CBS has announced the identities of the 18 castaways who will be competing on Survivor: One World, the 24th Survivor edition that will premiere Wednesday, February 15 at 8PM ET/PT.

As the network previously announced, Survivor: One World will -- in a Survivor first -- feature a twist in which the competition will begin with the castaways divided into two tribes that will live on the same beach.

"Once again, Survivor is changing things up. This time, two tribes will compete against each other while living together on one island," Survivor host Jeff Probst announced during last month's broadcast of Survivor: South Pacific's reunion show.

"They'll have to decide whether to share their resources or leave the other tribe to fend for themselves as they battle it out... Two tribes! One world! One Survivor!"

In addition to living together, the tribes of Survivor: One World will be divided by gender, with the nine male castaways competing as the Manono tribe and the nine female castaways forming the Salani tribe. Both tribes take their names from local islands.

Survivor: One World was filmed back-to-back with Survivor: South Pacific in Samoa last summer. Samoa also previously served as the filming location of Survivor: Samoa and Survivor: Heroes vs. Villains when they were filmed back-to-back in Summer 2009.

The nine members of the all-male Manono tribe are:

- Jay Byars, a 25-year-old model from Gaffney, SC

- Colton Cumbie, a 21-year-old college student from Monroeville, AK

- Michael Jefferson, a 30-year-old banker from Seattle, WA

- Leif Manson, a 27-year-old phlebotomist from San Diego, CA

- Jonas Otsuji, a 37-year-old sushi chef from Lehi, Utah

- Bill Posley, a 28-year-old stand-up comedian from Venice, CA

- Matt Quinlan, a 33-year-old attorney from San Francisco, CA

- Troy Robertson, a 50-year-old swimsuit photographer from Miami, FL

- Greg Smith, a 64-year-old plastic surgeon from Houston, TX

The nine members of the all-female Salani tribe are:

- Nina Acosta, a 51-year-old retired LAPD officer from Clovis, CA

- Christina Cha, a 29-year-old career consultant from West Hollywood, CA

- Monica Culpepper, a 41-year-old ex-NFL football player's wife from Tampa, FL

- Kat Edorsson, a 22-year-old timeshare representative from Orlando, FL

- Chelsea Meissner, a 26-year-old in medical sales from Charleston, SC

- Kourtney Moon, a 29-year-old in motorcycle repair from Austin, TX

- Alicia Rosa, a 25-year-old special education teacher from Chicago, IL

- Kim Spradlin, a 29-year-old bridal shop owner from San Antonio, TX

- Sabrina Thompson, a 33-year-old high school teacher from Brooklyn, NY