Drinking behaviour inAnolis carolinensis(Voigt, 1837) andOplurus cuvieri(Gray, 1831) (Reptilia: Iguania: Iguanidae)

Abstract

The aim of this study is to describe the drinking mechanism in two iguanid species, Anolis carolinensis and Oplurus cuvieri. Both live in varied ecological environments where water may be either very abundant or exceedingly scarce. Anolis carolinensis is an arboreal species of the southern United States; in its environment, water is constantly available in drops or small reservoirs. Oplurus cuvieri lives in northwestern Madagascar, enduring very dry and very wet seasons and high insolation. In the dry season, few pools of water or dewdrops remain available. Light and X-ray filming of drinking revealed that the two species almost always use similar mechanisms to introduce water into the buccal cavity. During immersion, the tongue is used to collect water and push it from the front to the back of the buccal cavity. During emersion, water reaches the esophagus, mainly as a result of gravity. In A. carolinensis, this mechanism is used regardless of the amount of water available. In O. cuvieri, the role of the tongue is less important when water is abundant. In similar conditions, therefore, the two species of Iguania use similar mechanisms for collecting and swallowing water. This drinking mechanism has been observed in Lacerta viridis in the sister-group Scleroglossa.

Integumental water movement and rate of water ingestion during rain harvesting in the Texas horned lizard, Phrynosoma cornutum

“…Lizards have a diversity of oral glands with complex chemical roles (Kochva, 1978). The tongue plays diverse roles in feeding, drinking, chemoreception, and social interactions in lizards (Schwenk and Throckmorton, 1989;Bels et al, 1993;Wagemans et al, 1999;Schwenk, 1995Schwenk, , 2000. Tongue actions play a signi cant role in drinking by some lizards (Burrage, 1973;Fitzgerald, 1983;Bels et al, 1993;Vesely and Modry, 2002).…”

Natural drinking strategies

“…We note that, for dipping in nectar feeders, the high viscosity of nectar results in a thick layer of nectar on the tongue, and a relatively large volume of nectar transported to the mouth. For the lizard, the tongue speed for licking u ∼ 1 cm s −1 , so Ca = uµ/σ ∼ 10 −4 , while the tongue width w ∼ 4 mm and extrusion length l ∼ 2 mm are comparable to the capillary length l c (Wagemans et al 1999). Thus Landau-Levich-Derjaguin theory predicts that the film thickness of the water layer on the tongue is given by e ∼ l c Ca 2/3 ∼ 10 µm (Quéré 1999).…”

“…Assessment of the magnitudes of these dimensionless groups indicates the dominant forces at play. The (Morrison et al 1989), sheep (Bott, Denton & Weller 1965), cats (Reis et al 2010), monkeys (Maddison et al 1980), chickens (Heidweiller, van Loon & Zweers 1992), wild ducks (Kooloos & Zweers 1989), snakes (Berkhoudt, Kardong & Zweers 1995;Cundall 2000), rats (Weijnen 1998;McClung & Goldberg 2000), pigeons (Zweers 1982), finches (Heidweiller & Zweers 1990), phalaropes , turtles (Bentley, Bretz & Schmidt-Nielsen 1967;Davenport & Macedo 1990;Bels, Davenport & Renous 1995), lizards (Wagemans et al 1999), Texas horned lizards (Sherbrooke 2004), bats (Roces, Winter & von Helversen 1993;Winter & von Helversen 2003), sunbirds (Schlamowitz, Hainsworth & Wolf 1976), hummingbirds Tamm & Gass 1986), orchid bees (Borrell 2006(Borrell , 2007, bees (Harder 1986), mosquitoes (Rosenson, McCormick & Uretz 1996;Lee, Kim & Lee 2009), moths (Josens & Farina 2001), butterflies (Pivnick & McNeil 1985), ants (Paul & Roces 2003) and Rhodnius (Bennet-Clark 1963).…”

Mechanics and kinematics of fluid uptake and intraoral transport in the leopard gecko

“…It is, therefore, anticipated that the tongue’s morphology and functional anatomy, and those of associated areas of the buccopharyngeal region, will reflect efficient and effective transfer of water from the environment to the oral chamber and thence to the gut. Rarely, however, has the functional relationship between buccolingual morphology and drinking kinematics been explored (Kooloos & Zweers, ; Heidweiller et al , ; Kardong & Haverly, ; Thexton, Crompton & German, ; Wagemans et al , ; German, Crompton, & Thexton, ; Reis et al , ; Crompton & Musinsky, ; Gart et al , ; Houze & Damman, ; Rico‐Guevara et al , ).…”

“…Among iguanian lizards (currently assigned to the Toxicofera), the tongue is directly involved in prey capture (Schwenk & Throckmorton, ; Bels, ; Kraklau, ; Bels et al, ; Herrel et al , ; Meyers & Herrel, ; Schaerlaeken, Meyers & Herrel, ; Brau et al , ; Bels et al , ,b), but also plays an important role in drinking (Bels et al, ; Wagemans et al , ). The agamid Pogona exemplifies the differences in tongue protraction and deformation when employed in prey capture and drinking (Bels et al , ,b).…”