gecko (gĕk´ō), small or medium-sized lizard of the family Gekkonidae. Some 1,500 species are distributed throughout the warm regions of the world, mostly in the Old World. Despite folklore to the contrary, their bite is not poisonous.
Many gecko species are arboreal, while others inhabit human dwellings. Most lack movable eyelids and have characteristic pads on the undersides of their feet that enable them to cling to smooth surfaces and to run upside down on ceilings. The pads contain microscopic backward-projecting hairs covered by tiny pads that may generate an adhesive force through van der Waals attractions (see intermolecular forces). Geckos are unique among lizards in that they possess voices, and different species make characteristic sounds. They feed on small animals, chiefly insects. Nearly all lay eggs.
The largest species is the 14-in. (35.5-cm) tokay, Gekko gecko, of SE Asia. The wall gecko, Tarentola mauritanica, of the Mediterranean region is commonly seen basking by day on walls and rocks; it hunts by night. There are two native species in the United States, the leaf-fingered gecko (Phyllodactylus tuberculatus) of extreme S California and Baja California, and the banded, or ground, gecko (Coleonyx variegatus) of the deserts of the SW United States and N Mexico. The latter is a ground-dwelling form and lacks foot pads. In Florida there are several introduced West Indian species as well as the widely distributed Turkish gecko, Hemidactylus turcicus, originally from Africa.
Geckos are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Gekkonidae.
GECKO , reptile of the order Lacertilia. Six genera belonging to the Gekkonidae family are to be found in Israel. The most common is the house gecko, Hemidactylus turcicus, a nocturnal lizard up to about 4¾ inches (12 cm.) in length, with a soft speckled hide and prehensile feet which enable it to climb walls. Two animals referred to in the Bible are likely to be identical with the gecko. The anakah is included among the unclean swarming things (Lev. 11:30) and has, according to the Mishnah (Ḥul. 9:2), a soft hide. The word anakah means "groan", and the gecko does in fact emit a sound reminiscent of the groan of a sick person. The Book of Proverbs, in its enumeration of the "things which are little upon the earth, but… are exceeding wise" (30:24), mentions the semamit, which "taketh hold with her hands, and is in kings' palaces" (ibid., 28). This description fits the ubiquitous gecko which climbs on walls with feet that resemble hands. Although many other identifications have been suggested for the anakah and the semamit, the gecko fits them best.
I. Aharoni, Torat ha-Ḥai, 1, pt. 3 (1930), 62–66; Tristram, Nat Hist, 265f.; J. Feliks, Animal World of the Bible (1962), 97. add bibliography: Feliks, Ha-Ẓome'aḥ, 207.
geck·o / ˈgekō/ • n. (pl. -os or -oes) a nocturnal and often highly vocal lizard (Gekkonidae and related families) that has adhesive pads on the feet to assist in climbing on smooth surfaces.