Hoplodactylus

Hoplodactylus
Hoplodactylus duvaucelii
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Lacertilia
Family: Gekkonidae
Subfamily: Diplodactylinae
Genus: Hoplodactylus
Fitzinger, 1843
Species

H. duvaucelii, H. delcourti.

Hoplodactylus is a genus of gecko endemic to New Zealand, one of the seven genera of geckos found only in New Zealand. Hoplodactylus comprises two species of large to gigantic brownish lizards, one extinct and one surviving only on predator-free islands.

Description

Species in this genus tend to have rather dull colouration with little variation on a generally brown/grey theme, although mottled greens are seen in some species, notably the forest gecko (Hoplodactylus granulatus). The one exception to this rule of general drabness in colouration is the striking "herring boned" colour pattern of green, brown, black and white that is displayed by the "Harlequin Gecko" (Hoplodactylus rakiurae).

Although generally species of this genus cannot compete with those of Naultinus in terms of their vivid and beautiful colouration, Hoplodactylus species do have the ability to subtly change their skin colour pattern to give better camouflage, thus reducing the risk of predation. "In some of the Hoplodactylus species, the ability to change colour provides a supplementary method of thermoregulation"(*1). When basking in cold conditions they can darken their skin to increase the amount of heat absorbed and conversely they can lighten the shades in hot weather to reflect more light and keep cool. All species in this genus have more or less nocturnal activity patterns in contrast to the solely diurnal nature of Naultinus species and unlike species in the latter genus, are not purely arboreal and will forage on the ground.

Hoplodactylus species do not have prehensile tails and are thus generally less reluctant to drop them when disturbed by predators than species in the Naultinus genus - however, there are two exceptions, the Goldstripe gecko Hoplodactylus chrysosireticus and the Pacific gecko Hoplodactylus pacificus both have a very flighty disposition and will often shed their tails at the slightest provocation.

Many species of the Hoplodactylus genus also have toes that are broader and more expanded than their relatives in the Naultinus genus.

The key differences between New Zealand's two endemic gecko genera are summarised in the table below

Hoplodactylus Naultinus
Mainly grey-brown Mainly green
Nocturnal Diurnal
Arboreal: on foliage Terrestrial - sometimes on tree trunks
Active-prey-searching Sit-and-wait predator
Fast moving Slow moving
Can change intensity of skin colour Skin colour intensity cannot be changed
Wide, non-prehensile tails - readily shed Narrow, tapering prehensile tails - reluctantly shed
Wide toe pad to assist climbing smooth surfaces Thin toe pads adapted for grapsing twigs and foliage

*references used for this table;[1][2]

Species

Hoplodactylus duvaucelii is the largest species of gecko remaining in New Zealand although due to predation by introduced mammals such as the Norway rat their range is at present restricted to pest-free offshore islands.

The extinct Kawekaweau/Delcourt's gecko Hoplodactylus delcourti was the largest known gecko in the world. It was first described in 1986 though the only known specimen was collected in the early 19th century but was overlooked in a French museum for more than a century.

Species list

References

  1. George Gibbs, "Ghosts of Gondwana; the History of Life in New Zealand", Craig Potton publishing, 2006
  2. Brian Gill and Tony Whitaker, "New Zealand Frogs and Reptiles", David Bateman publishing, 1996
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