Publication2 med aquascape Publication1cs complete | Page 86

By Willem Heijns
The male guarding free swimmers
A. centrarchus is the type species of the genus Ar-
chocentrus as Gill (1877) described it. Archocen-
trus contains two groups.The first group consists
of A. centrarchus, A. spinosissimus and the enig-
matic A. immaculatus. The second group compris-
es A. nigrofasciatus, A. spilurus, A. septemfascia-
tus, A. sajica and A. nanoluteus (the “yellow
dwarf”).
The main difference between the two groups is
formed by the superterminal (lower jaw longer
than upper jaw) mouth of the first group, whereas
the second group (nigrofasciatus and the like) has
jaws of equal length. A second characteristic of the
group is the high number of anal spines (X-XI). The
species names centrarchus and spinosissimus
clearly refer to that fact. But there is another spe-
cies with a name referring to a high number of
anal spines. I am talking about the species known
as Herotilapia multispinosa here. This species
shows a lot of resemblance with A. centrarchus.
The pictures of The pictures of both species in
breeding colours are proof of this resemblance.
A. centrarchus and H. multispinosa are believed
to be very closely related to each other and to A.
spinosissimus, meaning that they share a com-
mon ancestor (Bussing, 1976). The origin of these
three species is thought to have been caused by
vicariant events separating the western part of
the old Nuclear Central America (México and
Guatemala), the eastern part of the same area
(Honduras and Nicaragua) and the Talamancan
area (Costa Rica), home of A. spinosissimus, H.
multispinosa and A. centrarchus respectively. In
fact, I think that Herotilapia multispinosa really
belongs to the genus Archocentrus. This is re-
markable because H. multispinosa was placed in a
separate genus on the basis of it’s dentition.
Herotilapia has tricuspid teeth, whereas all basis
of it’s dentition. Herotilapia has tricuspid teeth,
whereas all Archocentrus-species have uni- or bi-
cuspid teeth. Perhaps dentition isn’t that im-
portant as a character as has been thought for a
long time. A behavioural treat supporting the
close relationship is formed by the fact that all
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