NEWS105
16
Lexicon
Harlequin rasboras
Trigonostigmameans "triangle spot".
heteromorphameans "of different
form "
Rasbora: from the local Bengal name
for oneof the species.
hengeli:named inhonor of J.von
Hengel,aDutchornamental-fish
importer.
espei:named inhonor ofH.Espe,a
Germanornamental-fish importer.
somphongsi:named inhonor of the
Thai ornamental-fishexporter
Somphongs
exporteur Somphongs
Deep redvariant of
T.espei
,male
The‘
heteromorpha’
partof thename refers
to the different shape of the body when
compared to other rasboras, the vast
majority of which are more or less
streamlined – something that the
harlequin is definitely not. In 1999,
though,MauriceKottelat andK.E.Witte re-
named thegenus,
Trigonostigma
,which is
probably more descriptive, as it refers to
the triangular dark blue patch so
characteristicof the species.
They say that familiaritybreedscontempt,
but this does not apply to the harlequin,
which is stillmuch sought after.There are
many reasons for this, including itseaseof
maintenance.
In its nativewaters of Indonesia,Malaysia,
Singapore and Thailand, the harlequin
inhabits soft, slightly acid, dimly-
illuminated forest streams. However,
within thehome aquarium, it can tolerate
a wider range of conditions, something
that is likely tobe,at leastpartly, the result
of decades of captive commercial
breeding. An approximate pH range of
5.5-7.5 and a hardness range of 20-
215ppm will suit this 5-cm fish, as will
temperaturesbetween22-28oC.A layerof
floating plants, plenty of submerged
vegetation and a dark substratum will
help show off the attractive coloration to
best effect.
Food-wise, harlequins will accept a wide-
ranging diet. Nonetheless, the natural
predatory habits of the species should
also be taken into account, with small
frozen foods, as well as small livefoods,
beingprovided.
fish, but also one of the oldest in the
aquarium hobby. It was first been
introduced into Europe (Germany) way
back in 1906, just two years after it was
originally named
Rasbora heteromorpha
by G. Duncker in a paper published in a
zoological publication of the Naturhis-
torischenMuseumofHamburg.
Deep redvariant of
T.espei
, female
Trigonostigmahengeli
, theGlowlight Rasbora.
Orangevariant of
Trigonostigmaespei
