If I was a shop owner of an aquatics shop I would be looking for a person with the following:
Experience in keeping fish themselves
A general knowledge about plants, medications, food, filters and other dry goods.
Someone who has experience dealing with the public - patience, tolerance and can relate well to all nationalities, age groups and experience levels
A person who is prepared to do manual tasks ie tank cleaning, shop cleaning - dusting etc
A person who has an eye for details
A person who has had some form of retail experience