In Medieval bestiaries, the Echeneis was said to be a six-inch-long fish that dwelled in the Indian Ocean. It had a sucker atop its head which it could attach to a passing ship, thus rendering it immobile. The Echeneis could keep a boat rooted in the water even during a storm. The force of the Echeneis' power was greater than the strength of fifty oarsmen. To get a ship moving again the Echeneis had to be removed by force-- pried off by a sailor or scraped off against a rock, for example. The Echeneis was probably based off of a real animal, the remora. The remora clings to larger creatures like sharks for transport. In fact, the Echeneis was sometimes referred to as the remora, which provides even greater evidence for this hypothesis.