Not a formal but some more detailed S.gigantea complex explained.

Neil TW

Arachnopeon
Joined
Dec 22, 2012
Messages
24
Being one of the rarest, most high-priced species. Scolopendra gigantea from South America had always been in the hobby but due to the price and rarity factor seldom discussed on different forums had been done. Been lucky enough to have 2 of the "potentially different species" and some info and very clear photo kindly shared by a senior hobbyist on internet, now I can compare 3 of the "potentially different species" and post some reviews.

Since this discuss focused on "S.gigantea", I won't be discussing nor reviewing viridicornis complex and galapagoensis complex(those 2 complex are also really really messy complex).

And currently I'm aware of 4 significantly different appearance species from South America, one from Colombia to Isle Aruba, one live in Venezuela coastal region to Trinidad, one live in inland Venezuela region(which unfortunately I do not get any specimen to compare), and one from Northern Peru.

Since the coloration isn't a valid ID key I'll briefly talk about it only with it's "nickname".
Colombia-Isle Aruba:Brown color body with significantly lighter rear edge, red antenna, yellow leg with no rings, terminal tergite have small keel, skin between tergite and sternite lack pigment.
Venezuela costal region-Trinidad: Black body, black antenna, dark yellow leg with red-brown wrings, terminal tergite have a "hump" which can be view as enlarge keel if you want to, skin between tergite and sternite fully pigmented being black. However individuals lacking wrings do appear.
Northern Peru: Red body with slightly darker front edge, yellow legs, terminal tergite lack any keel or hump, skin between tergite and sternite lack pigment.
Venezuela inland region: Whole pale body with no pigment at all.

Besides that, by rough view all characteristic looks very similar, but take deeper view there are many differences which bugs me quite a lot. And due to the fact I do not have access to the neotype of S.gigantea I won't be saying which one is the real "S.gigantea" but just point out the difference I see.

1.Glabrous antenna segments: I count 7~9 on my Peruvian, 9 on both of my Trinidadian, and 9~10 from online photo of Isle Aruba population.
2.Toothplates: Peruvian's inner 3 tooh almost merge together, while the other 2 populations can identify 4+4 easily. Base of Trinidadian population are much wider than other 2 reaching 1/3 of coxosternum, other's roughly reach 1/4.
3.Margination: Margination all begins from tergite 4, but Isle Aruba and Trinidadian only reach 1/3 on the 1st and Peruvian easily reach over half of the length.
4.Paramedian sutures: Trinidadian population lack sternites while both Peruvian and Isle Aruba population have this characteristic, one of my Trinidadian only have them from tergite 3~19 but another count from 3~20, 3~20 on all my Peruvian and all Isle Aruba population photo I can find.
5.Prefemur: Prefemur 20 all have 5 spikes on 3 populations, but Trinidadian arranged being 2-3, and the other 2 arranged being 1-4.
6.Prefemur of terminal legs: Differs so much...
6.1 Both of my Trinidadian only have either 4 or 5 spikes view from the bottom arranged in either 3-2 or 3-1, My Peruvian count minimum 4-3 up to 5-4, Isle Aruba count 4-3 from the only pic I can find.
6.2 Inard side of the leg, Trinidadian have only 1 or 2 spikes and both Peruvian and Isle Aruba population got 2 rolls arranged in 3-4 with ocaationaly very small spot.
6.3 On the dorsal side, arrangement all looks smiliar but Trinidadian have much larger spikes.
6.4 Trinidadian have much more spikes in the terminal cluster, on one of my pedes' leg counts 11, minimum counts 7(plus a small dot), on the other 2 populations all counts between 4-6.
7.Terminal tergite: This is the odd part, on all characteristics Trinidadian seemed to looks more different from the other 2, but this time, lacking humps Peruvian being the strange one which differs.
8.Leg ratio: Peruvian have much tinner and longer legs, terminal legs' prefemur can reach 1.5x of terminal tergite's length while the other 2 only reach 1.2 maximum. Trinidadian's legs are significantly shorter and thicker than others.
9.Trinidadian population and Venezulan inland population have much larger head than others judge from photo and measurement from my individauls, but since this characteristic are highly effected by animals' age I won't call it a valid ID key ATM.
10.Trochanteroprefemur: Trochanteroprefemur spikes extended much forward on Trinidadian population.

Again, since I don't have access to the neotype of S.gigantea I won't judge which one is the "real" gigantea or any of them "not", but IMO this 3 populations are very likely to be different species, especially the Peruvian one being seperated by 1.Andes 2.Amazon basin from the other 3 known population.
 

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RTTB

Arachnoprince
Joined
Dec 4, 2016
Messages
1,765
I found that to be very interesting and informative.
 

Staehilomyces

Arachnoprince
Joined
Mar 2, 2016
Messages
1,447
I looked up the Aruba variant. Cool looking pedes! I actually think I remember that colour variant being featured in that deadly 60 show.
 
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