Edinburgh Napier University

  Studies of wild callitrichids reveal limited data about their complex diets. As
insectivorous primates it is likely that they can digest chitin. Using the
common marmoset, Callithrix jacchus, as a model, this study assessed chitin
digestibility and whether or not a variety of zoo-housed callitrichid species
display a preference for particular insect types. The presence of chitinolytic
microorganisms in the faeces of Goeldi's monkey, Callimico goeldii, was
investigated using both culture-based and molecular techniques and a
preliminary evaluation of the faecal bacterial population was made.
The measurement of faecal acid detergent fibre in C. jacchus showed that
they did digest insect chitin and furthermore Goeldi's monkeys; cotton-topped
tamarins, Saguinus oedipus, Geoffroy's marmosets, Callithrix geoffroyi and
pygmy marmosets, Cebuella pygmaea, showed significant preferences for
particular insect types. The presence of chitinolytic microorganisms in the
faeces of C. goeldii, was confirmed with Cellulosimicrobium spp being among
a number of chitinolytic microorganisms isolated. Using a range of agar
media targeted to specific bacterial genera, Bacteroides, Lactobacillus,
Bifidobacterium, Clostridium and coliforms were found in the faecal samples
and numbers present estimated. As expected the highest count was for total
anaerobes, with Bacteroides and Clostridium species present in high
numbers. Molecular analysis resulted in the isolation of 113 16S rDNA
sequences which matched existing entries in the GenBank database. Eighty
five % of the isolates were matched to clones of unassigned phylotype but
clones from the genera Howardella, Escherichia, Shigella, Prevotella,
Megasphaera and Bifidobacterium were identified.
The evidence resulting from this investigation will inform diet development
and aid in the future health management of callitrichids in captivity.
Additionally, the isolation of novel chitinolytic microorganisms could have
potential industrial applications where the degradation of chitin is of interest.