Autecology of Kentropyx calcarata (Squamata: Teiidae) in a Remnant of Atlantic Forest in Eastern South America
Kentropyx calcarata is a widely foraging teiid lizard species that inhabits forest environments east of the Andes in South America. We studied the ecology of a K. calcarata population in a remnant of Atlantic Forest in Brazil and evaluated lizards' body temperatures, stomach content, activity time, body measurements, and reproduction stage. We tested whether: 1) body temperature was influenced by substrate or air temperatures, 2) diet composition varied according to age and sex, and 3) there was sexual dimorphism in body size and bauplan (morphology). Lizards were more active during the hottest hours of the day, commonly in the litter or fallen logs. Body temperatures were influenced more by substrate temperatures than by air temperatures. Diet was composed mainly of arthropods, with Orthoptera and Araneae as the most important categories (numerically and volumetrically). Diet composition was similar between sexes, but varied ontogenetically as an effect of body size, with juveniles eating smaller prey than adults. Females were larger than males and there was difference in bauplan between sexes. We found reproductive males and females throughout the year. Kentropyx calcarata is ecologically similar to other species within the genus and the family, suggesting great importance of the evolutionary history for the ecology of this species.
Kentropyx calcarata es una lagarto teíido ampliamente forrajero que habita en ambientes forestales al este de los Andes en América del Sur. Estudiamos la ecología de una población de K. calcarata en un remanente de Mata Atlántica en Brasil y evaluamos la temperatura, el contenido del estómago, la actividad, las medidas corporales, y la etapa de reproducción de los lagartos. Testamos si: i) la temperatura corporal fue influenciada por la temperatura del sustrato o del aire, ii) la composición de la dieta varió según la edad y el sexo, y iii) hubo dimorfismo sexual en el tamaño y bauplan. Los lagartos fueron más activos durante las horas más calurosas del día, comúnmente en la hojarasca o troncos caídos. Las temperaturas corporales fueron más influenciadas por las temperaturas del sustrato que las temperaturas del aire. La dieta fue compuesta principalmente por artrópodos, siendo Orthoptera y Araneae las categorías más importantes (numéricamente y volumétricamente). La composición de la dieta fue similar entre los sexos, pero varió ontogenéticamente, con los juveniles consumiendo presas menores que los adultos, como un efecto del tamaño. Las hembras fueron más grandes que los machos y hubo dimorfismo sexual en bauplan. Machos y hembras reproductores fueron encontrados durante todo el año. Hembras reproductoras también fueron encontradas en todos los meses del año. Kentropyx calcarata es ecológicamente similar a otras especies dentro del género y la familia, lo que sugiere una gran importancia de la historia evolutiva en la ecología de esta especie.Abstract
Resumen
Location of the private Conservation Unit “Reserva Particular do Patrimônio Natural” Gargaú, in the state of Paraíba, Brazil, municipality of Santa Rita.
Light microscopy showing seminiferous tubule of Kentropyx calcarata. Hematoxylin and eosin. (A) Seminiferous tubule of immature lizard. (B) Stage I of the spermatogenic activity cycle. (C) Stage II of the spermatogenic activity cycle. (D) Stage III of the spermatogenic activity cycle, showing spermatids at luminal margin. (E) Stage IV of the spermatogenic activity cycle. Note the presence of the Sertoli cells and the interstitial cells (Leydig cells). Tunica albuginea covered the testes (arrowheads). (F) Seminiferous tubule in stage V showing spermatogonia and spermatocytes in the germinative epithelium and lumen obstructed by cellular debris (*). Spermatogonia (sg), spermatocytes (sp), spermatids (sd), spermatozoa (sz), interstitial cells (i), Sertoli cells (SC), germinative epithelium (GE), and lumen (L). Scale bar = 50 μm.
Percentage of male Kentropyx calcarata according to stages of spermatogenetic activity throughout the months of the year. Letters on horizontal axis represent months of the year and sample sizes are indicated in parentheses.
Monthly distribution of the largest follicle and egg lengths in females of Kentropyx calcarata in an Atlantic Forest fragment. Letters on horizontal axis represent months of the year and sample sizes are indicated in parentheses. *, follicles and eggs registered in the same female in a given month.
Monthly distribution of male and female individuals of Kentropyx calcarata from Atlantic Forest according to snout–vent length (SVL). Letters on horizontal axis represent months of the year and sample sizes are indicated in parentheses. Horizontal lines represent minimum SVL at maturity.
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