Rungan, Central Kalimantan - some interesting Siluridae

[panaque]

I have just returned from an expedition into forest in between the Rungan and Kahayan rivers in Central Kalimantan (Indonesian Borneo) where I carried out a fish survey of forest streams and swamps. There were some interesting Siluridae:

Kryptopterus macrocephalus

? [EDIT: confirmed]

Another

Kryptopterus

sp.? (largest specimen 48mm SL) [EDIT: Likely

Ompok weberi

]

and look at this iridescent blue one (dorsal profile indicates that this is not the Blue Sheatfish

Kryptopterus cryptopterus

). These are actually very similar to first one above but those really showed no sign of colour. [EDIT: Likely either variant of

Kryptopterus macrocephalus

or in same species complex]

Silurichthys phaiosoma

The four species above all came from large pools (5m wide, 2m deep) in the main stream draining the area. The one below only appears to occur in isolated residual pools of small streams (<1m wide, <50cm deep)

Silurichthys

sp.?

[BomNya]

Hey Panaque, cool pics. Did you happen to find any Garra whilst there?

[panaque]

Hey Panaque, cool pics. Did you happen to find any Garra whilst there?

No Garra. These are black waters over peat/sand substrates so not your typical Garra habitat. The nearest things are 3 species of Osteochilus:

O. spilurus

O. bleekeri

O. pentalineatus

[panaque]

@silurus, any thoughts on ID of species in first post? The blue Kryptopterus and small Silurichthys with evenly forked tail (I've seen 9 specimens, all of similar size) in particular...

[Silurus]

Blue Kryptopterus looks like K. macrocephalus to me, but I think what is currently identified as K. macrocephalus may be a species complex. Second silurid is Ompok weberi (a species that does not grow large). Last Silurichthys is likely S. gibbiceps.

[panaque]

Blue Kryptopterus looks like K. macrocephalus to me, but I think what is currently identified as K. macrocephalus may be a species complex. Second silurid is Ompok weberi (a species that does not grow large). Last Silurichthys is likely S. gibbiceps.

Many thanks @Silurus. I'm not sure about the last Silurichthys though as S. gibbiceps should have a marmorated pattern and 47-54 anal fin rays and I count only 38 in the specimen in my photo. What do you think?

@Jools feel free to use any of the photos in this post for the cat e-log (e.g. Ompok weberi entry does not have image yet)

[Silurus]

Not S. gibbiceps then. Maybe S. marmoratus, but the fewest anal-fin rays I have seen in this species is 44. Thirty-eight is a very low number for any Silurichthys.