Post by rainbowfish on Dec 17, 2019 22:29:15 GMT -6
A few days ago (December 12th 2019) someone asked if these two species were the same. Heiko the collector responded that yes they were. I think this sometimes happens when you collect too many different fish! PSEUDOMUGIL species Aru II and Aru IV are definitely one and the same species. All of the Pseudomugil experts in Europe that kept them cannot see any difference nor could I. HOWEVER, for the MELANOTAENIA sp Aru IV and Aru II there are major differences, both meristic and with DNA samples that HEIKO submitted. I hope that Heiko will go back over his notes and realize that yes these Melanotaenia sp fish indeed are two different species. It’s the Pseudomugil that are the same. For live video of the two fish I would suggest that you go to Cory’s CO-Op and look for the video that he did of my fish room. It’s probably the best edited and produced video out there on my fishroom. I haven’t seen it in a while but I am pretty confident that both fish made it on the video as they were of good size then.
As you can see from Peter’s DNA tree there are two samples that Heiko submitted to him. One labeled Aru II and one labeled Aru IV. Unfortunately those samples were reversed as the Aru II fish looks and acts much more like a trifasciata, not like the member of the goldiei tribe. I also remember Peter telling me that the Aru II sample that I submitted fit into the trifasciata tribe. So first we were dealing with two very different fish. – See photo here of the Melanotaenia picta aquarium photo that was used in the description. Then look at the photos below of my picta and you can see the same basic color patterns.
As many of you know the Melanotaenia species Aru II was given a name a few years ago. It is officially been named Melanotaenia picta. Aqua, International Journal of Ichthyology Rainbowfishes “(Melanotaenia: Melanotaeniidae) of the Aru Islands, Indonesia with descriptions of five new species and redescription of M. patoti Weber and M. senckenbergianus Weber”. Gerald R. Allen, Renny K. Hadiaty, Peter J. Unmack, and Mark V. Erdmann. March 8, 2015. Aqua vol. 21 no. 2 - 15 April 2015. In the description of Melanotaenia picta Allen points out that it is a much more slender fish than several others that they collected on this trip. That is exactly what you see when you compare the two. Below you will see photos that I’ve taken from 2010 of the two fish. I brought those fish back from Europe in June of 2009 so they were still relatively young. Melanotaenia picta (Aru II) January 15, 2010 and Aru IV March 10th March 31, 2010. Later photos of picta (Aru II) were from February 11th, 2014. Photos of Aru IV from September 2, 2013. At one time the Europeans jumped the gun and labeled this Aru IV as senckenbergianus which from the paper turned out to be incorrect. There may still be some of these incorrectly named floating around in Europe and maybe now in the United States. As far as I know this fish wasn’t brought back and reproduced but maybe someone else has some further information.
Like other fish from the “goldiei tribe” the Aru IV fish is quite broad, that is tall from dorsal to anal fin. The picta is much more streamlined. Anyone that saw these two fish as full size adults in the flesh or swimming in a video would not mistake one for the other.
I realize that Hans Evers mentioned on FB that he also thought the two fish were the same then after thinking about it realized that wasn’t right. Jet lag will do that to you!
Anyway there you have it, Melanotaenia species Aru IV and Aru II (now Melanotaenia picta) are two different species.