DOI: 10.5061/dryad.zkh1893n0
title: Diverse musculature layers in three species of octopus support precise motor control yet lack smooth muscle.

description: 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
 significantly lower muscle fiber density in the internal longitudinal
 layer of O. bimaculoides and A. aculeatus, and smaller internal
 mitochondria cores (with larger muscle area) compared to the external
 longitudinal layer in O. bocki. This suggests additional functional muscle
 layers that would give octopuses even greater precision in motor control
 of their arms. The data provided as part of the manuscript will be
 arranged as a series of images that support each of the subpanels of the
 figures. 
description: # 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 manuscript. File list follows... Figure 2 Folder
 Figure_2A_Left_Full_resolution.tif = Raw data image
 Figure_2A_Right_Full_resolution.tif = Raw data image
 Figure_2B_Full_resolution.tif = Raw data image
 Figure_2C_Full_resolution.tif = Raw data image Figure 3 Folder
 Figure_3A_Left_Full_resolution.tif = Raw data image
 Figure_3A_Right_Full_resolution.tif = Raw data image
 Figure_3B_Left_Full_resolution.tif = Raw data image
 Figure_3B_Right_Full_resolution.tif = Raw data image
 Figure_3C_Left_Full_resolution.tif = Raw data image
 Figure_3C_Right_Full_resolution.tif = Raw data image
 Figure_3D_Left_Full_resolution.tif = Raw data image
 Figure_3D_Right_Full_resolution.tif = Raw data image Figure 4 Folder
 Figure_4A_Left_Full_resolution.tif = Raw data image
 Figure_4A_Right_Full_resolution.tif = Raw data image
 Figure_4B_Left_Full_resolution.tif = Raw data image
 Figure_4B_Right_Full_resolution.tif = Raw data image
 Figure_4C_Left_Full_resolution.tif = Raw data image
 Figure_4C_Right_Full_resolution.tif = Raw data image
 Figure_4D_Left_Full_resolution.tif = Raw data image
 Figure_4D_Right_Full_resolution.tif = Raw data image Figure 5 Folder
 Figure_5_Full_resolution.tif  = Raw data image Figure 6 Folder
 Figure_6A_Full_resolution.tif  = Raw data image
 Figure_6B_Full_resolution.tif  = Raw data image
 Figure_6C_RawData_Internal_v_External_Densities.xlsx  = Raw data, details
 contained within sheet Figure_6D_Full_resolution.tif  = Raw data image
 Figure_6E_RawData_Internal_v_External_Areas.xlsx  = Raw data, details
 contained within sheet Supplemental Folder
 Supplemental_Figure_1A_Full_resolution.tif  = Raw data image
 Supplemental_Figure_1B_Full_resolution.tif  = Raw data image
 Supplemental_Figure_2_Full_resolution.tif  = Raw data image
 Supplemental_Figure_3_Full_resolution.tif  = Raw data image Considerably
 more imaging data was collected as we obtained tiled z-stacks from many
 sections and many arms from multiple species of octopus. Thus we are
 unable to upload all of the raw data.  It is over 5 TB and so not able to
 stored on a data repository. If required, all the raw data is available
 from the lead contact upon request, providing hard drives and postage
 costs are covered. ## Code/software Images are best opened and viewed
 using
 FiJi. [https://imagej.net/software/fiji/downloads](https://imagej.net/software/fiji/downloads) There was no unique code made for the analysis of images.  ## Access information There are no other publicly accessible locations of the data used for this manuscript. Scanning electron data was derived from Robyn Crook.  [https://biology.sfsu.edu/faculty/crook](https://biology.sfsu.edu/faculty/crook) [rcrook@sfsu.edu](mailto:rcrook@sfsu.edu)