Joseph Duggar is back in Florida, where he will face child sex abuse allegations made against him ... and we've obtained the new mug shot authorities took of him.

The former reality TV star was booked into the Bay County Sheriff's Office Tuesday morning ... and the new photo shows his hair and beard have seemingly grown a bit since he was taken into custody in Arkansas earlier this month.

Duggar's still parting his hair the same way -- a long swoop splitting the middle of his forehead -- and he seems to have a small smile on his face in the pic. Page Six was first to report on the new mug.

As you know .... Duggar was arrested in Arkansas and charged with lewd and lascivious behavior, involving unlawful sexual activity with a minor, after a girl reported an incident to the police, she claims went down in 2020 when she was just 9-years-old.

The alleged victim has accused Duggar of touching her inappropriately ... and cops claim he "manipulated the victim's underwear and grazed her genitals."

Shortly after his arrest, his wife, Kendra Duggar, was also arrested. They were both charged with 4 counts of second-degree endangering the welfare of a minor and 4 counts of second-degree false imprisonment. These charges are not related to the child sex abuse charge Duggar is facing in Florida.

Multiple of Joseph's family members -- like his sister Jinger Duggar and his cousin Amy Duggar King -- have come out and condemned him in the aftermath of his arrest. His brother Josh Duggar, who is serving prison time after he was convicted on child pornography charges in 2021, said through a lawyer he's standing with Joseph.

Story developing ...