Data from: Extremely fast feeding strikes are powered by elastic recoil in a seahorse relative, the snipefish, Macroramphosus scolopax
Longo, Sarah J., Duke University
Goodearly, Tyler, Trinity College
Wainwright, Peter C., University of California, Davis
Published Jun 13, 2018 on Dryad.
Cite this dataset
Longo, Sarah J.; Goodearly, Tyler; Wainwright, Peter C. (2018). Data from: Extremely fast feeding strikes are powered by elastic recoil in a seahorse relative, the snipefish, Macroramphosus scolopax [Dataset]. Dryad. https://doi.org/10.5061/dryad.hb6b0
Among over 30,000 species of ray-finned fishes, seahorses and pipefishes have a unique feeding mechanism whereby the elastic recoil of tendons allows them to rotate their long snouts extremely rapidly in order to capture small elusive prey. To understand the evolutionary origins of this feeding mechanism, its phylogenetic distribution among closely related lineages must be assessed. We present evidence for elastic recoil powered feeding in the snipefish (Macroramphosus scolopax) from kinematics, dynamics, and morphology. High-speed videos of strikes show they achieve extremely fast head and hyoid rotational velocities, resulting in rapid prey capture in as short at 2 ms. The maximum instantaneous muscle-mass-specific power requirement for head rotation in snipefish was above the known vertebrate maximum, which is evidence that strikes are not the result of direct muscle power. Finally, we show that the over-center conformation of the four-bar linkage mechanism coupling head elevation to hyoid rotation in snipefish can function as a torque reversal latch, preventing the head from rotating and providing the opportunity for elastic energy storage. The presence of elastic recoil feeding in snipefish means that this high-performance mechanism is not restricted to the Syngnathidae (seahorses and pipefish) and may have evolved in parallel.
R scripts for kinematics and power calculations
This zip file includes scripts used to calculating kinematic variables and calculating muscle mass specific power requirements from high speed videos and morphological measurements
High speed video example
Example high speed video of a snipefish feeding strike. Strike was filmed at 2000 fps and is played back at 30 fps.
Relative linkage lengths and other variables calculated from high speed video for four-bar linkage mechanism in snipefish. Each file represents one feeding sequence, which each row representing variables calculated for a single frame in the video. README file explains the column headers.
Output from power requirement calculations
This zip file contains the output for each feeding sequence from calculations of muscle mass specific power requirements and related variables (rotational velocities, accelerations, energy, etc). KINE files are each from a different feeding sequence, where rows are variables calculated at that frame. snipefishOutputSummary_forFig2 contains the aggregated information for peak instantaneous muscle mass specific power requirement. README explains all column headings.
This zipped files includes a video highlighting some of the muscles associated with the pectoral girdle, hyoid, and urohyal. This video was created from a micro-CT scan and shows sections through a volume rendering of a snipefish with the suspensorium adducted (as in Figure 3A, B, and D). Two annotated still are included to help identify structures of interest and provide orientation.