Vertebral morphology in the tail-whipping common thresher shark, Alopias vulpinus

Thresher sharks (Alopias spp.) are characterized by an elongated, scythe-like caudal fin that is used in tail-whipping, a behavior where the tail is thrown overhead to stun prey. Tail-whipping is performed via extreme dorsoventral bending of the vertebral column and is dramatically different from lateral oscillatory motion used for swimming. Previous work has examined thresher shark vertebral morphology and mechanical properties but in the context of swimming loads. Our goal was to assess centra morphometrics and microarchitecture for variations that may support extreme dorsoventral bending. We examined anterior and posterior body vertebrae from an embryo, 5 juvenile, and 4 adult thresher sharks using micro-computed tomography. We used principal component and landmark analyses to examine variables influencing vertebral morphology and mineral arrangement, respectively. We found that morphology and microstructure significantly varied across body regions and ontogeny. We hypothesize that a..., , , # Vertebral morphology in the tail-whipping common thresher shark, Alopias vulpinus

Using micro-CT scan data, we measured vertebral morphology and quantified microstructure in anterior and posterior vertebrae from 10 thresher sharks.

## Description of the data and file structure

Describe relationships between data files, missing data codes, other abbreviations used. Be as descriptive as possible.

* ID = ID for shark
* FL = fork length (cm)
* ONT= ontogenetic stage (Juvenile or Adult)
* SEX= shark sex
* VERT= vertebra ID
* A V P = body region (anterior or posterior)
* BR.OS = body region and ontogenetic stage category (Anterior.Juvenile, Anterior.Adult, Posterior.Juvenile, or Posterior.Adult)
* W = centrum width (mm)
* W.S = centrum width standardized
* H = centrum height (mm)
* H.S = centrum height standardized
* L= centrum length (mm)
* L.S = centrum length standardized
* LC = lamellae count average
* NC = node count average
* NA1 = dorsal arch an...