Data from: Evolution of the intermuscular bones in the Cyprinidae (Pisces) from a phylogenetic perspective

Intermuscular bones (IBs) are widely present in morphologically
generalized teleost fishes, and are commonly found in the Cyprinidae. IBs
are small, hard spicules of bone that form by ossification in the myosepta
between neighboring myomeres. Why fish have IBs, and whether there is any
evolutionary pattern to their occurrence, have been poorly understood.
However, the presence of IBs do substantially affect the meat quality and
commercial values of many cyprinid fishes in aquaculture. In this study,
we sampled 592 individuals of cyprinid fishes to systematically
investigate the evolution of IBs from a phylogenetic point of view. We
found that the total number of IBs in the Cyprinidae ranged from 73 to
169, and we clarified that only two categories of IBs (epineural and
epipleural) were present in all examined cyprinids. Most of the IBs were
distributed in the posterior region of the fish, which might be an optimal
target for selecting fewer IBs strains in aquaculture. There was a
positive correlation between IBs and the number of vertebrae, thus making
it possible to predict the approximate number of IBs by counting the
number of vertebrae. Although the IBs displayed some correlation with
phylogenetic relationships in some lineages and to ecological factors such
as diet (especially carnivore), in an overall view the variations of IBs
in cyprinids were extremely diverse. The number and patterns of IBs in
these fishes may reflect their phylogenetic history, but has been shaped
by multiple environment factors. In this study, we also confirmed that
X-ray photography remains an optimal and reliable method for the study of
IBs.