Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 20 May 2010

Reproductive Activity of the Andean Frog Ranitomeya virolinensis (Anura: Dendrobatidae)

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Page Range: 211 – 217
DOI: 10.1643/CE-09-161
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Abstract

We studied the pattern of annual reproductive activity in the Andean dendrobatid frog Ranitomeya virolinensis by comparing age–sex structure of the population, morphology, and morphometry of gonad among months and between seasons. The focal population is found in a mountain habitat with a bimodal pattern of rains, which suggests a seasonal pattern of reproduction, as has been observed in other Neotropical frogs. Mature and reproductive females and males were collected during the entire year and their reproduction is continuous. Sexual maturity was reached in both sexes near 16.0 mm snout–vent length (SVL); females are significantly larger than males. The diameter of the ovary and of the largest follicles did not show significant differences among months or between seasons. Clutch size in all mature females was only one egg per oviposition event; however, the simultaneous presence of advanced vitellogenic follicles with the oviductal egg suggests that females produce several clutches with short inter-clutch intervals. Testes of all mature males had seminiferous tubules with cysts of all spermatogenic stages and free spermatozoa in the lumen in each month we sampled. The size of testes did not differ among months or between seasons. Therefore, the ability to produce ova and spermatozoa is continuous throughout the year in this species. Because juveniles in the smallest size classes were observed in all months, we assume that reproduction is continuous. The continuous reproductive activity of R. virolinensis is likely favored by its semi-terrestrial mode of reproduction, in an environment where direct resources for reproduction, such as moist ground for oviposition and phytotelmata for rearing tadpoles, are available despite a seasonal rainfall pattern.

Copyright: 2010 by the American Society of Ichthyologists and Herpetologists
Fig. 1
Fig. 1

Population age–size categories composition. ○, Adult females; ▪, Adult males; , Juveniles. Shadow area behind represents the rainfall pattern. Arrows denote minimum size of sexual maturity in both males and females.


Fig. 2
Fig. 2

Population structure displaying reproductive status of adult females (A) and males (B).


Contributor Notes

Associate Editor: M. J. Lannoo.

Laboratorio de Biología Reproductiva de Vertebrados Escuela de Biología, Universidad Industrial de Santander, Bucaramanga, Colombia, E-mail: (MVV) mercedesvalderrama@gmail.com.
Grupo de Estudios en Biodiversidad, Escuela de Biología, Universidad Industrial de Santander, Bucaramanga, Colombia, E-mail: (VHS) vserrano@uis.edu.co, and (MPR) mpramir@gmail.com. Send reprint requests to MPR.
Received: 27 Aug 2009
Accepted: 10 Dec 2009
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