Monday, August 18, 2008

Herp of the Day: Hemidactylus

The House Gecko genus, Hemidactylus, is perhaps the most successful of all geckos. Representatives have introduced themselves all over the world in just about any city in warm climates. They are particularly abundant in areas such as ports where they come in on shipping and establish themselves. They don't make it up to here in New York (too cold in the winter), but I've run into them in all of my more tropical travels, including restaurants in Mexico and bars in Costa Rica, and they are abundant in cities in the southern half of the US. These resilient nocturnal geckos love to run around on ceilings, catching insects drawn to the lights. In some buildings they can become downright dense. My friend Eric counted 74 H. frenatus in one motel in Papua New Guinea.

The House Gecko in its native habitat (Source)

There are around 80 species of Hemidactylus, with only of few of these making up the majority of the species that have been traveling the world. The widely traveled species (coincidently also the most common Hemidactylus available in the pet trade) include H. brookii (Brook's House Gecko), H. frenatus (House Gecko), H. garnotii (Indo-Pacific Gecko), H. mabouia (Tropical House Gecko), H. platyurus (formerly Cosymbotus platyurus, Flat-tailed House Gecko) and H. turcicus (Mediterranean House Gecko). All of these are small, brown or grayish, pebbly gecko species that are very difficult to tell apart - the Little Brown Job's of geckos. Some of these species, such as garnotii, are parthenogenetic (female-only, reproducing asexually) which facilitates their world-wide introductions.

So sweet and innocent, as they conquer the world

I haven't actually keyed out any of the Hemidactylus I've seen on my tropical ventures, but a while back my friend Amy acquired a few House Geckos from the local pet store, providing me with an exercise in identification. It turns out that the two individuals she acquired from the tank of house geckos at the store were two different species! I of course wanted to go back and identify everything else in the tank to see just how many Hemidactylus were in that grab-bag, but alas I never did.

Here they are, A and B. Any guesses?

Hemidactylus A

Hemidactylus B

You have no idea, right? Well that's why I'm here. Here are the feet if that helps:

It didn't? Oh well. Hemidactylus A is the easy one, although that may not be apparent from the photo above. This species resembles Flying Geckos (Ptychozoon) in having flaps of skin down the sides of the body and a dorso-ventrally flattened tail:

This is Hemidactylus [Cosymbotus] platyurus, the Flat-tailed House Gecko. The first time I encountered this species in a local pet store, I thought they were in fact young Ptychozoon (this was in the early days of my interest in geckos, forgive me here), so I asked the clerk if they were Flying Geckos or the House Geckos as labeled. The clerk replied that they were baby Bearded Dragons. Go figure. Anyways, here are a few more pictures of platyurus:

Hemidactylus B is the Indo-Pacific House Gecko, Hemidactylus garnotii, a parthenogenetic species. Enjoy a few photos of this species, recognizable by the yellowish underside, the rings of tubercles around the tail, and the pattern of light spots on a darker background.

Not all species of Hemidactylus are this plain, just the species that make it all over the world. For some interesting species, try giganteus, maculatus, triedrus, and others.


  1. I had them in a hotel in Costa Rica. Some were REALLY tiny babies and others were several inches long. I loved having them around.

  2. I just found your post while trying to identify the gecko that was trapped in my sink this evening. I'm in the Spring, Texas area and they are EVERYWHERE, though I grew up in the city of Houston and we rarely saw them there! I'd be interested in identifying what species is here. Please check out my blog, I can try to get some photos for you (I'm a photographer) if you're interested in trying to figure out what they are. Thanks for the info (though I would prefer they were not IN my house).

  3. Can these gecko(s) take out my cockroach infestation in my apartment (four-plex), and then I still be able to catch all the geckos and sell/gift/otherwise get rid of them when the cockroaches are gone? I live in Utah. And do geckos bite? are they safe for infants and toddlers?

  4. Keshia - No, No, Yes, and no, not safe for the geckos