NEWS107
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moorii,
and
T.polli
).Oneofthe loveliest isun-
doubtedly the
Tropheus
from Kasanga (in
the farsouthofTanzania),whichdoesn'tbe-
longtoanyofthespeciesdescribedtodate.
Nasty fellows?
All
Tropheus
feed on aufwuchs. The word
aufwuchs isGerman inoriginand refers to
the multitude of micro-flora and -fauna
where theyareusuallyseen in largegroups,
although things are far from peaceful in
thesegroups.The fishes are constantlyen-
gaged in territorial squabblesor exhibiting
courtshipbehavior,which itself isn'texactly
all sweetnessand light.It isn'teasy togivea
rational explanationof thishigh inclination
towards aggression, as food is not only in
short supplybut also rather nutrient-poor.
all over the lake, their behavior isquiteob-
viously a successful survival strategy - and
that isall thatmatters.
Constantlyon themove
There is always somethinggoingon in an
aquariumwith
Tropheus.
These fishes are
hectic swimmers.Anddominantmales are
extremelycolorful.Juvenilesand femalesof
Tropheus
sp."Kasanga"arenoticeablydiffer-
entlycolored tomales.While juvenilescon-
tinuetoenjoyasortof immunitybecauseof
their age, the females develop anorder of
rankamongthemselves.Formanyaquarists
thispictureofa lively,verycolorful commu-
nity, inwhich there isconstantlysomething
goingon, is themotive forbecoming invol-
vedwith themaintenanceandbreedingof
Tropheus
in the aquarium. But itmay also
possiblyexplainwhy thehighpotential for
aggression in
Tropheus
hasproved favorable
inthecourseoftheirevolutionaryhistory.As
Tropheus
are so-called agamousmaternal
mouthbrooders. That signifies that males
Thismale is second in theorderof rank.
Juvenilesand femalesareusually striped.
foundonthesurfacesofunderwaterobjects
- inthewildusuallystones,wood,andaqua-
ticplants.Thebulkof the aufwuchs in the
habitat of
Tropheus
consists of small algae.
Tropheus
are foundon sunlit rocky shores,
So it isn'tactuallyverysensible to immedia-
tely invest hard-wonenergy inexhausting
battles.ButNaturedoesn't functionsosimp-
listically. Because
Tropheus
are common-
placecichlidsof therocky littoraland found
and femalesdonot formany long-termpair
bondandthe femalesaloneareresponsible
forbrooding theeggs in theirmouths.
Anattemptatanexplanation
Amale in full color isexhibitingdominance
behavior.He is saying, "I am strong and in-
vincible".Everyothermale isapotential rival
tobedrivenaway.Subordinatemalesexhi-
bitnoticeablyduller colorsor evenassume
female coloration.A female is thuswell ad-
vised to seekout themost colorfulmaleas
amate,ashewillpassongoodgenes.When
a female approaches such an alphamale,
then he interprets this as willingness to
spawn.If,however,the female isnotreadyto
mate, then themalewill see the female as
nomore thanacompetitor for food,and to
bedrivenaway.Females inturn fightamong
themselves forthebest feedingsites,asthey
areprevented from feedingduringthetime
