Shark Suckers (HD) | JONATHAN BIRD'S BLUE WORLD

BlueWorldTV

19 Aug 201606:58

Summary

TLDRIn this episode of Jonathan Bird's Blue World, Jonathan explores the fascinating relationship between sharks and remoras. Remoras, known for their sucker-like dorsal fins, attach to sharks and other marine animals, providing a cleaning service by consuming parasites. Despite their usefulness, sharks often seem to be bothered by these hitchhikers. Jonathan conducts an experiment in Yap, observing how remoras struggle to reattach to sharks after being dislodged during feeding frenzies. The episode highlights the complex dynamics between these ocean creatures and the intriguing adaptations of remoras.

Takeaways

🐟 Remoras are known to attach themselves to various marine animals, including sharks, whales, and sea turtles.
🦈 Sharks, regardless of their size, often have remoras hitching a ride, with larger sharks attracting larger remoras.
🔍 Remoras are not parasites; they provide a service by eating parasites off their hosts, helping to keep them clean and healthy.
🍽️ These fish also benefit from the scraps of food that escape from the mouths of sharks while they are feeding.
🧲 Remoras have a unique adaptation: a modified dorsal fin that acts as a suction cup on the top of their heads, allowing them to attach securely to their hosts.
👀 The remora's sucker has a special design with smooth ribs in one direction and a rough, sandpaper-like texture in the other, facilitating a strong grip.
🎥 In an experiment, the host-shark's excitement during feeding caused many remoras to be knocked off, demonstrating the dynamic nature of their relationship.
🏊‍♂️ Remoras can be strategic and cautious when reattaching to a shark, indicating an awareness of the host's movements and reactions.
🐋 Sharks seem to dislike remoras, as they tend to move away when they sense a remora's presence, suggesting a form of interaction or even communication.
🌊 The underwater world is full of fascinating creatures like remoras, which have complex lives that we are still learning about.

Q & A

What is the relationship between remoras and sharks?
-Remoras, also known as suckerfish, are often found attached to sharks. They hitch a ride and feed on the scraps that escape the shark's jaws, as well as picking parasites off the shark, helping to keep it clean and healthy.
How do remoras attach to sharks?
-Remoras attach to sharks using a specialized sucker on the top of their heads, which is a modified dorsal fin that has evolved into a suction cup.
What is the purpose of the little flap of skin and ribs on the remora's suction cup?
-The little flap of skin allows the remora to form a suction cup, while the ribs, which are smooth in one direction and rough like sandpaper in the other, help it to grip onto the host's skin effectively.
Do remoras only attach to sharks?
-No, remoras are not limited to sharks. They can attach to a variety of marine animals including whale sharks, dolphins, whales, and sea turtles.
What happens to remoras when sharks become agitated or excited?
-When sharks become agitated, such as during feeding frenzies, many remoras can get knocked off. They then find themselves swimming without a host and must try to reattach to a shark.
How do sharks react when they feel a remora trying to attach?
-Sharks seem to dislike the presence of remoras. When they sense a remora trying to attach, they often turn away or move quickly to prevent the remora from getting a grip.
Why might remoras not find divers attractive as hosts?
-Remoras might not find divers attractive because divers may not have the parasites that remoras feed on, or perhaps the noise from scuba bubbles deters them.
What is the significance of the experiment conducted by Jonathan Bird with sharks and remoras?
-The experiment demonstrates the dynamic relationship between sharks and remoras, showing how remoras must adapt to reattach to their hosts after being dislodged, and how sharks sometimes actively avoid them.
How does the remora's ability to attach to various marine animals contribute to its survival?
-The remora's ability to attach to various marine animals provides it with a means of transportation, access to food, and protection from predators, which significantly enhances its chances of survival.
What is the conclusion drawn by Jonathan Bird about remoras after his observations?
-Jonathan Bird concludes that despite their seemingly simple appearance, remoras have a fascinating life and complex relationship with their hosts, and that there is still much to learn about them.

Outlines

00:00

🦈 Sharks and Their Hitchhikers: The Remoras

In this segment, Jonathan Bird introduces the audience to the fascinating world of remoras, fish that are commonly found attached to sharks. Despite their appearance, remoras are not parasites but play a crucial role in cleaning their hosts of parasites. They also feed on scraps left by sharks. The remora's unique suction cup, evolved from a modified dorsal fin, is highlighted as it allows them to attach to various marine animals, not just sharks. The segment also includes an experiment in Yap, where feeding sharks causes remoras to be dislodged, illustrating the dynamic relationship between these creatures.

05:04

🐟 The Art of Hitchhiking: Remoras and Their Hosts

This part of the script describes the challenges remoras face in reattaching to a host after being dislodged. The remoras' cautious approach to attaching without alerting the shark is detailed, along with the sharks' apparent dislike for the fish. The segment also humorously suggests reasons why remoras might avoid divers, such as the lack of parasites or the noise from scuba gear. The conclusion reflects on the intriguing life of remoras and the ongoing exploration of their behavior, leaving the audience with a sense of wonder about these oceanic creatures.

