Lizard predation by spiders: A review from the Neotropical and Andean regions

Abstract

Vertebrate predation by invertebrates has been classically underexplored and thus underestimated, despite the fact that many arthropods consume vertebrates. To shed some light on the relevance that spider predation may have upon lizards in the Neotropical and Andean regions, we compiled the available information in the literature on this trophic interaction. We found 50 reports of spiders consuming lizards in these regions, and the 88% of these were from the Neotropical region. Spiders belong to eight families, but Ctenidae and Theraphosidae were the most frequently reported predators. Lizards belong to 12 families, and the most commonly consumed species corresponded to the families Dactyloidae (all Anolis lizards), Gymnophthalmidae, and Sphaerodactylidae. Data suggest trophic spider-lizard associations between Ctenidae and Dactyloidae, followed by Theraphosidae and Liolaemidae. The body sizes of the spiders and lizards showed a positive relationship, and spiders were smaller than their prey. We conclude that various spider taxa can be considered lizard predators and they may be ecologically important in the Neotropical and Andean regions. However, spiders of prime predation relevance seem to be those of the Ctenidae and Theraphosidae families.

Keywords: Anolis; Central Chile; Ctenidae; Liolaemus; Theraphosidae; predator–prey interactions.

FIGURE 1

Geographical distribution of predation reports by spiders upon lizards (circles) in the Neotropical and Andean regions, showing the corresponding subregions (sensu Morrone, 2014, 2015). The spider families are indicated by circles of different colors, and numbers correspond to the references listed in Table 1. Asterisks correspond to the three new records reported in this study. Six reported records are not shown because their georeferenced location is missing (references 6, 9, and 10, cited by 11, 18, and 29, respectively; Table 1)

FIGURE 2

Percent of families of (a) spider predators and (b) lizard prey involved in the predator reports from the Neotropical and Andean regions

FIGURE 3

Heat map of predator–prey relationships between families of spiders (bottom) and lizards (right side). The small box shows the key color according to the observed number of predation reports

FIGURE 4

Correlation between body sizes of predators and prey (N = 28); carapace for spiders and snout–vent length for lizards. Data correspond to values reported in the literature (Table S1, see text) and not to the particular specimens reported in the studies listed in Table 1

FIGURE 5

New cases of spider predation on Liolaemus lizards in Central Chile. (a) Grammostola rosea consuming an adult of L. lemniscatus at Cerro Mariposa. (b) Predation upon a juvenile of L. nitidus by a mygalomorph spider Euathlus sp.: bi) The spider holds the lizard with its chelicerae and pedipalps; bii) ventral view of the semidigested lizard body. The head, neck, and one frontal leg of the lizard were already consumed. In addition, the cloacal region and the tail show lacerations (red arrows). The observation occurred at Altos de Cantillana. (c) Partially digested individual of L. tenuis found close to a burrow of G. rosea, at Lo Barnechea: ci) Lizard corpse close to the spider burrow; cii) ventral view of the lizard. Photos: (a) Andrés Guajardo‐Santibáñez, (b) Bernardo Segura, and (c) Nicolás Zañartu