Goji is one month old. Is he too skinny?

Goji is one month old. Is he too skinny?

Goji hatched on November 4th and hes a really good eater and hes been growing so fast, but during some moments, he looks incredibly skinny and i can count all of his ribs…is he okay? Is there anything i can do to help him eat more? Hes on fruit flies and pinheads right now and he has live plants in his enclosure, nothing plastic. He gets misted 3-4 times a day. Also i know hes too young to really know what gender he is but hes got a lot of colors coming in which lead me to believe hes male. Am i right to assume so?