NEWS102
13
Tyttocharax tambopatensis
, female
Twocompetingmalesof
Tyttocharaxtambopatensis
.
The precise biological significance remains
unknown to thepresentday,but it isknown
that the substances releasedplay some role
or other in breeding, as only the males
possess thesecaudalglands.
We know a certain amount more: these
tetras practice internal fertilization. The
femalesareable to lay fertilizedeggseven in
the absenceof amale.And that is precisely
what Roloff observed: the females of the
then still nameless dwarf characin, which
grows to only around 2 cm long, laid their
eggson theundersidesof leaves,something
withwhichhewasalready familiar from the
subfamilyGlandulocaudinae,asthisgroupof
tetras were all classified in Roloff’s and
Ladiges’day; nowadays two subfamilies are
recognized, the Glandulocaudinae and the
Stevardiinae. Both belong to the family
Characidae.
Tyttocharax
The genus
Microbrycon
, to which Ladiges
originally assigned the new dwarf tetra, is
now regardedas a synonymof
Pterobrycon
,
another genus of tetras with tail glands, in
whichmales have two enlarged, spoon-like
bodyscaleswithwhich theymaneuver their
sperm into the female via an acrobatic
performance.
The genus
Tyttocharax
was erected in 1913
byFowler for hisnew species
T.madeirae
. In
1958Boehlkedescribed two further species
inthegenus,
T.atopodus
and
T.rhinodus
,both
from Peru,which are today assigned to the
genus
Scopaeocharax
.And finally,Weitzman
&Ortegadescribedwhat iscurrently the last
Tyttocharax
species,
Tyttocharax
tambopatensis
, in1995.
The three currently still valid species
remaining
in
Tyttocharax
can
be
distinguished relatively easily using the
followingkey:
1a.Adipose finpresent...2
1b.Adipose finabsent.…..
T.tambopatensis
2a.Unpaired fins transparentorwithawhite
edge…...
T.cochui
2b. Unpaired fins with darkmarkings.…..
T.
madeirae
All three species are imported occasionally,
andthosepicturedherewereall importedto
Germany by Aquarium Glaser in 2011.
Because they look rather similar – they are,
after all, tinyandconstantlymovingaround,
so that you need either a very well lit
aquariumor a photo inorder tobe able to
see the differences – they are sometimes
importedmixed together,at least in thecase
of
T. cochui
and
T. tambopatensis
, although
the speciesdon’toccur together in thewild.
Themixing takesplaceat theexporter’s. It is
a real chore for the importer to sort the two
speciesoutagain.
Tyttocharax intheaquarium
Despite their small size – as already
