixed population and separated
basins. But also with gentics, they belongs to the same species
Youenn says: on the next one, the same sclae with another species,
Youenn says: elephant fish, very nice and cute
Youenn says: Petrocephalus bovei
Youenn says: And here on the same basin
Youenn says: the Niger
Youenn says: see the differences in dorsal fin rays and anal fin rays
Youenn says: on the SAME RIVER
Youenn says: that means that you have different populations along the
Niger which do not mix for different reasons
Youenn says: One of these may be the spawning area
Youenn says: these fish spawn in small inondated area in rainy season
Youenn says: and they don't make large migrations
Youenn says: So, after a while, some morphological patterns may appear
Youenn says: or phenotype
Youenn says: phenotype is "what is the expression of genes"
Hdreau asks: is it true speciation ?
Gas asks: isolated populations?
Youenn says: yes probably isolated populations
Youenn says: another example, in a small pretty barb
Youenn says: Barbus bynni
Youenn says: here, the differences in scale
Youenn says: and 2 subspecies
Youenn says: 1 from the Niger systems
Youenn says: the other on coastal ghanean basins
Youenn says: finally on a really small geogarphical scale which may
be of more interest to you
Youenn says: lake victoria cichlids...
Gas says: now were talking :)
Gas says: #17
Youenn says: no comment
Youenn says: I am tired now (angel)
Gas laughs.
Youenn says: on the map you can see 3 islands
Youenn says: Gabamela on the east north part of the Mwanza Gulf
Youenn says: Hippo island west nort part
Youenn says: and Python east south part
Youenn says: I have worked on the morphology of four species from these
3 islands
Youenn says: see next slide
Gas says: #18
Youenn says: on the upper graph is the result obtained with the body
shape
Youenn says: on the lower graph with only the head
Youenn says: you see clearly that all black points are on the left
Youenn says: black points are fish from all species collected at Hippo
island
Gas asks: what species of fish are these?
Gas says: I see one is a P. nyererei but can't make out the others
JLW transports into the room.
JLW says: Holy Fishroomer's, Batman....
Youenn says: that means that there is more differences in the
morphology of the head between fish from the SAME species occuring in different
islands then fish from DIFFERNT species occuring on the same island.. and
in
fact the fish from west and east parts of the Mwanza gulf are morphologically
different
Hdreau says: rufocaudalis greenwoodi and another
Youenn asks: does everybody has understand?
BruceW asks: and the thinking on this is?
Hdreau asks: if it's concern only the head is it linked to feeding ?
MLD says: yes, approximatly ... :o
Gas asks: so locale can make a population of fish, of differening
species, have
simular metamorphic charestics?
Youenn says: its link to the thinking is simple, here you have
probably the results of convergence morphologically adaptation to one kind
of
biotope
Youenn says: yes gas
BruceW asks: it comes down to the defination of speciation utilized,
no?
Youenn says: but the problem, is that more or less several of these
characteristics are used to separate species
Youenn says: ...
Gas says: different species occupy the same niche
and develope
simular feeding adaptations
Youenn says: not only
Gas says: and develope similar feeding adaptations
Youenn says: no
Hdreau asks: but feeding adaptation are another set of characters
used to separate species no ?
Youenn says: but they are under the same external constraints
Discus says: same foods, same housing , same breeding
characteristics= similar appearance
Youenn asks: and what do you think about fish of the same species on
other islands?
Youenn says: ok lets go finish
Gas says: ok
Youenn says: then start discussion
Discus says: i would expect other similarities
Discus says: ok
Youenn says: One slide which is not here
Gas says: uhoh
Youenn says: is just a work that I have done during my thesis
Gas hangs his head
Youenn says: on Pundamilia nyererei
Youenn says: Fish from the same islands, caught in two catches show
in fact 3 main types
Youenn says: morphotypes
Youenn says: one for females and young males
Youenn says: one for big males with a bump and one for males without
bump
Youenn says: teeth where different for all three groups
Youenn says: and feedings also
Youenn says: so.. several morphotypes depending of the age, social
status and way of live for fishes from the same species and same populations
Youenn asks: interesting no?