Mindmap

Keywords

💡Remoras

Remoras are a type of fish known for attaching themselves to larger marine animals, such as sharks, using a suction cup formed by a modified dorsal fin on their heads. In the video, Jonathan Bird discusses how remoras are often found attached to sharks, and they play a role in cleaning their hosts by eating parasites off them. The script provides a detailed description of the remora's suction cup and its function, illustrating the unique adaptation that allows these fish to hitch a ride on larger marine animals.

💡Suction Cup

A suction cup is a device that can adhere to surfaces by creating a partial vacuum between the cup and the surface. In the context of the video, the remora's head has evolved to form a suction cup, which is a modified dorsal fin with special ridges that allow it to stick tightly to its host. The script describes the remora's suction cup as having 'little ribs that are smooth in one direction and sandpapery rough in the other direction,' which helps it to attach securely to sharks and other marine animals.

💡Sharks

Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. The video script mentions various types of sharks, including Tiger sharks and gray reef sharks, which are known to have remoras as hitch-hikers. The script also describes an experiment where feeding sharks causes remoras to be knocked off, indicating the dynamic relationship between these two species.

💡Freeloader

A freeloader is someone who takes advantage of another's hospitality or resources without contributing. In the video, the term is used metaphorically to describe remoras, which are often found attached to sharks and other marine animals, seemingly getting a 'free ride.' The script explains that while they may appear to be parasites, they actually provide a service by cleaning their hosts, thus justifying their 'freeloading' status.

💡Parasites

Parasites are organisms that live on or in a host organism and derive nutrients at the host's expense. In the video, Jonathan Bird explains that remoras eat parasites off their shark hosts, which is a service that helps keep the sharks clean and healthy. The script provides an example of this symbiotic relationship where the remora benefits from the host's scraps and in return helps the host by removing parasites.

💡Dorsal Fin

The dorsal fin is a fin located on the back of a fish, providing stability and balance. In the case of remoras, the dorsal fin has evolved into a suction cup, as described in the script: 'This is actually their dorsal fin, which has evolved to become the suction cup.' This adaptation is a key feature that allows remoras to attach to their hosts and is central to their survival strategy.

💡Host

In biology, a host is an organism that harbors a parasite. In the video, the term is used to describe the larger marine animals, such as sharks, whales, and sea turtles, that remoras attach to. The script highlights the various types of hosts that remoras can be found on, emphasizing the wide range of marine life that can serve as a host for these hitch-hiking fish.

💡Symbiotic Relationship

A symbiotic relationship is a close, long-term interaction between two different species. In the video, the relationship between remoras and their hosts is described as symbiotic because the remoras benefit from the host by getting a ride and food, while the host benefits from the remoras by having its parasites removed. The script illustrates this relationship by explaining how remoras help keep their hosts clean and healthy.

💡Evolution

Evolution is the process by which species of organisms change over time through descent with modification. The script mentions the evolution of the remora's dorsal fin into a suction cup, which is a prime example of how species adapt to their environment. This adaptation has allowed remoras to develop a unique way of living, attaching to larger marine animals for transportation and feeding opportunities.

💡Experiment

An experiment is a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact. In the video, Jonathan Bird conducts an experiment to observe the behavior of remoras and sharks. The script describes how he feeds sharks to get them excited and observes the resulting interactions between the sharks and remoras, providing insights into their natural behaviors and the challenges remoras face in reattaching to their hosts.

💡Adaptation

Adaptation in biology refers to the process by which an organism becomes better suited to its environment. The script discusses the remora's suction cup as an adaptation, which is a result of millions of years of evolution. This adaptation allows the remora to attach to various marine animals, demonstrating how species can develop unique features to survive and thrive in their ecological niches.

Highlights

Remoras are hitch-hikers on sharks, often seen hanging on for a free ride.

Sharks of all sizes, from Tiger sharks to whale sharks, can have remoras attached.

Remoras are not parasites; they help keep their host clean by eating real parasites off them.

These fish also feed on scraps that escape from the shark's jaws.

Remoras use a suction cup on their head, evolved from a modified dorsal fin, to attach to their host.

The suction cup has little ribs that are smooth in one direction and rough like sandpaper in the other, aiding attachment.

Remoras can hold their own weight even when out of water, demonstrating the strength of their suction.

Experiments on the island of Yap show how remoras react to sharks being fed and excited.

Sharks often knock off remoras when they are excited and competing for food.

Remoras need to be strategic in reattaching to a shark, avoiding detection.

Sharks seem to dislike remoras, as they tend to swim away when they sense them.

Getting a free ride on a shark is more challenging than it appears for remoras.

Divers are not attractive to remoras, possibly due to the lack of parasites or the noise from scuba bubbles.

Despite being seen many times, the fascinating life of remoras is still not fully understood.

The ocean's creatures, like remoras, continue to amaze with their unique adaptations and behaviors.