Reproductive and fat body cycles of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata, Tropiduridae) in a caatinga area of northeastern Brazil

Abstract

This study assessed the reproductive and fat body cycles of Tropidurus hispidus (Spix, 1825) and T. semitaeniatus (Spix, 1825) in an area of caatinga in the Seridó of Rio Grande do Norte, Brazil, from October 2006 to May 2008. In both species, the females were reproductively active from the middle of the dry season to the beginning of the rainy season. Female reproductive activity was infl uenced by precipitation, whereas males exhibited spermatozoa in their testes throughout the year, and their reproductive activity was not related to any of the climatic variables analyzed. Mean clutch size (± SD) was 8.1 ± 2.0 and 2.1 ± 0.6 eggs in T. hispidus and T. semitaeniatus, respectively, and was signifi cantly related to female body size only in T. hispidus. The fat stock varied inversely with reproductive activity in the two species, and there was no difference in fat body mass between females and males. The effects of precipitation on the length of the breeding season of these two Tropidurus species suggest that their reproductive cycles are related to the microclimatic conditions suitable for embryo development, as well as for the neonates' emergence and survival especially during the rainy season, which may offer greater food availability to the hatchlings.Key words: body size-fecundity, clutch size, minimum size at maturity, reproduction, semiarid. RESUMENEste estudio evaluó los ciclos reproductivos y de grasa corporal de Tropidurus hispidus (Spix, 1825) y T. semitaeniatus (Spix, 1825) en una área de caatinga en el Seridó de Rio Grande do Norte, Brasil, de octubre de 2006 a mayo de 2008. En ambas especies, las hembras se encontraron reproductivamente activas a partir de mediados de la estación seca para el inicio de la temporada de lluvias. La actividad reproductiva de las hembras fue infl uenciada por las precipitaciones, mientras que los machos presentaron espermatozoides en los testículos durante todo el año, y su actividad reproductiva no fue relacionada con ninguna de las variables climáticas analizadas. El tamaño medio (± DE) de la nidada fue de 8.1 ± 2.0 y 2.1 ± 0.6 huevos en T. hispidus y T. semitaeniatus, respectivamente, y se relacionó signifi cativamente con el tamaño corporal de la hembra solo en T. hispidus. La reserva de grasa varió inversamente con la actividad reproductiva en las dos especies, y no hubo diferencia en la cantidad de grasa corporal entre hembras y machos. Los efectos de la precipitación sobre la duración de la temporada reproductiva de estas dos especies de Tropidurus sugieren que sus ciclos reproductivos están relacionados con las condiciones microclimáticas adecuadas para el desarrollo del embrión, así como para la emergencia de los recién nacidos y su supervivencia, especialmente durante la temporada de lluvias, que es la que puede ofrecer una mayor disponibilidad de alimentos para las crías.Palabras clave: relación tamaño corporal y fecundidad, reproducción, tamaño de la postura, tamaño mínimo de madurez, semiárido.

Ovarian follicular cycle of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata: Tropiduridae) in a semiarid region of Brazil

“…Clutch size was estimated consistent with a previous study (see RIBEIRO et al 2012) by counting the number of vitellogenic follicles or eggs in the oviducts. In the case of females with simultaneous occurrence of vitellogenic follicles and eggs in the oviducts or corpora lutea, clutch size was estimated only by the number of oviductal eggs.…”

“…The role of atresia can include limiting the number of eggs during a particular reproductive cycle through digestion and/or removal of ooplasma content (HERNANDEZ-FRANYUTTI et al 2005). At ESEC Seridó, the average clutch size of T. hispidus was 8.1 ± 2.0 eggs, whereas that of T. semitaeniatus was 2.1 ± 0.6 eggs (RIBEIRO et al 2012). Tropidurus semitaeniatus individuals are dorsoventrally flattened and are morphologically and behaviorally adapted to utilize rock crevices to es- cape predation.…”

“…To better understand the influence of seasonality on the reproductive activity of lizards, ovarian histological studies seek to characterize the phases of folliculogenesis in different seasons (GOLDBERG 1970, MANES et al 2007. In a previous study we conducted seasonal analyses of the reproductive activity and fat body mass in females and males of T. hispidus and T. semitaeniatus (RIBEIRO et al 2012). Histological and cytological descriptions of the reproductive activity of Brazilian lizards, particularly those inhabiting the Caatinga, are scarce.…”

Feeding and reproduction ecology of the lizard Tropidurus torquatus (Squamata: Tropiduridae) in a rock outcrop area in southeastern Brazil

“…There was no infl uence of seasonality on the fat body size in females. Vitt & Goldberg (1983) and Ribeiro et al (2012) obser ved for T. hispidus in Brazilian caatinga biome that fat body mass decreased as the reproductive period advanced. Our data for T. torquatus do not demonstrate this same process.…”

Supplemental Material for 'A new collared lizard (Tropidurus, Tropiduridae) endemic to the western Bolivian Andes and its implications for seasonally dry tropical forests. (American Museum novitates, no. 3896)'

“…Adult male specimens were identified based on the presence of colored patches of scales varying from yellow to black on the ventral side of thighs and precloacal flap. Males also have wider heads and thinner bodies than females of the same body size (Pinto et al, 2005;Ribeiro et al, 2012). Sex determination of juveniles is not as obvious, and required the examination of gonadal condition.…”