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Hi there!Just wondering somewhat about the real difference between the eunectes murinus and e.m. gigas. Is it a true subspecie or just a casual size difference?

>>Hi there!Just wondering somewhat about the real difference between the eunectes murinus and e.m. gigas. Is it a true subspecie or just a casual size difference?

Hi,

A recent revision of the anacondas suggests that gigas is not a different subspecies (and there is no well-substantiated size difference) - there are no consistent differences.

Reference: Dirksen, L. (2002) Anakondas. Natur und Tier - Verlag, Münster.

Cheers,

Wolfgang
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Is there any difference in how they look? Pictures?

The morphological differences between E. m. murinus and E. m. gigas are almost non-existent, and apparently not enough to warrant their listing as valid subspecies of E. murinus by the most recent study. See Wulf's post above on the reference to Dirksen, 2002. Most others are in agreement as according to other study data in the literature, the ventral counts, dorsal scale rows, subcaudals, supralabials, and infralabials of each do not show enough variation to be significant. It has been reported however, that murinus, or the southern population, appears to reach a slightly larger adult size than the northern population, but this is not necessarily a subspecific characteristic and is more likely a geographical variation of the same species caused by slight differences in habitat. It was also based on only a small number of snakes in the study group. The only other difference in appearance that is visibly discernible is that the northern population does tend to show yellow or orange in the postocular stripe to a much greater degree than is seen in the amazon basin population, which tends to have a postocular stripe that closely matches the green ground color of the animal. I have seen a few live anacondas and many in photographs that seemed to have accurate locality data, and this postocular color theory appears to hold true in many cases, but not always. It has been reported that some southern populations have been found with reddish-orange postocular stripes, specifically in Peru. Again, this is more than likely a geographical characteristic of the same species and not indicative of different subspecies. Hope this helped answer some of your questions.

Kelly