BruceW says: yes
Youenn exclaims: in fact, big mess, I told you!!!!!
Gas says: very...most excellent
Hdreau says: yes
BruceW says: makes it more fun ;)
Youenn says: thanks for all
Hdreau claps with enthusisam.
Gas asks: thanks a lot Yves, it was great...would you be able to
take a couple questions?
Gas cheers.
Youenn says: depends
Discus says: greg has an article i wrote for his site on the same
thing in social scale of neolamprologus brichardi
Youenn asks: in french?
Discus says: and thank you very much for your time,
JLW exclaims: Je parles francais, mais pas bien!
Discus says: my apologies for being late
Seanf says: Thanks it was very interesting
TheJerkyMan says: yes thank you Yves
Youenn says: thanks a lot
Youenn says: JLW
Youenn says: thanks
Gas asks: when are you going back to Victoria Yves?
Youenn says: do you have money for me? lol
Youenn says: yes JLW
You fall to the ground and roll over laughing.
JLW grins.
Discus says: on a serious note i for one would donate
Youenn says: no
Discus says: much is being lost while the world fights its turf wars
Youenn says: yes
Youenn asks: no question?
Hdreau says: too many
Discus says: a debate we had a few months ago in here, would you say
that these geographic variants represent independant species
Gas exclaims: we need to go find more of those blue nyererei!
Youenn says: just one remark;
Youenn asks: do you know understand why I always insist in the fact
that geographical location of the strains is so important?
JLW says: We get the same problem with Goodeides.
Youenn says: yes I know
JLW says: People mix a lot of populations, and wind up really
screwing up the gene
pool... true of any live bearer, I guess -- look at
Endlers. I've
seen strains so polluted by standard Guppies that they're not
even Endler's anymore.
Youenn says: yes
JLW says: Orangethroated Darters are another good example -- people
have been tossing
them around for so long, and as we look more and more closely
at them, we find there
are actually about 15 species of Orangethroated Darter.
Discus says: i do, and in some cases i would say that the differences
are divergent and therfore represent species separate from their near cousins
Youenn says: The main problem in quick speard and plastic species is
to know where we can put the limit of what is a species
Discus says: with orangethroats the only way to know you have one
species is catch them in the wild and they are controlled in many areas
BruceW says: exactly
Seanf says: it all comes down to how you decide to classify a fish
species
BruceW says: what guidelines does ones go by? ;)
Gas says: the question of the ages Sean
JLW says: Lots and lots of species will cross breed, too. That
defies the definition
of species, in some books.
Youenn says: yes
Hdreau asks: crossbred in natural condition ?
Seanf says: I know in the case of many of the new South American
apisto
species that are being brought in they are being split into many
different
species based on slight differences in morphology
Discus says: technicly a bantam rooster can breed with an ostrich,
are they one species
Gas says: personally i feel that there (in the defination of the
word) are many fewer
species in lake victoria that reported. There is so much
genetic closeness
that hasn't yet evolved to diversify, that we are dealing
with subspecies of
many fish at best
MLD says: bye all ;)
JLW says: That's true of most of the African Lakes.
Youenn says: yes but genetic is only on technic of separating species
and good markers are just now starting to be found
Seanf says: I would agree that many of these fish will eventually
evolve
into different species but it is still in the early stages
Youenn says: ecological differences may be found
Gas says: percicsely
Youenn says: behaviour differences may be found
JLW says: Of course, if you're a collector, and you find some species
of fish with an extra
dot or something on it, and decide to describe it as
Pseudotropheus my-very-own-us...
you can say you're the only distributor of it,
and make good bucks.
Youenn says: yes
Seanf says: Of course and hobbyists will line up to buy it
JLW says: That's really clodded up things.
JLW says: Happens with other species, as well.
Gas says: at the same time, I guess that's why we have to be so
careful about locales
JLW says: There's a company out there that markets Cyanobacteria
pills, they're the
only distributor of this species of Cyanobacteria -- even
though its identical
to most Anabaena... but its found only in their lake.
Hdreau says: or tell it's a geographical variety from a unknown
village very near a known locality