Corallus caninus Nederland - website dedicated to the Emerald Tree Boa of South America

Localities or subspecies?
'More than 1 species appears to be masquerading under the taxonomic umbrella of C. caninus. Many hypotheses (e.g., refugia, riverine barrier, marine incursion) have been addressed in order to explain speciation in Amazonia, and various authorities have noted that any Amazonian speciation model will be complex and, to some extent, species-specific.
Collecting pieces of the “emerald puzzle” and their assembly is ongoing, with the analysis of morphological data hopefully providing additional insights into geographic variation and possible new taxonomic partitioning of C. caninus.' [Henderson].

It is with these words that I begin short synopsis of the several variations of Corallus caninus I have seen in collections during the 25 years I have been a herpetoculturist. Like in a few other species, e.g. Morelia viridis [green tree python] collectors began to attribute variations in colours and patterns to so-called 'localities'. Quite often, some of these localities were no more than the names of the 'ports of exit' in the original country or region where the animals were collected and shipped into the pet trade. In the Green Tree Python, many of these name still exist, e.g.: Merauke, Jayapura, Sorong, Bokondini, Manokwari etc. etc. Animals captured by trappers were taken to a central collection point, from where they were then exported to other countries.

This makes the concept of 'localities' as 'true geographical localities' very hard to prove. For example, a locality like Sorong [from where most GTPs were shipped when they began to become popular in the pet trade] is in the same geographical region as Manokwari [also a so-called locality], but both localities look very much the same. This also applies to other 'mainland localities' of this particular species of python. However, this cannot be said of the 'insular localities' of the green tree python. These are often strikingly different to the mainland localities, perhaps due to their geographical isolation from mainland variations.

Following the re-classification of the Corallus hortulanus complex by Henderson et al, we are now seeing the same phenomenon in Corallus caninus, but one with a marked difference, namely one in which the claims with regard to speciation or re-classification are being substantiated by extensive DNA analysis and meticulous scale-counting by dedicated taxonomists and biologists.
It is very surprising, as Henderson states, that little attention has been paid during the past 150 years to the biological relationships of C. caninus, in spite of the remarkable ontogenetic colour changes in juveniles, the very splendid adult coloration and its growing popularity among herpetoculturists. The various localities seem to suggest, as stated by Henderson, that we are in fact looking at several subspecies here. This topic has been brought to light particularly as a result of the growing popularity for the 'Basin' variant of Corallus caninus, which is found only in the Amazon river basin of S. America and nowhere else. Further studies on exact speciation are still ongoing [Hoogmoed et al] after the untimely death of Henderson who did much of the pioneering work in this field [see: The Emerald Puzzle: Geographic Variation in Corallus caninus - R. Henderson, IGUANA, March 2005.] So, let's take a closer look at what the discussion is all about....

First of all, the boa we now know as Corallus caninus was first described by LINNAEUS nearly 250 years ago. Other 'emerald' boas were also described from the same region (e.g., Boa aurantiaca by Laurenti in 1768 and Chrysensis batesii by Gray in1860). All of these 'emeralds' were finally classified as Corallus caninus by BOULENGER, in 1893.