NONHUMAN PRIMATES:
Taxonomy and Use in Research
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There is disagreement among taxonomists as to
the classification of nonhuman primates.
However, depending on the classification system
used, there are two -- and sometimes three -principal suborders recognized in the order
Primates.
Using Kavanagh’s classification, the prosimians
are of the suborder Strepsirhini, and the simians
are of the suborder Haplorhini.
The Napiers classification add a third suborder,
Tarsioidea, for the group of tiny insectivorous
primates known as the tarsier
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We will primarily use the
Napiers’ system of
classification in this course,
which includes three
suborders, Prosimii,
Tarsioidea, and
Anthropoidea. The
anthropoideans are very
important to use in
research and will be
covered in the most detail.
Primates
Prosimians
Tarsioidea Anthropoidea
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Don't panic over all these suborders,
infraorders and superfamilies! DON'T
memorize this information. This
taxonomic breakdown is intended to give
you an idea of the relationship of the
different primates, nonhuman and human.
Prosimians Suborder Prosimians
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The first of the three
suborders is the
prosimians.
Prosimians, or
strepsirhines, differ
from the simians, or
haplorhines, in
several ways.
Prosimian characteristics
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Prosimians have a wet patch of skin around the nostrils,
which is joined to the upper lip. They have an anatomical
characteristic called a dental “comb” — made up of the
lower incisors, which project forward horizontally and in
parallel, like a comb. They also have a horny structure
under the tongue known as the sublingula, which is used
for cleaning debris off the dental comb. Most of them are
nocturnal and all possess a tapetum lucidum, a
crystalline shield that lies behind the eye’s light-sensitive
retina and reflects light back onto the retina, thus
improving vision under poor light conditions
Prosimians/ Varecia variegata
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This is a photo of a
prosimian, a ruffed lemur
(Varecia variegata) from
Madagascar.
Prosimians rely primarily
on their sense of smell.
They can detect and
interpret smells expertly,
and they leave smell
messages of various
kinds for each other. In
addition to the lemurs,
lorises, galagos, indriids
and aye-ayes are also
prosimians
Tarsioids
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Suborder Tarsioidea
The second suborder is the
tarsioids, which have
characteristics of both the
prosimians and
anthropoiedeans. The
suborder Tarsioidea contains
one family, Tarsiidae. There
are three species of tarsiers,
Tarsius syrichta (Philippines
tarsier), Tarsius bancanus
(Horsfield’s tarsier), and
Tarsius spectrum (spectral
tarsier).
Tarsius syrichta
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Tarsiers have an
average weight of only
120 grams (or 4.25
ounces), and are
nocturnal animals.
Because they are not
heavily used for
research purposes, we
will not focus on the
tarsioids, but move on to
the simians
Simian Suborder Anthropoidea
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We will now move
away from the
prosimians and
tarsioids, and will
be considering the
third and final
suborder,
Anthropoidea,
known as the
simian primates.
Simian characteristics
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Whereas the prosimians (or strepsirhines) have a wet
patch of skin around the nostrils, the simians (or
haplorhines) have hairy skin between the nostrils and
the upper lip.
They do not have a dental comb or sublingula and
most have poor night vision.
Old world
New world
They have a poorly developed sense of smell
compared to prosimians and most are diurnal. Note
the map in the background, indicating that the simians
originate from both the “new world” and the “old world”.
This map will vary as we proceed to discuss simians
from around the globe.
Simians
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The suborder
Anthropoidea is
categorized into
New World monkeys
(of the infraorder
Platyrrhini) and Old
World monkeys and
apes (of the
infraorder
Catarrhini).
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New World monkeys
We will talk in some
detail about the
New World and Old
World families. But
for now, compare
some of the
features of the New
World monkeys
shown on this
image
Cebus albitrons
Saimiri sciureus
Old World monkeys
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with those of these
Old World monkeys.
Erythrocebus patas
Macaca nemestrina
New World monkeys
Infraorder Platyrrhini
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The two families of New World monkeys (infraorder
Platyrrhini) are the Cebidae and the Callitrichidae, both
of which include genera which are quite useful in
biomedical research.
New World monkeys
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New World monkeys,
originating in South
and Central America,
are known as
platyrrhine monkeys
because of their
widely separated
nostrils, which usually
open to the side
having a broad (flat)
nose”
New World characteristics.
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None of this group has cheek pouches or rump
callosities. The thumb is semi-opposable and
the great toe is opposable.
Males of most species have an os penis or
baculum, but it is lacking in Aotus, Ateles, and
Lagothrix. Some New World monkeys are known
to possess color vision and some have
prehensile tails also “a slender bone reinforcing
the penis in some mammals” “adapted for
grasping or seizing”
Family Cebidae
The family Cebidae includes several
genera which are important in biomedical
research:
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Saimiri spp
squirrel monkeys
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Aotus spp
owl monkeys
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Cebus spp
capuchins
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Ateles spp
spider monkeys
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Lagothrix spp woolly monkeys
Squirrel monkeys
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Saimiri sciureus, or
squirrel monkeys,
are small in size,
diurnal, and
arboreal. They
normally have only
one offspring and
males are
polygamous
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They are used in dental,
cancer, vision,
cardiovascular, and
infectious disease
research. They were
recently shown to be
susceptible to
Plasmodium falciparum,
making them extremely
valuable for malaria
research.
