Table 1.

Correlations of vortex circulation, pressure coefficients and pitching moment coefficients for various boxfishes

BoxfishComparisonCountZ-valueP-valuer95% lower C.I.95% upper C.I.
SB C vs P 74.35<0.00010.9740.8320.996
SB C vs M 74.61<0.00010.9800.8680.997
SB P vs M 73.840.00010.9580.7350.994
SC C vs P 73.720.00020.9530.7060.993
SC C vs M 74.84<0.00010.9840.8940.998
SC P vs M 75.19<0.00010.9890.9240.998
BT C vs P 74.13<0.00010.9680.7960.995
BT C vs M 65.35<0.00010.9960.9611.000
BT P vs M 63.660.00030.9710.7540.997
  • SB, spotted boxfish; SC, scrawled cowfish; BT, buffalo trunkfish.

    C, vortex circulation; P, pressure coefficient; M, pitching moment coefficient; r, correlation coefficient.

    Circulation of vortices found above (positive pitch angles) and below (negative pitch angles) the ventral keels at the posterior edge of the carapace were used in the correlations. Pressure coefficients at ports just above (positive pitch angles) or just below (negative pitch angles) the ventral keels, at the posterior edge of the carapace in locations where vortex circulation was measured, were used in the correlations. Data at pitch angles of 30, 20, 10, 0, –10, –20 and –30° were considered in correlations for the spotted boxfish and scrawled cowfish. These angles also were considered in the buffalo trunkfish for correlations between vortex circulation and pressure coefficient, but –30° was omitted from correlations involving pitching moment coefficients because of a lack of data.