Quadricornis- why some have only 2 horns...

[Jerm]

Does anyone know why alot of the quads that I see in pictures have 2 horns? Does it depend on which region that they are from and will their offspring have both 2 and 4 horns? I have aquired a male with 2 horns and a male with 4 horns but everything else is pretty much identical about them. I've heard of them having more than 4 but i haven't heard anyone discuss less than 4. Is it then called a Duocornis? Haha! Kidding. Thanks for the info.

 

[Chris Anderson]

Ch. quadricornis systematics is kind of a mess. Ch. quadricornis gracilior males are said to be able to have up to six horns but can also have fewer while Ch. quadricornis quadricornis males are said to only be able to have up to four but again, can have fewer. Two horned males are rather common and I can only assume that both subspecies are capable of having individuals with this number. Unfortunately, research in that part of the world on chameleons is extremely limited. Ch. q. quadricornis is said to only come from Cameroon while Ch. q. gracilior is said to come from Cameroon and Nigeria. Unfortunately, most of the Ch. quadricornis that are imported are actually coming from Equatorial Guinea which neither subspecies, according to my data, is reported from in the scientific literature. Since locality data is not of any use to try to identify the subspecies, we have to rely on morphological information to identify the subspecies. Unfortunately, the only reliable morphological character I know of to differentiate is the third pair of horns in the males (which not all have and of course, which females lack entirely). As a result, pretty much all the Ch. quadricornis identification you see past the species level is a guess unless its a male with 6 horns (and I venture to guess this might not be an accurate differentiation either to be honest). The red nails/clear nails, orange head and all those other varying characters really are not reliable methods of determining subspecies, IMO.

Chris

 

[Chris Anderson]

I just pulled out the description of Ch. q. gracilior and I have a few other thoughts on identification. Keep in mind the description is in German so I can't read it so this is based on comparison of photos of a single specimen of each subspecies and a specimen sketch of each subspecies and there will be variation and probably overlap. It seems that Ch. q. gracilior has a smaller sailfin at the base of the tail and a less well pronounced dorsal sail along the dorsal crest (the laterally compressed "fin" along the dorsal crest area like Ch. cristatus is known for). Further, it seems that the angle of the casque in Ch. q. quadricornis is more extreme then in Ch. q. gracilior. As for females or the variation in males, who knows, this is definitely not an easy species to differentiate its subspecies.

Chris

 

[Jerm]

That's very interesting, thanks Chris. The information available on these guys is very limited. It sounds like identifying their locale is a shot in the dark without knowing where they were captured originally. If a female comes in on the same shipment then all you can do is assume that you have a pair of the same sub-species. Sounds like we need to do more research on wild caught populations. If i only had a Biology degree... I will post some pictures of the new guys soon.