Marine scientist Emily Yeager has shed light on a curious behavior among suckerfish that hitch rides on larger marine animals like manta rays. Yeager’s research reveals that these suckerfish, also known as remoras, engage in a phenomenon dubbed “cloacal diving,” where they enter the cloaca of their hosts, potentially causing discomfort and harm.
In a recent interview, Yeager discussed her study published in the journal Ecology and Evolution, detailing how remoras dive headfirst into manta ray cloacas. Although this behavior has been observed with whale sharks before, this is the first documented evidence of such interactions with manta rays.
The study documented seven instances of cloacal diving over 15 years, but researchers suspect it occurs more frequently than reported. Yeager explained that the remoras may be reacting out of fear, as seen in a video where a startle response led a remora to dive into a manta ray’s cloaca.
Professor Brooke Flammang, who has studied remoras, suggested that the behavior could be related to the fish seeking food. She noted that such actions, termed coprophagy, are not uncommon in nature.
While the exact impact on manta rays remains unclear, Yeager expressed concerns about potential harm caused by the suction cup attachment of remoras. This behavior challenges traditional categorizations of the relationship between remoras and manta rays, highlighting the complex nature of symbiotic interactions in the marine ecosystem.
The study underscores the need to recognize the spectrum of relationships in nature, rather than fitting them into rigid categories. The findings offer new insights into the dynamics between marine species and the intricate balance of mutual benefit and potential harm in symbiotic relationships.
