Mummichogs - Gymnasts of the Tidal Pool

Few environments are as harsh as the intertidal zone. Organisms must adapt to this variable environment or face death. Many develop amphibious traits, allowing for survival both on land and in water. Additionally, some organisms have developed motor skills as a means to self-relocate into the water. The behavior and actions of the mummichog demonstrate these properties and claim the gold medal for gymnastics in the tidal pool.

Mummichogs performed their gymnastics floor routine under laboratory conditions at the Shoals Marine Laboratory in the Gulf of Maine. Monitored by high speed and normal video cameras, each routine was broadcast across the lab for judges and audience members to see.

Every gymnast must know and plan their path. Mummichogs, though able to breathe air, prefer their native environment in the water. Their routine ends upon reentry into the tidal pool. Impressively, despite being unable to focus their sight on land, mummichogs rely on the ability to visualize reflected light. Mummichogs interpret this reflected light as being the water, orient themselves in the direction of the reflected light, and perform a gymnastic routine to return to the water. However, mummichogs were unable to discern the difference between light reflected off of the water and light reflected off the aluminum foil. Furthermore, mummichogs were also challenged and mostly failed, at locating the water in dark conditions.

The mummichogs’ routine consists of calculated and acrobatic moves, designed to maximize the effectiveness of the motion in propelling themselves forward. Mummichogs begin by orienting the tail to the direction of travel. They then contort themselves, bringing their heads to their tails in a tuck, and then pushing off the ground to leap. Mummichogs then visually  reorient themselves and continue towards the reflected light. While seemingly boring and lacking variance, the mummichogs’ routine happens to be a concerted, carefully calculated leap of faith. One misstep can entrap the mummichog in a coastal crevice and lead to certain death.

As if the moves weren’t enough, mummichogs engage in “prone posturing.” In this position, the mummichog seeks admiration from the audience and judges. Prone posturing also signals the highly expert level of tide pool gymnastics; it is a trait evolved after a species had significant terrestrial activity on land. The prone posture allows the mummichog to re-evaluate its bearing and confirm the direction for its next routine. As a true athlete does, the mummichog takes in the admiration for only a moment, and channels that energy into its next routine. The mummichog strives for perfection; it will only be satisfied when safely back in the water.

The mummichogs complete their routines! The crowd goes wild; all receive perfect tens. Not even humans could compete with the mummichog routine. The next time you are along the coast, you may have a chance to experience the live show and contribute your cheers.