A power amplification dyad in seahorses.

Area of Science:

• Biomechanics
• Evolutionary Biology
• Hydrodynamics

Background:

• Organisms evolve elastic elements to enhance explosive movements beyond muscle power limits.
• Seahorses possess a latch-mediated spring-actuated (LaMSA) mechanism, but its role in feeding is not fully understood.
• Feeding in seahorses involves rapid head swings and suction to capture prey.

Purpose of the Study:

• To investigate how the LaMSA system powers seahorse feeding.
• To quantify the power requirements and fluid dynamics of suction feeding in seahorses and other fish.
• To identify the specific elastic elements responsible for actuating seahorse feeding.

Main Methods:

• Flow visualization and hydrodynamic modeling were used to estimate power for suction feeding in 13 fish species.
• Material testing was performed on seahorse sternohyoideus tendons.
• Comparative analysis of suction feeding power across species.

Main Results:

• Seahorse suction feeding power is ~3x higher than maximum vertebrate muscle capacity.
• Seahorse suction flows are ~8x faster than those of similar-sized fishes.
• Sternohyoideus tendons release ~72% of the power needed for water acceleration.

Conclusions:

• The seahorse LaMSA system utilizes two elastic elements: sternohyoideus and epaxial tendons.
• These tendons coordinate head acceleration and fluid intake for efficient prey capture.
• This study expands the understanding of LaMSA system function, capacity, and design in vertebrates.