Margot Robbie caught a huge amberjack during a trip to San Juan del Sur, Nicaragua, this week. The actress also shared photos while surfing and doing "sunset pool yoga," something that she tweeted will eventually "catch on."

Quoting Bruce the Shark's classic line from "Finding Nemo," Margo captioned the photo from her Earth Day fishing excursion, "Fish are friends not food!"

After a few minutes of staring at Margot in her sexy bikini we finally noticed the fish.

The Wolf of Wall Street is just one of several stars who posted sexy shots to Instagram this week.

Rihanna hit the beach last Sunday, wearing a mesh one-piece with marijuana leaf designs to hide her modesty. The date: 4/20, of course.

Model Doutzen Kroes wished everyone a Happy Easter with a topless shot, Paris Hilton took a dip and Michelle Rodriguez did a headstand next to a sports car.

Also: Katherine Webb filled in on TV's "Extra" (she's rumored to be replacing Maria Menounos), and James Franco shared a photo in bed with pal Keegan Allen.

Models Bar Refaeli and Candice Swanepole shared photos of their bodies in bikinis from a specific point of view and "Big Bang Theory" star Kaley Cuoco showed off her new haircut.

See them all and more in this week's Celeb Instagrams.