Fish communication

Fish Communication

Fish aren’t traditionally perceived as having personalities, but they’re anything but the dumb automatons that our ancestors would have us believe.

Underwater organisms don’t have the facial musculature that we as primates have evolved. Quite simply they haven’t needed it, therefore they haven’t acquired it through natural selection.  However they have  been evolving and surviving on this planet for over 500 million years.

And they do communicate to each other.

How do fish sense each other?

In a Darwinian world where survival is paramount, the lateral line has become their first defense and sensory organ. This first level of communicating allows the individual to feel what’s around it. The layer of sensory cells that run along the flanks of most fish, detect the pressure changes in the surrounding environment. This system has evolved to the point where fish react with an almost simultaneous motion to an external stimulus.

silver fish

school-silver-fish-evade-predators-footage-007763027_main_xl.mp4

How do fish school in such dense numbers without colliding?

Fish have a sensory barrier around them, a kind of bubble that they can perceive. This bubble is squashed as objects or animals move around the individuals perception. They can sense their immediate surroundings in this fashion.

Some fish such as the freshwater knife-fish even generate electric fields. These fields are influenced by their surroundings, especially other animals, and the knife-fish react to that reflection of their own electric field and use it to locate prey.

Sharks have an extremely sensitive network of electroreceptors that can detect the smallest electric fields from other animals.

Vision is also important in the depths of the ocean especially in the upper Euphotic zone (where photosynthesis can occur). Most of the longer, lower energy wavelengths are lost quickly, absorbed by the water column. Red light disappears first, then orange, then yellow… leaving only blue as you descend to the furthest depths of the Photic zone (The depth that light can penetrate through water).

How do fish display their intentions?

Contrast over actual color makes a big difference at depth and aquatic animals can use that to their advantage to display their intentions. Humbolt squid for example can change their entire body from red to white and back like you can flick a light switch. They do this at depths far beyond red light can be seen (200m-700m) so appear in this twilight world as if they are going from black to white like individual morse code signals. What they are saying to each other is beyond our understanding.

Closer to the surface we have fish species that utilize many more frequencies of the electromagnetic spectrum including the ultraviolet wavelengths.

underwater fish
The stripes behind the eyes of this saddleback Toby reflect ultraviolet wavelengths.

On a more day to day scenario, most SCUBA Divers and snorkelers who pay attention will have noticed that some species of reef fish can have drastically different colourations. Take the Big eye crescent tail as an example.

school of silver and red fish
The red phase can bleach out to a silver within seconds

When it’s calm an individual will be a deep red, when stressed it can bleach to a silver. Similarly when fish such as the Big-nose Unicornfish visit cleaning stations they can display complex patterning only for it to fade to black once the fish swims away.

When fish think about sex

During spawning aggregations many fish species undergo drastic color changes that signal their readiness to participate. The bumphead parrotfish are pretty obvious during their aggregation as their heads bleach white from the usual green.

Bumphead Parrotfish spawning coloration
Bumphead Parrotfish spawning coloration

In the Caribbean, Nassau groupers migrate in groups to their annual spawning grounds and are often led by an individual who sports a drastically different body patterning. Once at the spawning site they all adopt an even more extreme color change. For further reading see this article.

Bohar Snappers have a variety of different colorations during their spawning aggregations, sometimes two small white spots appear on their dorsal area, others adopt a bleached blue hue rather than their usual russet red. Others adopt a mixture of the two with a red belly, a white stripe down their flanks and a bluish dorsal area. As I pour over the many spawning rushes I’ve filmed of this species I cannot see any distinguishable pattern in whether a female adopts a certain body color prior to her egg releasing rush.  A pattern may emerge after further observations though.

See this clip of a small group interacting in preparation for spawning. The female with the broken dorsal fin is being nudged by a number of males. Maybe this nudging is meant to initiate her egg releasing rush. Maybe it’s the males trying to ascertain if she is ready or not….?

Bohar snapper spawning aggregation
Bohar snapper spawning aggregation

For a really in depth look at this behavior and other similar color changes seen during spawning, Tony Wu has written an excellent series of articles that are well worth a read.

Additional articles and films of Palau’s spawning aggregations can be found here.

Communication between species

It has been shown that fish communicate between species. In the case of the Grouper and Moray Eel, the Grouper will shake it’s head next to the Eel to signal an intention to start hunting. The strategy has been shown to be more successful at catching prey. 

fish communication
Grouper, Moray cooperative hunting. Palau
Underwater acoustics in fish

Underwater acoustics is not just the tool of marine mammals, many fish  are also extremely vocal. Have you ever swum over a reef and heard all the clicking noises? This is a medley of fish and crustaceans each with their own message. Usually the message is “this is my territory, keep out”. Sound is an extremely useful form of communication in the aquatic environment as sound travels much further than light. A fish can remain hidden whilst  letting an intruder know that it’s encroaching. Groupers often growl or rumble from within their hiding place. The behavior across a multitude of species was documented here and demonstrates the rich complexity in coral reefs.

So in conclusion, whilst fish and other aquatic organisms like cephalopods might not be able to convey their intentions through facial cues like we can, they are extremely in tune with and aware of their environment. They are able to send messages that even other species can understand. The fact that we might not be able to understand them is perhaps our failure rather than theirs.

Have you had any interesting interactions with aquatic wildlife? I’ve not begun to get started with the marine mammals here, whole different kettle…..so there’s still a load more to talk about. Feel free to leave a comment in the section below. Do you know the difference between a head nod and a shake in Moray Eels, can you predict when a Stingray is about to lift up and depart from it’s resting place? So many more topics and examples for the future.

