Sarcocheilichthys parvus Nichols, 1930

This article is taken from the BSSW-Report 01-2022

The genus Sarcocheilichthys comprises around ten species that are endemic to eastern Asia (Japan, Korea, Vietnam and especially China) and are found in cooler rivers, streams and lakes, where they mainly live on stony and rocky ground. S. parvus originates from the Chinese provinces of Fujian, Guangxi, Guizhou, Jiangxi and Zhejiang. The distribution area and the well-studied diversity of the genus make the species popular objects of research in relation to speciation in connection with geological activities in the past. Sarcocheilichthys spp. are also popular indicator species for the condition of water bodies, as they are dependent on largely unpolluted water. (Zhang et al. 2008). The genome of S. parvus has also been completely sequenced (Chen et al. 2013).
It is known from nature that mainly aquatic invertebrates and algae serve as food (Zhang et al. 2008). This corresponds to the typical diet of benthic fish, albeit only very vaguely described, as can be expected from such a habitat.

The only German literature source on the species known to me is a brief introduction by Hans-Georg Evers (2005), who received a single specimen at the time and found it to be ‘quite peaceful’, at least in the company of Tanichthys albonubes. This was also my impression from observing a small group for a few hours. The S. parvus were far too busy with their own hustle and bustle to even notice the dwarf cichlids in the same tank. My observations were interrupted from time to time and are by no means conclusive enough to generalise the species here as peaceful, but there is almost no literature on the species, which is why they are mentioned. Nichols (1943) gives males with a length (SL) of 70 mm, females with 57 mm. The total length should therefore be 90 to 100 mm, which would speak in favour of a species that remains small and is well suited to aquaristics, especially as the required water parameters in an unheated tank do not pose any problems and feeding is also easy to manage. There are considerably more reports on S. parvus in the Chinese hobby literature and corresponding internet forums, which also report easy care. Only reproduction is somewhat more complicated, as the eggs are placed by the female in the mantle opening of freshwater mussels during the spawning cycle (Bănărescu & Nalbant, 1973; Luo et al., 1977). This makes reproduction in the aquarium somewhat more difficult, but not impossible, as the strategy is also known from the bitterling (Rhodeus amarus) and is also successful in the aquarium. It is only conceivable that S. parvus favours a certain type of mussel and does not accept European river mussels (Unio crassus) as a spawning substrate, for example.

I didn’t have to travel to Guangxi to see my first S. parvus, but was able to observe and photograph them in the ‘Zierfischtreff’ of Hubert Schmalzbauer (Theilenhofen), whom I would like to thank for this and for his great fish.

Text and picture: Daniel Konn-Vetterlein

Literature:

Bănărescu, P. & Nalbant, T. T. (1973): Pisces Teleostei Cyprinidae (Gobioninae). Berlin:Walter de Gruyter.

Chen X., Zhou Z., Chen Z, & AI W. (2013): Complete mitochondrial genome of Sarcocheilichthys parvus (Cypriniformes, Cyprinidae). Mitochondrial DNA, (2013) 24(2): 97–98

Evers, H. G. (2005): Sarcocheilichthys parvus aus China, Amazonas Magazin, (2005) 2, S. 68

Nichols, J. T. (1930): Some Chinese freshwater fishes. XXIV. Two new Mandarin fishes. XXV. New Sarcocheilichthys in northeastern Kiangsi. American Museum Novitates No. 431: 1-6.

Nichols, J.T., 1943. The freshwater fishes of China. Natural history of Central Asia: Volume IX. The American Museum of Natural History, New York, USA, 322 p.

Zhang L., Tang Q. T. & Liu H. Z. (2008): Phylogeny and speciation of the eastern Asian cyprinid genus Sarcocheilichthys. Journal of Fish Biology (2008) 72, 1122–1137