REPRODUCTIVE BIOLOGY OF PHYMATURUS SPECTABILIS (LIOLAEMIDAE): FEMALES SKIP REPRODUCTION IN COLD AND HARSH ENVIRONMENTS OF PATAGONIA, ARGENTINA

BORETTO, J.M.; CABEZAS-CARTES, F.; F. TAPPARI; MÉNDEZ DE LA CRUZ, F; SINERVO, B.; A. SCOLARO; IBARGÜENGOYTÍA, N.R.

Herpetological Conservation and Biology

Springs Preserve

Año: 2014 vol. 9 p. 170 - 180

1931-7603

Herein we describe the reproductive biology of Phymaturus spectabilis that inhabits rocky outcrops in cold and arid environments of the Patagonian steppe of Argentina. We studied the male and female reproductive cycles, mean annual reproductive output, allometric changes along ontogeny, and sexual dimorphism, using mainly a non-invasive methodology, which is here applied for the first time in Argentina. This non-invasive method was corroborated with data from euthanized individuals through observation, classification and measurement of the female reproductive tract and ovaries, and the histology of testicles and epididymis in males. The presence of males with spermatozoa in the epididymis from early spring and pregnant females from mid spring shows that mating, ovulation and egg development occurs at the beginning of the activity season. Births occur in midsummer and females give birth to two offspring. The presence of half of the adult females with a non-reproductive condition during the entire reproductive season, simultaneously with vitellogenic or pregnant females, demonstrates that not all of the adult females in this population reproduce every year. Females exhibited an annual to biennial cycle due to sometimes skipping a year of reproduction, and males exhibited an annual cycle. Phymaturus spectabilis support a common pattern of a low mean annual reproductive output in the genus Phymaturus. The low frequency of reproduction and the low mean annual reproductive output are risk factors in the life history of this species, together with its microendemic character, since their habitat is restricted to an area of 70 Km2 of fragmented and rocky plateaus, in the poorly-protected steppe of Patagonia Argentina.