Chapter 12 Tropical freshwater fish
Around 80–90% of tropical freshwater fish are captive bred, with typical hot spots of production being Singapore (e.g. Fig. 12.1), Malaysia, Israel, Florida and the Czech and Slovak Republics. Some important fish to the industry are still wild-caught however, such as the cardinal tetra (Paracheirodon axelrodi) from the Amazon basin.
Recommended water quality parameters for different aquariums are listed in Table 12.1. Water hardness is measured in a variety of different ways with mg CaCO3 as international standard. Conversion factors from other units are given in Table 12.2. Common species of tropical freshwater fish presented to the veterinarian are listed in Table 12.3.
|Unit||Conversion factor to (mg CaCO3)|
|Benzalkonium chloride concentration (mg/L)||Duration of bath (min)|
|pH||Concentration in soft water (mg/L)||Concentration in hard water (mg/L)|
Note that many freshwater fish can utilize atmospheric air. Lungfish (Protopterus spp) anabantids (including the popular gouramies (Trichogaster spp), fighting fish (Betta spp) and paradisefish (Macropodus spp)) and some South American catfish such as Hypostomus punctatus and corydoras are common examples. Gulping for air in these species may not necessarily indicate a respiratory problem.