Discovery’s famous Shark Week officially kicked off Sunday, and programming continues in earnest today, starting with “Sharkzilla: Sharktweeto” (Discovery at 8 p.m.), which looks at a prehistoric mega-shark. Later, “Return of Jaws” (at 9) looks back at a shark attack in Massachusetts.

FINALE WATCH: After the shocker last week — final three contender Brooks unexpectedly left the show, leaving Desiree in tears — Desiree decides whether she wants to move forward with one of the last two guys, Chris and Drew, on the season finale of “The Bachelorette” (ABC at 8). Post-finale, Des (along with Chris, Drew and that troublemaker, Brooks) return to discuss the twists and turns of the season on “After the Final Rose” (at 10), as Chris Harrison grills everyone about what really went on.

Lots of behind-the-scenes types are overlooked in Hollywood, but one of the most egregious? Casting directors. Documentary “Casting By” (HBO at 9) profiles casting experts Marion Dougherty and Lynn Stalmaster, who were blessed with the skill of spotting talent. Dougherty is credited with kick-starting the careers of Glenn Close, Robert Redford, James Dean and others.

RETURNING SHOW: “T.I. & Tiny: The Family Hustle” (VH1 at 9), starring rapper T.I. and his wife, Tameka “Tiny” Harris, and their six kids, is back for a fourth season as T.I. tries to convince his 13-year-old son it’s time to start dating.

RETURNING SHOW: There’s lots of drama going on with Jayceon Taylor (rapper “The Game”) and his fiancee, Tiffney Cambridge, but they let the cameras in for all of it on the Season 2 opener of “Marrying the Game” (VH1 at 9:30). Although the two are living separately after Tiffney called off the wedding, they still must co-parent their two children, Cali Dream, 2, and King Justice, 6.

SERIES PREMIERE: New series “Deep Fried Masters” (Destination America at 10) goes around the country to state fairs to find the best fry cooks, and starts in North Carolina as the contestants deep-fry everything from macaroni and cheese to pizza.

It’s the circle of life on “Under the Dome” (CBS at 10), as a baby is born at the same time another dome resident meets an unfortunate end.

“The Tonight Show With Jay Leno” (NBC at 11:35) hosts actor Bryan Cranston, model Karolina Kurkova and singer Amos Lee.

Actress Sharon Stone and comedian Dane Cook are on “Jimmy Kimmel Live” (ABC at 11:35), along with a performance by Jamie N Commons.

— Emily Yahr