The different Indonesian Arowanas varieties are distinct species based on genetics.

[SGdiscus]

Hi all, I came across this article ( https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers19-11/010033034.pdf ) that describes the differences between an Indonesian Green, Indonesian Silver (or Yellow Tail), Super Red and Red Tail Golden. Very heavy reading. I read it a few times and still cannot fully comprehend. There are some interesting takeaways:

1. Indonesian Green (S. formosus) can be found in the wild in both Sumatra and Borneo.

2. Indonesian Silver/Yellow Tail (S. macrocephalus) can be found in the wild in Borneo.

3. Indonesian Super Red (S. legendrei) can be found in the wild in Borneo.

4. Indonesian Red Tail Golden (S. aureus) can be found in the wild in Sumatra.

5. The study, based on the specimens collected, found that Banjar Red is the result of females Silver/Yellow Tail and males Super Red.

6. The study did not mention hybridization of Indonesian RTG and Malaysian Crossback (there are also a few articles on the genome sequencing of Malaysian Crossbacks) as it was focused only on arowanas collected in Indonesia. If I come across a research paper that differentiates a Malaysian Crossback and an Indonesian RTG, I will share it here.

Maybe the knowledge above are common market knowledge for the more experienced keepers. I thought it was relatively interesting for a new aro keeper like myself to understand it from a researched angle. I am not saying that the research is 100% correct since the number of specimen collected is limited. I found it interesting neverthless.

For your pleasure reading!

 

[Caveden]

Nice

 

[tetroid]

That study came out in 2003, but it was never really accepted in the scientific community as sufficient for establishing any new arowana species. Like you say, they didn't gather many samples. They probably should have focused on just one or two potential species and taken lots of samples. It's certainly an interesting read, though. Further study may result in at least some of the species proposed in that article being declared valid. The super red (scleropages legendrei) always seemed to me like it should be considered a separate species. Lots of differences other than colour.

Anyway, here's a pretty good rundown from someone's formal application to the Australian government to let them import Asian arowana.

S. formosus exhibits multiple colour variations and combinations consisting of reds, greens, blues and gold’s. These variations have since been classified as the species S. legendrei, S. macrophalus and S. aureus, by Pouyaud et al. (2003, Figure 1 – 4). Although appearing to be of different colours, these varieties are considered one species by Kottelat and Widjanarti (2005) because they can crossbreed with one another (Goh and Chua 1999) and produce viable hybrids with colouration traits from both parents (Chang Kuok Weai Alex 2010, Figures 5). In order for more than one species to be recognised as proposed by Roberts (2012) and Pouyaud et al. (2003), a professional standard study would need to be presented (IUCN 20111 ). However, so far, there are relatively few scientific papers being published about the species in peer-reviewed journals (Yue et al. 2006). More still needs to be done to resolve the confusion in species determination.

 

[SGdiscus]

That study came out in 2003, but it was never really accepted in the scientific community as sufficient for establishing any new arowana species. Like you say, they didn't gather many samples. They probably should have focused on just one or two potential species and taken lots of samples. It's certainly an interesting read, though. Further study may result in at least some of the species proposed in that article being declared valid. The super red (scleropages legendrei) always seemed to me like it should be considered a separate species. Lots of differences other than colour.

Anyway, here's a pretty good rundown from someone's formal application to the Australian government to let them import Asian arowana.

Wow! Thank you for sharing. I read the formal application - it is really well written and it also put together all the relevant research into 1 document. Nice!