Rhizoprionodon longurio (Compagno, 1984)

Gayford, Joel H, Whitehead, Darren A, Ketchum, James T & Field, Daniel J, 2023, The selective drivers of allometry in sharks (Chondrichthyes: Elasmobranchii), Zoological Journal of the Linnean Society 198 (1), pp. 257-277 : 265-267

Rhizoprionodon longurio (class-specific)

Regression of 11 morphological measurements against PL in all R. longurio individuals from Class Two recovered ten cases of isometric growth and one case of allometric growth ( Table 9 ). R 2 values varied from 0.19 (KC; Table 10 ) to 0.81 (FS; Table 9 ). The measurement DL showed significant negative allometry ( Fig. 8b ; Table 9 ). Regression of 11 morphological measurements against PL in all R. longurio individuals from Class Three recovered ten cases of isometric growth and one case of allometric growth ( Table 10 ). R 2 values varied from 0.02 (UL; Table 11) to 0.49 (LS; Table 10 ). The measurement UL showed significant negative allometry ( Fig. 8c ; Table 10 ).

PHYLOGENETIC GENERALIZED LEAST SQUARES (PGLS)

Phylogenetic generalized least squares regression against PL of mean trait values for both S. leaeini and R. longurio , together with the eight taxa studied by Irschick et al. (2017), yielded statistical evidence of interspecific allometry in LS ( Table 11). All other measurements did not differ significantly from isometry.

Figures

Figure 8. Linear regression plots for upper caudal lobe - UL in R. longurio following exclusion of neonates (A), dorsal fin length - DL in R. longurio Class Two (B) and upper caudal lobe - UL in R. longurio Class Three (C) against precaudal length - PL. All data are log10 transformed and the 95% confidence interval for the scaling coefficient is represented by the dark-grey area.