Coach Stephen Betham has included six players who missed the recent Pacific Nations Cup (PNC), where Samoa were beaten by Fiji in the final, including Leicester Tigers prop Logovi'i Mulipola.
Wellington Hurricanes midfielder Rey Lee-Lo and the Pisi brothers -- Tusi (Suntory Sungoliath), George and Ken (both Northampton Saints) -- also make the squad after missing the PNC.
Treviranus, 31, returns to the squad after a neck injury suffered in Samoa's historic home Test against New Zealand last month.
Betham said that despite losing to Fiji in the final of the PNC, the tournament proved invaluable in settling on his World Cup squad.
“The task was to test our depth and to give players an opportunity to rise to the occasion. Some obviously did, and some weren't quite strong enough to unseat the established professional players in their positions.”
Three locally-based players, prop Jake Grey, scrum-half Vavao Afemai and fly-half Patrick Faapale, all did enough in the Pacific Nations Cup to earn selection ahead of strong competition from overseas-based professional players.
Betham said former captain and wing David Lemi, prop James Johnston and scrum-half Pele Cowley were not available because of injury.
The team announcement made no reference to the absence of veteran front-rower Census Johnston who played for Samoa against the All Blacks last month despite his contract with Toulouse stipulating an end to his Test career.
Other notable names missing from the list included flanker Faifili Levave and outside backs Sinoti Sinoti, Paul Williams and Ah See Tuala.
“This has been an incredibly difficult selection process as we have had to leave behind some excellent players, including those who performed well at the PNC,” Betham said.
“But we cannot take everyone, and there is comfort is knowing that we have depth should we need to call on it.”
Samoa have been drawn in Pool B at the World Cup along with South Africa, Scotland, Japan and the USA.
World Cup squad:
Forwards: Ole Avei (Bordeaux Begles), Manu Leiataua (Aurillac), Motu Matu'u (Wellington Hurricanes), Viliamu Afatia (Agen), Jake Grey (Samoa Scopa), Logovi'i Mulipola (Leicester Tigers), Anthony Perenise (Bristol), Sakaria Taulafo (Stade FranÃ§ais), Fa'atiga Lemalu (Bourgoin), Filo Paulo (Benetton Treviso), Joe Tekori (Toulouse), Kane Thompson (Newcastle Falcons), Maurie Fa'asavalu (Oyonnax), Alafoti Faosiliva (Bath), Jack Lam (Bristol), Ofisa Treviranus (capt, London Irish), TJ Ioane (Sale Sharks), Sanele Vavae Tuilagi (Carcassonne).
Backs: Vavao Afemai (Samoa Vaiala), Kahn Fotuali'i (Northampton Saints), Patrick Fa'apale (Samoa Vaiala), Tusi Pisi (Suntory Sungoliath), Michael Stanley (unattached), Rey Lee-Lo (Cardiff Blues), Johnny Leota (Sale Sharks), Paul Perez (Coastal Sharks), George Pisi (Northampton Saints), Fa'atoina Autagavaia (Nevers), Ken Pisi (Northampton Saints), Alesana Tuilagi (Newcastle Falcons), Tim Nanai-Williams (Ricoh Black Rams) – AFP
Original source: Samoa names World Cup squad