Hi all i just bought a gold nugget pleco,Is it normal for him to appear shy at first he's found a cave and been in there all day looking out at me

also will he eat the algae from the front and sides of the tank like my common pleco does ? and one more question as he is only about a inch and half would he be okay in with a larger common pleco ? (about 9 inches)
Thanks in advance ppl