Owl monkeys
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The Aotus spp, or
“owl monkeys” –
also known as
douroucouli
monkeys or night
monkeys – are
small, nocturnal and
arboreal.
Owl monkeys/use in research
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Owl monkeys have
long been valuable
models of human
malarias, other
infectious diseases,
and models for vision
research
Capuchins
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Cebus spp, or
capuchins, are
larger than squirrel
and owl monkeys.
Also known as
ringtail monkeys, the
capuchins are
diurnal and both
arboreal and
terrestrial.
Capuchins/use in research & nonresearch use
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They are used in
pharmacologic, infectious
disease, and behavioral
research. These highly
intelligent primates are
tractable; in fact, many
have been used as
“organ-grinder” monkeys.
Recently they have made
valuable contributions as
helping hands for the
physically handicapped.
Spider & woolly monkeys
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Other platyrrhines of the
family Cebidae – such
as Ateles spp, or spider
monkeys, and
Lagothrica spp, or
woolly monkeys – are
used in research. These
platyrrhines are
relatively large, have
prehensile tails, and are
diurnal and arboreal
animals.
Spider & woolly monkeys/use in
research
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Spider monkeys and
woolly monkeys are
used in studies of the
cardiovascular
system and in studies
of infectious diseases.
One particular
species of woolly
monkeys, Lagothrix
lagothrica, is used in
research.
Marmosets & tamarins
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Marmosets
(Callithrix spp) and
tamarins (Saguinus
spp) are from the
family Callitrichidae.
Callitrichids are
small in size, diurnal,
frequently have twin
births, and males
assist in caring for
the young
Marmosets & tamarins/use in
research
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Marmosets and
tamarins are used for
cancer and hepatitis
research, and also for
a variety of other
studies.
Old World monkeys & apes
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We now move along the
taxonomic chart from the
New World (infraorder
Platyrrhini) to the Old
World (Infraorder
Catarrhini). We will be
addressing both the Old
World monkeys (of the
Cercopithecoidea
superfamily) and the Old
World apes (of the
Hominoidea superfamily).
Old World monkeys & apes
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These primates have
catarrhine noses (socalled because their
nostrils are separated
by a narrow nasal
septum) and are hence
from the infraorder
named Catarrhini. The
narrow downward
nostrils of the
catarrhines help
distinguish these Old
World monkeys from
the platyrrhines
Old World characteristics
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Old World monkeys usually
rest in a sitting position and
accordingly are equipped
with ischial callosities, which
are tough pads of cornified
skin located over the bony
prominances of the buttocks.
Ischial callosities are not
present in New World
monkeys, making this feature
an important identifier
Old World characteristics
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Some Old World monkeys are
arboreal or terrestrial, some
both. Scent marking and
smells are of little importance
compared with prosimians or
New World monkeys. They
have nails rather than claws
on all digits, similar to humans
or apes. Their thumbs are
truly opposable. All species
are diurnal. None has a truly
prehensile tail.
Cercopithecidae Family
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The Old World monkeys (superfamily
Cercopitchecoidea) are all represented within the
single family Cercopithecidae. Taxonomically, the
family Cercopithecidae is divided into two distinct
subfamilies: the Colobinae and the Cercopithecinae.
monkeys with tails”
Subfamily Colobinae
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The colobine
monkeys include the
genera Colobus,
Procolobus,
Presbytis, Pygathrix,
Rhinopithecus,
Nasalis, and Simias.
These monkeys are
rarely used, and
generally only in
biological research.
The Old World
colobine monkeys are
leaf-eaters.
Subfamily Cercopithecinae
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Several genera of the Cercopithecinae subfamily are valuable for
biomedical studies. Most of the cercopithecines are omnivorous.
The Old World cercopithecine monkeys include the genera Macaca,
Cercocebus, Papio, Mandrillus, Theropithecus, Cercopithecus,
Miopithecus, Allenopithecus, and Erythrocebus.
Tail length
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Within the
subfamily
Cercopithecinae all
species have tails,
but two groups are
known by common
names as “longtailed” or “shorttailed” monkeys.
Long-tailed monkeys
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“Long-tailed” monkeys include:
Cercopithecus spp-(guenons) Erythrocebus patas-(patas) Cercocebus spp (mangabeys)
Guenons
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The long-tailed
Cercopithecus
includes 20 species
of guenons,
including the African
“green” or
“savannah”
monkeys.
Green monkey
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The African green reproduces prolifically
and is said to be perhaps the world’s most
common species of monkey. Adults weigh
5 - 7 kg, and males are larger than
females. Cercopithecus aethiops (the
African green monkey) naturally occurs in
that part of Africa between the desert
fringe and the forest of subsaharan Africa.
Green monkey/use in research
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African green monkeys are used regularly
for physiological, neurobiological,
immunological, cardiovascular and other
research studies.