For more info on filming underwater  and learning about your subjects this article may well be helpful.

Until next time, Cheers!

Richard

 

References

http://jeb.biologists.org/content/216/13/2515

The evolution and development of vertebrate lateral line electroreceptors

Clare V. H. BakerMelinda S. ModrellJ. Andrew Gillis

2018 Palau Show Reel released

Film Palau

The Republic of Palau continues to provide great opportunities for Media Production. I would like to share some of the highlights from the past year and our hopes for the future.

New media techniques and projects in Palau

Over the last 12 months we have continued to diversify our filming techniques. Aerial filming with Drones and Aircraft mounted action cams have provided great footage for our clients.

Exciting 6K B-roll from Time-lapse techniques have also added to production value.

We have embraced 360 VR and continue to develop this new and exciting form of media. Mosaic panoramas provide a new and artistic form in addition to producing very high resolution images for printing.

Underwater filming in Palau is still incredible. New behaviors and environments were documented in greater detail this past year. Our cameras can output 4K Raw footage. This means we get the very best colors possible in UHD.

Wildlife and conservation topics are still very close to our hearts. A large project on migratory shorebirds was completed in the Autumn. This milestone project raised local awareness for the need to protect certain coastal environments in Palau.

Plastic Pollution is an incredibly damaging aspect of our world in this century. This film was our first venture into raising awareness of this issue

I would like to take this opportunity to thank you all for your continued support into 2018.

Together we can make Lightning Strike Productions grow further and provide more innovative and educational media for Palau and Micronesia.

Here’s to a productive and imaginative 2018!

For more information find us here

Thank you and Enjoy!

 

 

Palau Stock Footage and High Speed Internet!

Stock footage from Palau

Stock Footage is often vital for a production to stay within budget and after 10 years of diving and filming in Palau we have accumulated a huge library of HD and UHD stock footage for just that purpose.

Previously in Palau, uploading at 3kb/s was about all we could hope for on a wobbly internet and this made sending any large files almost impossible. Palau now enjoys high speed internet from an undersea fibre optic cable and with this we have been uploading stock footage to our agents with unprecedented speed.

Palau Stock Footage subjects

Manta Rays

Manta Ray palau stock footage

 

 

 

Sharks

Shark palau stock footage

 

 

 

Turtles

turtle palau stock footage

 

 

 

Jellyfish Lake

jellyfish lake palau stock footage

 

 

 

Aerials of Palau

aerial palau stock footage

 

 

 

Spawning Aggregations

spawning aggregations palau stock footage

 

 

 

 

Check out these categories and others. With over 1000 clips now available at a variety of stock agencies you can be sure that you will find something to suit your needs.

Royalty Free or Rights Managed portfolios can be found here:

 

palau stock footage

 

 

 

palau stock footage

 

 

palau stock footage

 

 

palau stock footage

 

 

If you don’t see what you need give us a shout here and we can discuss options for acquiring footage for you.

Check back often as our portfolios will now be rapidly expanding. See here for our latest show reel.

We are filming on an almost daily basis so will always have new content coming.

Cheers

 

Richard

Spawning aggregation dives in Palau

As natural events go, very little compares to fish spawning aggregations and it’s the time of year again to be diving Peleliu. Both the Sailfin Snapper (Symphorichthys spilurus) and Red Snapper (Lutjanus bohar) are starting to aggregate along the east reefs of Yellow Wall and Peleliu Express to the corner.

For those intrepid divers, early morning dives just before the full moon will find them spawning in their thousands. Also making an appearance are the predators such as Bull Sharks and Oceanic Black Tips.

How to find the aggregations

I joined Dari Divers for this trip as they know exactly where and when to jump in, even once on the reef they can interpret the fishes behavior and know how to approach them. Check out the edited short film from this year:

 

Check out last years showreel with footage from the Red Snapper spawning dives here.

Watch this space for updates as we return to document this impressive natural event.

 

Cheers

 

Richard

 

Winged Ambassadors of Palau

Protecting Migratory Shorebirds in Palau

Many thousands of migratory shorebirds stop-over in Palau to rest and feed, one of them is the Whimbrel. In Palau it is called the Okak. The Okak has a larger much rarer cousin, the Far Eastern Curlew, so rare only around 5 birds get spotted here each year. This is the largest species of Curlew and is also know in Palauan tradition as the money bird. The story goes that it visits these shores and leaves gifts behind. It swallowed traditional money and flew to parts of Palau, where if it was left to settle and not disturbed it would eventually defecate out the money and the residents would become rich.

You can find the symbols all over traditional meeting housings and Government buildings.

The Delerok or Far Eastern Curlew or Money Bird in Palau
The money bird as depicted on the Capital Building, Melekeok.
Camera gear for filming birds

Today I utilized my new canon 70-300 lens coupled to a 2x teleconverter and managed to get some nice stable footage of this Whimbrel even at full zoom. The Image stabilization of the canon lens is amazing!

migratory shorebirds palau
The Whimbrel also known as the Okak
Wildlife conservation in Palau

The NGO spearheading this initiative to raise awareness about the plight of these birds is the Palau Conservation Society but this is far from the only work they do. See their website for more information and how to help them achieve their goals.

Palau Conservation Society commissioned me to make a film highlighting the status of Palau’s migratory shorebirds and for about 9 months we collaborated with local bird and conservation experts to create this film which is being shown across Palau: