If colour is disregarded, the juveniles of each species can be seen to have an identical V-shaped marking along the
sides of the neck. From left:
V. beccarii, V. boehmei, V. bogerti, V. keithhornei, V. kordensis, V. macraei, V. prasinus, V. reisingeri.
However, more interesting is the fact that
V. kordensis and V. bogerti also share a very close
relationship, despite the island of Biak being
separated by a very deep strait from New Guinea
and that the D'Entrecasteaux Islands are more than
1,000 kilometres to the east. In this case, a gene
exchange is rather unlikely, and there is no
conclusive explanation for the close phylogenetic
relationship between the two species. In addition, the
study found that V. prasinus and V. reisingeri are
genetically almost identical, although there are
visible differences in colour, pholidosis and
morphometrics.
It should be noted that although this study has
demonstrated a very close relationship between
the members of the V. prasinus group, only one
DNA fragment was examined and an
investigation of other gene fragments might yield
distinctive results.
Discussion.
All species of the V. prasinus complex are very
similar, both phenotypically and in terms of life-
style. They inhabit the upper regions of trees and
have an elongated body and long limbs with five
toes, armed with strong, curved claws. All
species also possess a true prehensile tail, which
is actively used for security when climbing
through the treetops. The basic colour of all
species is black. Some species have lighter hues
(e.g. green for V. prasinus and V. kordensis, yellow
for V. reisingeri and blue for V. macraei), whilst in
V. keithhornei a slightly grey pattern prevails.
The remaining species (V. beccarii, V. bogerti and V.
boehmei) are dominated by black, with occasional
yellow or reddish scales as a pattern. However, if
one looks at the juveniles of each species and
disregards the colours, an identical V-shaped
marking formed by lighter scales can be clearly seen
along the sides of the neck (see diagram). Only
when the colours are added can the juveniles be
assigned to species. In some species, these patterns
or markings disappear with age, especially
V. beccarii and V. bogerti, in which older animals
display a uniformly black colouration.
‘ V. kordensis and V. bogerti
share a very close relationship,
despite gene exchange being
rather unlikely.’
Even within the species V. prasinus, the range of
which extends to the whole of New Guinea, there
could be genetic differences. This huge island is