Diverse musculature layers in three species of octopus support precise motor control yet lack smooth muscle.

Octopus intrinsic arm musculature is often referred to as entirely obliquely striated muscle. However, only three muscle layers have been systematically shown as striated muscle. Because molluscan muscle control can vary greatly (i.e. smooth vs striated types), a systematic examination of each arm muscle layer is necessary to understand its neuromuscular control. Here, we use 2-photon microscopy to determine if striations are present in the eight layers and trabeculae of intrinsic arm muscle in Octopus bimaculoides (California two-spot octopus) and Abdopus aculeatus (“prickly” octopus). We also use scanning electron microscopy (SEM) to examine the arm of Octopus bocki (Bock’s pygmy octopus). We confirm for the first time that each intrinsic arm muscle layer from multiple octopus species is obliquely striated. Furthermore, we find that the two layers of longitudinal muscle-- divided by the median oblique layer--exhibit different morphology. This occurs in all three species examined, with..., , # Diverse musculature layers in three species of octopus support precise motor control yet lack smooth muscle.

Dataset DOI: [10.5061/dryad.zkh1893n0](10.5061/dryad.zkh1893n0)

## Description of the data and file structure

Data is provided as a tar file (Octopus_Muscle_-_Dryad_Figure_Data.tar).  The research study generated images to investigate morphological differences between muscle types within the arm of three octopus species.  Data was collected as described in the manuscript. Briefly, cut sections of octopus arm tissue were stained with phalloidin and imaged using two-photon microscopy.  We also used scanning electron microscopy data from cut sections of octopus arms. 

### Files and variables

Each folder within the tar file contains the full resolution raw images used to make each of the sub panels for a given figure. The figures are numbered and subpanels are identified with letters and so are the images.  Details regarding each image in each subpanel are found in the manusc...,