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Oligospermia and azoospermia in non‐reproductive male Damaraland mole‐rats Cryptomys damarensis (Rodentia: Bathyergidae)
Author(s) -
Maswanganye K. A.,
Bennett N. C.,
Brinders J.,
Cooney R.
Publication year - 1999
Publication title -
journal of zoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0952-8369
DOI - 10.1111/j.1469-7998.1999.tb01039.x
Subject(s) - biology , sperm , reproductive biology , testosterone (patch) , reproduction , reproductive system , zoology , andrology , medicine , endocrinology , ecology , embryo , embryogenesis , botany , microbiology and biotechnology
The relationship between reproductive status and reproductive physiology was investigated in male Damaraland mole‐rats Cryptomys damarensis , an eusocial rodent that exhibits a marked reproductive division of labour. Testicular anatomical and histological morphometrics, selected sperm motion parameters and measurements of circulating plasma testosterone were studied in 44 males (17 reproductive and 27 non‐reproductive). Reproductive males were significantly larger than non‐reproductive males. Testicular mass of reproductive males, corrected for body mass, was significantly larger than in non‐reproductives. However, corrected testicular volume did not vary significantly between the two groups. Circulating plasma testosterone concentrations of reproductives and non‐reproductives were not significantly different (reproductive males 201.5 ± 56.5 pg/l vs 187.5 + 91 pg/l for non‐reproductive males). The quality of sperm was measured by the percentage of spermatozoa produced and the amount of immature sperm, and differed between the two groups. Reproductive males produced a greater proportion of motile sperm (77.8%) than non‐reproductives (56.3%). Non‐reproductive males were characterized by a greater proportion of immature sperm in the epididymis (79%) than the reproductives (25%). Interestingly, the spermatozoa of reproductive males were characterized by a greater percentage of head and tail defects. Oligospermia may be the result of a reduction in circulating follicle stimulating hormone, which acts upon the Sertoli cells of the seminiferous tubules, that in turn may be due to a lack of an opportunity to mate while in the confines of the colony in this obligate outbreeder.