These are only recommendations and it's all about the source of information. The golden dwarf moray can be completely happy in something as small as a 30g, while some have even kept them in 20g. They rarely open swim and are not aggressive, mostly will find a spot or 2 and just tuck away. Those other tank recommendation for eels such as the 2' fangtooths are greatly understated, they need much larger tanks. The snowflake needs a larger tank than many recommend as well, this is about selling fish, snowflakes are so common they lie.
