Fig. 5. The fins of Loligo opalescens are triangular; surface area (SA) of both fins=2(0.5 x fin width x fin length at the base). The surface area of both fins provides lift that increases exponentially with the dorsal mantle length ML of the developing squid. y=2.361x–2.214; r²=0.957, P<0.0001, N=136. The slope of the linear regression line is 2.361, demonstrating positive allometry, i.e. slope is significantly different than 2.