DYBOWSKI erected the genus Squalidus in 1872 in monotypy describing Squalidus chankaensis Dybowski, 1872 from the Amur River basin as the type species. Currently (November 2008) there are 16 valid species and subspecies allocated in the genus Squalidus. Squalidus wolterstorffi was originally described as Gobio wolterstorffi by Regan in 1908. Later in the 1980s it was placed in the genus Squalidus.
Squalidus wolterstorffi (Regan, 1908)
Taxonomy - Identification - Distribution & Habitat - Maintenance
Squalidus wolterstorffi belongs to the subfamily Gobioninae. Gobionine fishes are widely unknown to aquarists.
CHEN et al (1998) provides an English key to the Squalidus species occurring in China, which is easily accessible in the internet at FishBase. Thus I refrain from a detailed description. FishBase propagates a TL of 86 mm, my preserved specimen has a SL of 34 mm. Although I did keep it for some months, it did not grow bigger. HUANG, CHENG & LE (1988), who show the only (!) picture of this species in literature (identical with the picture displayed at FishBase), state a length up to 100 mm.
Distributional range and biotope
Squalidus wolterstorffi seems to be wide spread over China. There are reliable reports from Beijing, Hebei, Shandong, Zhejiang, Fujian, Guangdong, Guangxi, Sechuan and from Hainan Island, from the following basins; Yangze (Changjiang River), Yellow River (Huanghe River), Zhujiang River, Mingjiang River, Hongshuihe River, Guijiang River, Youjiang River, Zuo Jiang River, Liujiang River, Lijiang River and Fuchunjiang River. Analyzing all these water systems you might be tempted to say that Squalidus wolterstorffi is omnipresent in almost all provinces of China with temperate to subtropical climate. It is lacking in the northern provinces, it also should be absent in the Amur basin (Heilongjiang River).
Squalidus wolterstorffi belongs to the subfamily Gobioninae. Gobionine fishes are widely unknown to aquarists.
Squalidus wolterstorffi inhabits the benthopelagic of broader rivers and lakes.
According to HUANG, CHENG & LE (1988) Squalidus wolterstorffi inhabits rivers and streams. This fits to the environment I caught my fish in; EZ-CN 30-06 at Shao Ji Wan (筲箕湾) in Zhejiang province, SE-China. This biotope is a broad river (50 m) with comparatively low water level. The water was very clear and had the following parameters:
- Temperature 33 ºC
- pH 8.8
- Conductivity 71 µS/cm
- Total hardness 2 ºGH
- Carbonate hardness 2 ºGH
I caught Squalidus wolterstorffi sympatric with Acrossocheilus labiatus, Opsariichthys bidens, Zacco platypus, Rhinogobius sp. "Striped Belly" and a non identified member of flat loaches, family Balitoridae (not caught). Unfortunately I could just catch one specimen. We arrived at this fishing spot very late on a Sunday and had to turn back to Shanghai. Therefore our time was limited.
I do not know any publication about Squalidus wolterstorffi ‘s aquarium maintenance, thus I decided to write this short essay. Unfortunately I just kept one specimen. Thus my experiences might be not representative.
When we arrived late in the night in Shanghai Pudong I immediately introduced all fishes in different tanks which had been prepared in advance. I had some doubts if the Squalidus will make it, since its morphology looks a little fragile. The next weeks proved that it is actually rather hardy. In addition, I never had any problems with diseases during the maintenance.
Squalidus wolterstorffi make a very peaceful tank mate. There were no aggressions against other inhabitants in the community tank. It is benthopelagic and is steadily foraging for food on the ground level. Food items flowing on the water surface are ignored. While foraging it uses it barbels as antennas extended front down wards. Only the posteriormost end of the barbels is bending backwards due to the water pressure when swimming. The barbel’s rest is stiff and remains extended when foraging. When not on the hunt for food, the barbels are not extended, but folded next to the head. Squalidus wolterstorffi is omnivorous and actually feed upon everything, which can be swallowed. The mouth is quite small; the fish keeper should pay attention to that when feeding. There is a preference for Tubifex.
The fish tank should possess an appropriate filtration featuring a low to moderate current of bacteriological proper and clear water.
Marco Endruweit, 2008-11-01
Squalidus wolterstorffi seem to be an ideal addition to stream setup tank.