Patas
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The second group of
long-tailed monkeys
is the Erythrocebus
patas, or patas
monkeys, also
commonly known as
the red, hussar, or
military monkey
Patas
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Patas are mainly
terrestrial and they range
within the drier, more
open regions of Africa’s
savannahs and semideserts in the subsaharan region. They are
large with females about
7 kg and males over 10
kg. They are used mainly
in infectious disease
research
Mangabeys
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The third long-tailed
cercopithecine monkey
group is the Cercocebus
spp. (or mangabey).
Mangabeys are mildmannered and arboreal,
although some are
arboreal-terrestrial. They
are diurnal central African
forest dwellers.
Mangabeys
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Adult mangabeys
reach a weight of 7 11 kg. Males are
larger than females.
Mangabeys are
valued in biomedical
research for
neurobiological,
cardiovascular and
other studies.
Short-tailed monkeys
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The so-called “short-tailed” monkeys include the several
species of the genus Macaca — that is, the macaques.
Tail length, however, is not a consistent criterion. For
example, within the macaques, tail lengths vary from
quite long as for M. fascicularis (known as the long-tailed
macaque), to short as for M. arctoides (known as the
stump-tailed macaque), to almost absent in M. sylvana
(once, because of the lack of a tail
Macaques
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Macaques, subfamily Cercopithecinae, are
arboreal-terrestrial. They live in habitats varying
from tropical flatlands to frigid mountains, and all
have dominance hierarchies in their social
systems.
The young weigh about 450 g at birth, nurse
approximately a year, mature at around 3-4
years, and live up to about 30 years. They are
large (about 2.5 - 15 kg) as adults
Rhesus & long-tailed/use in research
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Several species of this group
are valuable biomedical
research models. The Rhesus
(Macaca mulatta) and
Cynomolgus also called longtailed macaque or crab-eating
macaque (Macaca fascicularis)
are useful in physiology,
hematology, reproduction,
cardiovascular, infectious
disease, and behavioral
research.
Rhesus & long-tailed/use in research
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They have been used in vaccine
development and drug testing for many
years.
Other macaques/use in research
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Other macaques used in research
include:
Macaca nemistrina (pig-tailed macaque)
•Macaca arctoides (stump-tailed macaque)
Other macaques/use in research
Macaca
radiata, or the bonnet macaque
Macaca nigra, or the Celebes black macaque
Baboons
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The last genus of the
subfamily
Cercopithecinae
which is the Papio, or
baboons. Baboons
were once known as
Cynopithecoids or
“dog-monkeys”
because of their
elongated faces
Baboons
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The Papio spp. live
outside the closedcanopy forests of
Africa except the
deserts and are mainly
terrestrial. Inherently
ferocious, they are
tractable and readily
learn a variety of tasks.
Adults weigh 18 - 30
kg, males larger than
females.
Baboons/characteristics and use in
research
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They travel in troops, and
males form harems of 610 females. Baboons are
valuable research animals
and are used in a variety
of studies in dentistry and
medicine. They have been
useful in immunology,
cardiovascular,
reproduction and
transplantation research.
Hominoidea
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The last catarrhine group
which we will consider is the
Hominoidea. This superfamily
of Old World apes includes
both the lesser apes, the
great apes and the human
primate, man. These animals
are infrequently used in
research because they are
generally either on
threatened or endangered
status. The lesser apes are
classified as the Hylobatidae
family. The great apes are
classified as the Pongidae
family.
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The apes are the
tailless nonhuman
primates native to
Africa and the
southern portions of
Burma, the Malay
peninsula, Indonesia,
Java, Borneo, and
other islands of that
region.
Siamang
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The Hylobatidae Family includes the
gibbons and siamangs
Orangutan
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The Pongidae
Family includes the
orangutans
Gorilla
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Chimpanzees
Chimps are native to
Central Africa. The Pan
spp. are threatened but,
nevertheless, are
important to biomedical
research. Importation is
prohibited and domestic
breeding programs
produce those that are
being used
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Chimpanzees are
used in behavioral,
infectious disease,
and other studies.
They play a
particularly important
role in research on
hepatitis and AIDS.
Adult females weigh
35-45 kg, males 4050 kg.
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Restrictions on importations in the 1970s and concerns
over endangered primate populations led to the
establishment of eight primate centers in the United
States for captive breeding of nonhuman primates. This
has reduced laboratory demand on wild nonhuman
primate populations. The centers also coordinate
increased sharing of animals in studies to decrease the
number of primates needed. The primary species bred
at these centers are rhesus macaques, squirrel monkeys
and chimpanzees
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Approximately 15,000 wild-caught
primates continued to imported into the
United States annually. Most of these are
rhesus, cynomologus, squirrel and owl
monkeys from the Philippines, China and
Peru.
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In December 0f 2000, President Clinton
signed the Chimp Sanctuary Bill
(Cimpanzee Health Improvement,
Maintenance and Protection). This
established a "retirement" facility called
Chimp Haven for chimpanzees no longer
needed for research.
Questions???