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his month of September 2012 welcomes back again, Asian Catfish expert Adrian Taylor of the Catfish Study Group to look at a small hillstream catfish of the Akysidae family, Parakysis verrucosas. Now over to Adrian.

Members 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 verrucosus

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.

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Parakysinae

Asia: Malay Peninsula, through to the Greater Sunda Isles; of Borneo, Indonesia and Sumatra.

5.0cm. (2ins)

19-23°C (65-73°F)

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.

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 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.

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.

Adipose fin: Fleshy finlike projection without rays, behind the rayed dorsal fin.
Dorsum: The upper (dorsal) surface of the head or body.

Parakysis: Greek, para = the side of + Greek, kysthos = bladder.

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.
Taylor, Adrian. pers. comm.

Photo Credits

© Adrian Taylor