Biomedical Engineering Reference
In-Depth Information
TABLE 8.3
Biochemical Parameters in Sperm and Plasma Fractions of Semen from Nonhuman Primates
Lactic Acid
Citric Acid
Fructose
Species
SF
PF
SF
PF
SF
PF
C. apella
0
4
13
19
79
85
0
563
496
S. sciureus
42
151
3
4
48
14
0.4
1
110
129
E. patas
34
21
194
222
31
52
127
62
18
39
315
274
C. aethiops
20
12
192
196
5
10
122
25
10
16
264
175
M. mulatto
32
30
138
115
2
5
157
86
14
28
753
900
M. fascicularis
36
17
239
88
0
101
65
7
13
299
264
M. arctoides
28
30
183
186
6
9
231
121
0
262
108
T. gelada
10
130
16
168
0
160
P. troglodytes
24
16
160
127
15
24
256
191
10
30
497
363
Sperm fraction (SF): all parameters expressed in mg/100 ml. Plasma fraction (PF): all parameters expressed in mg/100 ml.
Data adapted from
Ackerman and Roussel (1968)
and
Harrison and Lewis (1986)
.
limited, state-of-the-art microanalytical and in vitro tech-
niques should improve methods for analysis, thereby
increasing our knowledge (
Hinton, 1980; Hinton and
Howards, 1982
). The rhesus ejaculate has been noted to
solidify immediately upon expulsion.
Environmental Effects
Nonhuman primates exhibit a broad array of seasonal
patterning of reproduction (
Table 8.1
). Phylogeny appears
to be a poor predictor of these traits. Prosimians are
generally strongly seasonal
e
a number of prosimians,
including the ruffed and mongoose lemurs, show a testic-
ular volume increase as the breeding season approaches,
with maximum size obtained about 1 month prior to the
initiation of breeding. This volume increase has been
calculated to be over 150%; a body weight increase of
about 14% is also observed during this period. Apes are
generally not seasonal breeders. However, the degree of
seasonality in Old World and New World monkeys is
highly variable and not related to phylogeny (see
Saltzman
et al., 2011
). For example, several macaques are seasonal
breeders (M. fuscata, M. mulatta, M. sylvana), whereas
many species will breed all year round (M. arctoides,
M. fascicularis, M. nemestrina, M. radiata).
Two nonhuman primate genera with strongly seasonal
patterns in male reproductive physiology and behavior are
the Central and South American squirrel monkeys (Saimiri)
and the northernmost macaques (Macaca), such as rhesus
macaques and Japanese macaques (M. fuscata). In both
squirrel monkeys and rhesus macaques, males display
a seasonal pattern of T production, with peaks occurring as
the mating season commences. Both squirrel monkey and
macaque males display T-supported characteristics that
arise during the breeding season. Male squirrel monkeys
undergo weight gain (the “fatted male” response (
DuMond,
1968; Lindburg 1987
)) of around 14%, caused largely by
Copulation and Ejaculation
Reviews of male nonhuman primate sexual behavior and its
endocrine control are provided in
Dixson (1998)
and
Saltzman et al. (2011)
. Male nonhuman primates use
a variety of behaviors to initiate sexual interactions (
Dixson,
1998
). Most nonhuman primates display dorso-ventral
mounting postures, typical of most mammals; however,
numerous variations are seen in relation to the nonhuman
primates' varied locomotor styles (e.g. arboreal versus
terrestrial). Nonhuman primates species vary in the number
and duration of intromissions prior to ejaculation (
Dixson,
1998
), from single, brief intromissions (e.g. marmosets) to
single but prolonged intromissions (e.g. stump-tailed
macaque) to multiple, brief mounts (e.g. rhesus macaques),
the most extreme case being the thick-tailed greater galago
(Otolemur crassicaudatus), in which post-ejaculation
intromissions lasting hours suggest the possibility of
a genital lock. Capacitation is a phenomenon affecting the
sperm that normally occurs within the female reproductive
tract and, through enzymatic action, renders the sperm
capable of fertilization (
Dukelow and Yorozu, 1986
). In
most nonhuman primate species studied,
this requires
approximately 2 to 8 hours.
