Ecology of the growth of Anolis nebulosus (Squamata: Dactyloidae) in a seasonal tropical environment in the Chamela region, Jalisco, Mexico

Abstract

Juvenile growth rates are thought to be restricted by available food resources. In animals that grow throughout the year, such as tropical lizards, growth is therefore predicted to be faster during the rainy season. We test this prediction using a population of Anolis nebulosus by describing the growth trajectories of both sexes using nonlinear regression models, and we then correlate the growth rates of individuals with food available in the environment, precipitation, and temperature. The Von Bertalanffy model fits the growth rates of the females better, while the logistic‐by‐length model fits the males better. According to both models, the males grew faster than females, reaching slightly smaller sizes at adulthood. Males reached sexual maturity when 35 mm long, at an age of seven months, and females matured at 37 mm (SVL), taking nine months to reach this size. In 1989, juvenile males and females grew more in both seasons (rainy and dry) than adults; for 1990, there were no differences by season or between age classes. These results are interesting since in the 1989 and 1990 rainy seasons, practically the same orders of prey and the greatest abundance of prey available in the environment were registered. A possible explanation could be that predation was more intense in 1990 than in 1989. There is little evidence that food, temperature, and humidity affect growth rates of A. nebulosus , refuting our predictions. This is mainly due to the low variation in growth observed in 1990. Therefore we think that the growth of this species reflects a complex combination of ecological and genetic factors.

Determinate growth is predominant and likely ancestral in squamate reptiles

“…First, numerous capturerecapture field studies (e.g. [25,[36][37][38][39]), as well as laboratory experiments (e.g. [40,41]), involving distantly related species of reptiles suggest that growth is minimal or non-existent in older individuals.…”

Morphological evidence of sexual dimorphism in a Continental anole species of southeastern of Mexico

“…However, it would be difficult to test this hypothesis, since few studies have demonstrated this relationship reliably (Berns 2013). For example, Márquez et al (2005), Siliceo-Cantero et al 2016and Hernández-Salinas et al (2019), observed that differences in growth rates and head size between the sexes in A. aquaticus and A. nebulosos allow them to feed on different types of prey during their development. Butler et al (2000) noted that the sexual dimorphism recorded in Anolis species of the Greater Antilles was correlated with the type of microhabitat and perch height that males and females use.…”

“…SD in the genus Anolis has been explained with reference to gular dewlap and other morphologic traits associated with body shape (ecomorphs) in West Island Anolis lizards (Butler et al 2007;Losos 2009;Johnson and Wade 2010), while SD in mainland Anolis species has mostly been related to SVL, perch use, and diet (Perry 1996;Ramírez-Bautista and Vitt 1997;Ramírez-Bautista and Benabib 2001). Despite this, there is little information about SD in most of the mainland Anolis species; therefore, it is necessary to determine whether SD occurs in other morphological structures beyond previously reported (Márquez et al 2005;Siliceo-Cantero et al 2016;Hernández-Salinas et al 2019). Therefore, the goal of this study is to analyze the SD of a tiny mainland anole species Anolis unilobatus Köhler and Vesely 2010; east pacific and central depression Chiapas clade see Gray et al 2019 (We will refer as Anolis unilobatus to the populations of the east pacific lineage, but we are aware of these populations belong to an evolutionarily independent lineage to the populations of the west pacific and of central America Gray et al 2019).…”

“…For this, we analyzed sexual differences in eight morphological characteristics through multivariate statistics. Anolis unilobatus is a slender, small body-sized, fast growth rate, with a short life expectancy such as many species of small-bodied-sized (Ramírez-Bautista and Vitt B I OD I V E R S I TA S 20 (11): 3347-3351, November 2019 3348 1997; Hernández-Salinas et al 2019). This species inhabits tropical forest, occupying tree branch and grass microhabitats (Lee 1980), as well as tree trunks, which has been referred to as a trunk ecomorph (Lee 1980).…”

Reproduction and sexual dimorphism in the viviparous lizard Sceloporus palaciosi (Squamata: Phrynosomatidae) from the Trans‐Mexican Volcanic Belt, Mexico

“…Larger males are better able to defend territories during reproduction because they have higher success rates in malemale combat. In addition, growth rate is faster in males than in females, as explained by the fact that they must prepare (during reproductive period) the site of courtship, mating and fertilization of eggs (Hernández-Salinas, Ramírez-Bautista, Cruz-Elizalde, Meiri, & Berriozabal-Islas, 2019;Ramírez-Bautista & Vitt, 1997). Female-biased SSD provides larger body sizes, which in females can increase fecundity by increasing space for developing embryos, allowing either for larger litter sizes or for larger body sizes at birth (Olsson et al, 2002;Pincheira-Donoso & Hunt, 2015;Scharf & Meiri, 2013).…”