Data from: Integration and modularity of teleostean pectoral fin shape and its role in the diversification of acanthomorph fishes

Phenotypic integration and modularity describe the strength and pattern of
interdependencies between traits. Integration and modularity have been
proposed to influence the trajectory of evolution, either acting as
constraints or facilitators. Here, we examine trends in the integration
and modularity of pectoral fin morphology in teleost fishes using
geometric morphometrics. We compare the fin shapes of the highly diverse
radiation of acanthomorph fishes to lower teleosts. Integration and
modularity are measured using two-block partial least squares analysis and
the covariance ratio coefficient between the radial bones and
lepidotrichia of the pectoral fins. We show that the fins of acanthomorph
fishes are more tightly integrated but also more morphologically diverse
and faster evolving compared to non-acanthomorph fishes. The main pattern
of shape covariation in non-acanthomorphs is concordant with the main
trajectory of evolution between non-acanthomorphs and acanthomorphs. Our
findings support a facilitating role for integration during the
acanthomorph diversification. Potential functional consequences and
developmental mechanisms of fin integration are discussed.