Stomach Fermentation in East African Colobus Monkeys in Their Natural State

Abstract

The microbial fermentation in the stomachs of two monkeys, Colobus polykomos , collected in Kenya, was studied. The gas accumulated within the stomach contained H 2 but no CH 4 . Volatile fatty acid concentrations were high, but accumulated acid prevented determination of the fermentation rate in untreated, incubated stomach contents. Upon addition of bicarbonate, a very rapid rate could be demonstrated. Some D- and L-lactate were in the stomach contents. Starchy seeds or fruits rather than leaves appeared to have been consumed. Microscopically, the most prominent microorganisms seen were large, very refringent cocci, possibly Sarcina ventriculi , and various smaller cocci and rods. The 28 cultured strains of bacteria included 14 Staphylococcus , 2 Streptococcus , 10 Propionibacterium , and 2 Peptostreptococcus . The culture count constituted 10 to 20% of the direct count. No protozoa or cellulolytic bacteria were found.

Primate Taxonomy: Inflation or Real?

“…But the legacy of Schwarz's taxonomic arrangement was long-lasting. More than 40 years later, Ohwaki et al (1974) studied microbial fermentation in a population of leaf-eating black-and-white colobus, which they designated Colobus polykomos-but their specimens were from Mount Kenya and therefore belong to the species which by this time most primatologists were recognizing as Colobus guereza. The real Colobus polykomos, at the opposite end of Africa, turns out to be more of a seed eater.…”

“…The real Colobus polykomos, at the opposite end of Africa, turns out to be more of a seed eater. Literature databases have presumably nonetheless been listing the species studied by Ohwaki et al (1974) under the name C. polykomos, the species they thought they were studying, and one can envisage a variety of resulting confusions [for example, other physiologists scratching their heads uncomprehendingly at discrepancies between their own findings on the real C. polykomos and those reported by Ohwaki et al (1974)]. Taxonomic lumping, in such a case, has the potential to seriously mislead nonspecialists.…”

“…Primate taxonomy has been experiencing a revolution. The leading primatologists of the twentieth century, John and Prue Napier, in their 1967 compilation (Napier & Napier 1967), recognized 176 species of what we now regard as primates (exclusive of Homo sapiens; note that they also included the treeshrews, which we do not now regard as primates). The most recent compilation listed 376 species (Wilson & Reeder 2005).…”