xmin := 0
xmax := 2*Pi
ymin := 0
ymax := Pi
ro[t_, p_] := 
      2.5 - Sqrt[(1 + Sin[2  p]^2)*(1 + Sin[3  t]^2)]
xxx[t_, p_] := ro[t, p]*Sin[p]*Cos[t]
yyy[t_, p_] := ro[t, p]*Sin[p]*Sin[t]
zzz[t_, p_] := ro[t, p]*Cos[p]
ParametricPlot3D[{yyy[t, p], -xxx[t, p], zzz[t, p]}, {t, xmin, 
        xmax}, {p, ymin, ymax}, PlotPoints -> {31, 31}]