Suckerfish, commonly referred to as remoras, have gained attention for a peculiar behavior observed in manta rays. These little fish typically attach themselves to larger marine animals like sharks and manta rays, benefiting from the ride while helping to clean their hosts of parasites. However, recent research reveals a surprising twist to this relationship.
Suckerfish Dive Boldly into Manta Rays’ Rear-Ends
A new study led by Emily Yeager, a marine researcher at the University of Miami, highlights a behavior termed “cloacal diving.” This phenomenon involves remoras diving directly into the cloaca of manta rays, creating potential discomfort for their hosts. Yeager describes this action as possibly uncomfortable for manta rays, given the sensitive nature of the cloaca, which serves multiple biological functions.
The Study and Observations
The research, published in the journal *Ecology and Evolution*, offers documented evidence of this interaction, noting seven instances across various ocean locations over a span of 15 years. Yeager suspects that these occurrences are underreported, as many dives might go unnoticed, with only the tail of the remora visible.
- Transitioning into the cloaca appears to be a fear response for the remora.
- In one observed incident off the coast of Florida, a diver startled a remora, prompting it to dive into the manta ray’s cloaca.
- The manta ray reacted with a noticeable shudder, indicating discomfort.
Possible Motivations for Cloacal Diving
Brooke Flammang, a professor at the New Jersey Institute of Technology, suggests that this behavior may also be motivated by the desire to consume residue, a phenomenon known as coprophagy. Flammang highlights that remoras can be territorial and may rush to secure food, leading to this unusual diving behavior.
Implications for Manta Rays
The potential harm of cloacal diving on manta rays remains a concern. Yeager notes that the suction cups of remoras can cause skin damage to their hosts. If this behavior leads to injury in the sensitive cloaca region, it could severely impact the manta ray’s reproductive and waste excretion capabilities.
Rethinking Relationships in Nature
This research challenges the traditional understanding of the remora-manta ray relationship, typically categorized as either symbiotic or commensal. Yeager emphasizes that nature’s relationships are complex and exist on a spectrum rather than fitting into neat classifications.
As researchers continue to study these interactions, the behaviors of suckerfish and their impact on manta rays offer fresh insights into the complexities of marine life.
