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Vol. 51 No. 5, 2012
Reproductive Patterns of Captive Male and Female Monocled
Cobra, Naja kaouthia (Lesson, 1831)
Panas
Tumkiratiwong1, Worawitoo Meesuk1, Lawan Chanhome2,
and Anchalee Aowphol3,*
1Physiology
Division, Department of Zoology, Faculty of Science, Kasetsart
University, Bangkok 10900, Thailand
2Snake Farm, Queen Saovabha Memorial Institute, Thai
Red Cross Society, Bangkok 10330, Thailand
3Department of Zoology, Faculty of Science, Kasetsart
University, Bangkok 10900, Thailand
Panas Tumkiratiwong, Worawitoo Meesuk, Lawan Chanhome,
and Anchalee Aowphol (2012) We monitored the morphology and histology
of male and female reproductive systems and plasma levels of male
testosterone and female estradiol to describe the reproductive pattern
of captive monocled cobras (Naja
kaouthia). Gonads
were collected in May and Nov. 2007, and monthly blood samples were
collected from Jan. to Dec. 2007, from captive snakes at the Queen
Saovabha Memorial Institute, Bangkok, Thailand. Male testes were
hypertrophic in May corresponding to spermatogenetic events and had
regressed in Nov. in the absence of spermatogenetic events. We
found that spermatozoa were stored in the epididymides in both May and
Nov. Male testosterone levels peaked in Oct. preceding the Nov.
mating time. In May, the granulosa layer of previtellogenic
follicles contained 3 distinct cell types of small, intermediate, and
large pyriform cells. Intermediate and large pyriform cells had
disappeared from the granulosa layer of the vitellogenic follicles in
Nov. Three follicular types of atretic, previtellogenic, and
vitellogenic follicles were common inside the ovaries in Nov. The
corpora lutea had regressed to a corpora atretica in Nov. The
plasma level of female estradiol surged in Nov. coincident with the
mating time and vitellogenic events. We suggest that the
reproductive pattern of captive monocled cobras exhibits either
postnuptial spermatogenesis or a dissociated reproductive pattern.
Key words: Elapidae, Estradiol, Testosterone,
Pyriform cells, Spermatogenesis.
*Correspondence: Tel: 662-5625555 ext. 3273. Fax:
662-5625555 ext. 3202. E-mail:fsciacl@ku.ac.th
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