The Testis of the African Elephant (Loxodonta Africana)

Ow, Johnson; Io, Buss

doi:10.1530/jrf.0.0130023

Cited by 11 publications

(6 citation statements)

References 4 publications

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“…The major features of the cells comprising the seminiferous epithelium and interstitium corre¬ sponded closely to published descriptions of these cells in other mammals (Johnson & Buss, 1967a;Onstad, 1967 ;Ortavant, Courot & Hochereau, 1969 Fig. 2): the characteristics of these cells and the diameter of the fully developed tubule (about 200 µ ) were similar to those described for other mammals.…”

Section: Histologysupporting

confidence: 85%

“…1, Fig. 3), measuring 4-5 ± 0-1 µ in diameter, could be recognized by the adherence of the chromatin material to the nuclear membrane, as in other mammals, but this material was not as 'beaded' as that found in Rattus norvegicus (Roosen-Runge & Giesel, 1950) and in the African ele¬ phant, Loxodonta africana (Johnson & Buss, 1967a Fig. 3).…”

Section: Histologymentioning

confidence: 84%

“…The relationship of (a) testicular weight, (b) epididymal weight and (c) seminiferous tubule diameter to age in giraffes. (Skinner, Scorer & Millar, 1975) and elephant (Johnson & Buss, 1967b;Hanks, 1972). The relation¬ ships between testicular and epididymal growth with age, and the expansion of the seminiferous tubules are shown in Text-figs 2(a), 2(b) and 2(c) respectively.…”

Section: Sexual Developmentmentioning

confidence: 99%

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The development of the reproductive organs of the male giraffe, Giraffa camelopardalis

Hall-Martin¹,

Skinner²,

Hopkins³

1978

Reproduction

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Summary. The reproductive organs of the male giraffe differ little in morphology and histology from those of other ungulates. There is some indication that gonadal hypertrophy occurs in late fetal life. Spermatogenesis begins at 3\p=n-\4 years of age and coincides with a rapid increase of testicular weight and seminiferous tubule diameter. In the fetal testis the main hormone is androstenedione (2\m=.\73\g=m\g/g) but in adult testes testosterone is predominant (<10\m=.\08\g=m\g/g) and \ g=D\ \ m=' \ testosterone may also be present.

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Section: Histologysupporting

confidence: 85%

Section: Histologymentioning

confidence: 84%

Section: Sexual Developmentmentioning

confidence: 99%

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The development of the reproductive organs of the male giraffe, Giraffa camelopardalis

Hall-Martin¹,

Skinner²,

Hopkins³

1978

Reproduction

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“…Likewise, season has no apparent influence on reproductive activity in the male. Johnson (1963) and Johnson & Buss (1967b) first concluded that spermatogenesis in the elephant is not altered after the onset of puberty. Additional studies determined that a well-defined breeding season does not exist in male African elephants (Buss & Smith, 1966;Laws, 1969;Hanks, 1972) and no seasonal variation is evident in the reproductive hormone concentrations (McNeilly et al, 1983).…”

Section: Discussionmentioning

confidence: 99%

“…Histological and biochemical features ofthe male reproductive tract have also been described using post-mortem tissue from elephants culled to avoid over-population (Johnson & Buss, 1967a;Short, Mann & Hay, 1967;Holt, Jones & Skinner, 1980;Jones, 1980;Jones & Brosnan, 1981). Less emphasis has been placed on establishing reproductive traits of live bull elephants because of inherent difficulties associated with handling, anaesthesia and animal availability.…”

Section: Introductionmentioning

confidence: 99%

Electroejaculation, semen characteristics and serum testosterone concentrations of free-ranging African elephants (Loxodonta africana)

Howard

Bush²,

Vos

et al. 1984

Reproduction

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Summary. A regimented electroejaculation protocol (120 electrical stimulations; 10\ x=r eq-\ 30 V) was used to collect semen and characterize ejaculate quality from 9 adult, free\x=req-\ ranging African elephants under anaesthesia. Eight of the 9 ejaculates contained high concentrations of progressively motile spermatozoa. The overall mean ejaculate volume, sperm concentration/ml ejaculate, sperm motility, sperm status and ejaculate pH were 93\m=.\3 ml, 2408\m=.\6\m=x\106 spermatozoa/ml, 70%, 3\m=.\9and 7\m=.\4, respectively. A high percentage (mean 77\m=.\5%) of spermatozoa within each ejaculate was morphologically normal. Of the aberrant spermatozoa, 72% had a cytoplasmic droplet defect. When sperm viability was tested in vitro at 37\x=deg\C,sperm motility rating declined by at least half of the initial assessment within 3\m=.\5h of semen collection. Generally, spermatozoa maintained motility in vitro for < 6 h. Serum testosterone ranged from 1\m=.\4to 8\m=.\2 ng/ml in 4 males evaluated in the morning (07 :30\p=n-\08:00 h). In 4 of the 5 bulls assessed in the afternoon (15 :00\p=n-\18 :00 h), testosterone levels were <0\m=.\9ng/ml. The remaining bull, evaluated at 16:00 h, had exceptionally high testosterone concentrations (peak 25\m=.\6 ng/ml) and a preputial discharge potentially indicative of 'musth'. The present study demonstrates that high quality semen can be collected consistently from the African elephant and that striking differences exist in serum testosterone amongst free-ranging males which may be due, in part, to a diurnal rhythm.

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Relationships of leydig cell characteristics and intratesticular testosterone levels to sexual activity in the African elephant

Buss

Johnson

1967

Anat. Rec.

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Histological characteristics of testis tissues from 25 African elephants (Loxodonta africana) collected in Uganda, showed no consistent relationships among the following variables : Leydig cell size, cytoplasmic characteristics, and abundance; testicular testosterone content; and age. From these findings, plus field observations of sexual behavior, emerges the hypothesis that individual cyclicity in Leydig cell function was inherent in the elephant population studied. Testosterone content of testes from 32 elephants (including the 25 studied histologically) suggested that lone bulls were not of a senile nature since they contained relatively large quantities of testosterone and were relatively young (from about 12 to 25 years of age). Also, lone bulls were observed searching out estrous females. Among bulls collected from family units and herds, testosterone levels and behavior differed conspicuously. Behavior appeared to be directly related to testosterone content in several instances. Nonaggressive behavior among members of bull herds, plus the high proportion of such individuals with low testosterone content, suggest that some of these animals were in a depressed phase of sexual activity whereas others were undergoing pubertal development.

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The Testis of the African Elephant (Loxodonta Africana)

Cited by 11 publications

References 4 publications

The development of the reproductive organs of the male giraffe, Giraffa camelopardalis

The development of the reproductive organs of the male giraffe, Giraffa camelopardalis

Electroejaculation, semen characteristics and serum testosterone concentrations of free-ranging African elephants (Loxodonta africana)

Relationships of leydig cell characteristics and intratesticular testosterone levels to sexual activity in the African elephant

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