Australia's swimming star Kaylee McKeown has issued a sobering warning to her fellow world pacesetters ahead of the Tokyo Olympics.
"Once you get to that number one spot, it's even harder to stay there," McKeown said.
Australia on Thursday night named a 35-strong swim team for next month's Tokyo Olympics.
In nine events, an Australian is currently ranked top in the world this year.
McKeown holds top billing in three of them: she broke the 100m backstroke world record on Sunday night and is also the world leader in the 200m backstroke and 400m individual medley.
Emma McKeon, who could contest eight events at the Games, is the world's pacesetter in the 100m and 200m freestyles, with Ariarne Titmus holding that status in the 400m and 800m freestyles.
Elijiah Winnington (400m freestyle) and Zac Stubblety-Cook (200m breaststroke) also hold the year's best times in their events.
The Dolphins team features two swimmers who will compete at their fourth Olympics, freestyler Cate Campbell and backstroker Emily Seebohm.
Campbell and Seebohm join Leisel Jones as the only Australian swimmers to make four Olympic teams.
Three swimmers - Mitch Larkin, Bronte Campbell and Cam McEvoy - will race at their third Olympics.
Bronte Campbell and McEvoy made the team as relay squad members while Larkin is a medal contender in the 200m individual medley while also securing a 100m backstroke swim.
The 19-year-old McKeown is among 21 Olympic debutants on a team featuring 18 men and 17 women.
Only one Australian swimmer, 100m freestyler Kyle Chalmers, will defend an Oympic title.
Mack Horton, the reigning Olympic 400m freestyle champion, missed selection for individual swims in that event and the 200m freestyle, but made the team as a relay squad member.
And selectors also threw an Olympic lifeline to breaststroker Matt Wilson.
Wilson was picked as a relay squad member - he finished second behind Stubblety-Cook in the 200m breaststroke, some 0.24 seconds outside the qualifying time specified by Swimming Australia.
In 2016, Wilson won the breaststroke race at trials but was 0.26s shy of the qualifying mark and missed the team for the Rio Games.
Wilson was added to the Tokyo team as a discretionary pick, with selectors saying a family bereavement had disrupted his trial performance and preparation.
"This is a strong team," Swimming Australia's head coach Rohan Taylor said.
"I'm particularly pleased with the strength of our relays, it shows the fantastic depth in this squad.
"We have a big five weeks ahead of us.
"Now it's about preparing our athletes for what they'll experience and get them ready to perform on the biggest stage in the world in Tokyo."
