Parakysis verrucosus
Herre 1940 |
This month of September 2012 welcomes back
again, Asian Catfish expert Adrian Taylor of the Catfish Study
Group and webmaster of asiancatfish.com, to
look at a small hillstream catfish of the Akysidae
family, Parakysis
verrucosas. Now over to Adrian.
embers of the genera Parakysis are at the moment few
in number, with only 6 species making up this genus. Their range
seems to be restricted to the Malay Peninsula, through to the
Greater Sunda Isles; of Borneo, Indonesia and Sumatra.
Parakysis
can easily be distinguished from the species that make up the
genera Akysis and Pseudobagarius as they do
not possess an adipose fin as such; having only what is called
an adipose ridge, which can at times be hard to distinguish as
it is shallow and runs along the median of the dorsum surface.
|
Parakysis
verrucosus -
dorsal view |
Parakysis verrucosus although
preferring cool temperatures of around 19°C to 23°C will
tolerate warmer temperatures as long as attention is paid to water
quality and has a high oxygen content. Water having pH values
of between 6.7 and 7.2 should be provided, as these small ‘stream
cats’ tend not to tolerate for any length of time p.H values
that fall outside this range.
An aquarium having a gravel substrate and
containing areas of pebbles, small rocks and a scattering of small
grass like plants would make an ideal set up for these little
hillstream catfishes.
P. verrucosus has a narrow head
with small, subcutaneous eyes. The upper lip has a median lobe projecting
into a median concavity on the lower lip. There are 1-2 branches
on the outer mandibular barbel. The inner mandibular barbel has
2-3 long, thin branches; the first 2 are almost always joined at
the base. The mandibular latero-sensory canal has a pore lateral
to the inner and outer mandibular barbels. Body tubercles are small.
The dorsal fin has 1 spine and 4 rays; the first 2-3 rays are simple,
the last 1-2 rays are branched. The pectoral fin has 1 spine and
5-6 rays; the innermost ray is sometimes branched; the 4-5 median
rays are branched, and the outermost ray is sometimes simple. The
pelvic fin has 5-6 rays; the first ray is simple, the 3-4 median
rays are branched, and the last 2 rays are simple. The anal fin
has 8-10 rays; the first 5-6 rays are simple, the last 2-5 rays
are branched. The caudal fin has 12-13 rays; the uppermost and lowermost
principal rays are simple, the 10-11 median rays are branched.
Ruddy brown coloured ‘stream catfish’
having ochre coloured granulations (raised spots) that run horizontally
along its body and the ventral surface being ochre to light lemon
in colouration. The barbels are barred with brown and ochre colouration.
Fish such as Brachydanio rosaeus and
Barbus rhombocellatus would make excellent tank companions
for these small, but somewhat inconspicuous members of the Akysidae
family.
As yet there are no reports of any Parakysis
breeding success’s in the home aquarium; although, it may
well be that they spawn similarly to Akysis vespa as reported
upon by H H Ng & M Kottelat in their 2004 scientific paper on
Akysis vespa.
| Sexual
differences |
Sexual dimorphism is
hard to discern, but it is thought that the females maybe
wider in the ventral area than the males when they are in
optimum spawning condition.
|
| Diet |
A diet of live foods such as: Daphnia,
Cyclops, small bloodworms and white worms should be offered, as
like most of the sub-family ‘Parakysinae’, Parakysis
verrucosus tends not to feed upon commercially prepared dried
foods; although they will accept small frozen bloodworms.
| Etymology |
Parakysis:
Greek, para = the side of + Greek, kysthos = bladder
|
| References |
www.asiancatfish.com
Ng, H. H. and K. K. P. Lim.
1995. A revision of the southeast Asian catfish genus Parakysis
(Teleostei: Akysidae), with descriptions of two new species.
Ichthyological Exploration of Freshwaters 6 (3): 255-266.
Ng, H. H. and M. Kottelat.
2003. Parakysis notialis, a new species of akysid catfish
from Borneo (Siluriformes: Akysidae). Ichthyological Research
50: 48-51.
|
| Glossary
of Terms |
Adipose fin:
Fleshy finlike projection without rays, behind the rayed
dorsal fin.
Dorsum:
The upper (dorsal) surface of the head or body.
|
©
Adrian Taylor |
