i intend to buy some Corydoras paleatus to put in my aqurium with a male betta (crowntail betta) and i do not have an air pump ... does Corydoras paleatus need air pump ???
I would not suggest keeping any corys in an unfiltered tank so if not having an air pump means that there will be no filtration, please do not get them.
Also, what is the size of your tank? C. paleatus is one of the larger corys; they get up to 4" long. Like all corys they are schooling fish and should be kept in groups of 3 or more. Is your tank large enough to accommodate them? If not, there are other smaller corys that might be a better choice for you.
Please do not keep corys and a betta in an unfiltered tank unless you are prepared to do BIG water changes and bottom cleanings EVERY DAY.
Both cory cats and bettas are highly prone to getting finrot, which is a bacterial infection. If that water in the tank is unfiltered and not circulating, it will rapidly become stagnant. This is a condition that allows the bacteria that caused these diseases to thrive.
Please get your pump going and make sure that your tank is cycled before adding corys.