Geckos (Suborder Gekkota: the geckos and pygopodids) are an extremely diverse and species rich group. Geckos comprise about 14% of all reptile species with over 1400 described species in 118 genera. Geckos are widely distributed in both the eastern and western hemispheres and can be found on numerous oceanic islands.
Geckos are perhaps best known for their climbing abilities. Hair-like bristles on their feet, known as setae, allow geckos to climb on a variety of surfaces, including glass. Individual seta possess branching projections at the tip. The contact of the finely branched setae with a surface produces millions of weak molecular attractions allowing the gecko to stick. Gecko feet never lose their “stickiness”. In fact, dead geckos still retain the ability to stick!
Adhesive toepads have been gained and lost many times during the course of gecko evolution. Geckos have also developed a variety of adhesive toepad forms. Above are just a few examples. Clockwise (from upper left) Ptyodactylus guttatus, Phelsuma laticauda, Sphaerodactylus elegans, and Hemidactylus frenatus.
Hemidactylus garnotii toepad
Geckos are the only lizards to regularly vocalize. Many species use a series of short chirps in a variety of social interactions. Most geckos are nocturnal although there are some exceptions and diurnality seems to have evolved independently several times (e.g. Cnemaspis, Sphaerodactylus, Gonatodes, Lygodactylus, Narudasia, Phelsuma, Quedenfeldtia, and Rhoptropus).
Reproductive traits in geckos are extremely varied. Nearly all geckos are oviparous (egg-layers) with the exception of the New Zealand geckos (Naultinus, Dactylocnemis, Woodworthia, Tukutuku, Toropuku, Mokopirirakau, and Hoplodactylus) and Rhacodactylus trachyrhyncus (from New Caledonia) which are live-bearing. Oviparous geckos may lay hard-shelled eggs (e.g. Sphaerodactylidae, Phyllodactylidae and Gekkonidae) or soft-shelled eggs (e.g. Diplodactylidae, Carphodactylidae, Pygopodidae, and Eublepharidae). Most geckos reproduce sexually although there are some parthenogenetic forms such as Lepidodactylus lugubris, Heteronotia binoei, Nactus pelagicus, Hemiphyllodactylus typus, and several species of Hemidactylus which consist of all-female populations. Geckos posses both genetic sex determination (e.g. Coleonyx, some Gekko, pygopodids), with either male or female heterogametey, and temperature-dependant sex determination (e.g. Eublepharis macularius, Hemitheconyx caudicinctus and Phelsuma madagascariensis).
Click on the names below to see photos of representative species from each of the seven gecko families. Photos of over 160 gecko species in all!