Scientists have described six new species from the Siamese fighting fish genus, Betta.
All of the fishes have been described from the freshwaters of Borneo and five of them have previously been sold in the aquarium trade.
The fish have just been named as Betta antoni, B. mandor, B. uberis, B. compuncta, B. ideii and B. krataios by Heok Hui Tan and Peter Ng of the Department of Biological Sciences at National University of Singapore in the journal Ichthyological Exploration of Freshwaters.
Three of the new Betta, B. antoni, B. krataios and B. mandor, were found in the Kapuas River basin at Kalimantan Barat. Betta uberis was found in Kalimantan Tengah, Betta ideii was found at Kalimantan Selatan, while Betta compuncta was discovered recently on an expedition to Kalimantan Timur. The latter is believed to be a close relative of B. pallifi, which was recently discovered in Kalimantan Tengah.
Tan and Ng say that Betta antoni is a member of the akarensis group and is distinguished by its black lower lip and black chin bar, and slim body profile.
Betta mandor is a member of the foerschi group and can be identified by its slim shape and presence of two red bars on the gill cover.
Betta krataios is believed to be a member of the Betta dimidiata group and has a distinctive iridescent blue operculum, and more predorsal and lateral scales than other members of the group, as well as lacking the extended fin rays seen in some other species in the complex.
Betta ideii differs from other species in the Betta unimaculata group in having a characteristic orange marking between the front of the eye and the upper jaw. Betta compuncta is also a member of the unimaculata group and has a distinctive black reticulated pattern above the base of the anal fins of females and young fish, or a black patch in males. There's also a yellow-orange marking on the tail of females of this species.
Betta uberis is a member of the coccina group and has distinctive green streaks on the dorsal, anal and tail fins as well as an iridescent green mid-lateral spot, which is seen in most members of the species group.
For more details on the new Bettas see the paper: Tan, HH and P Ng (2006) - Six new species of fighting fish (Telestei: Osphronemidae: Betta) from Borneo. Ichthyological Exploration of Freshwaters. Vol. 17. No. 2. pp. 97-114.