Sharks are AMAZING - Breeding tidbit

[nabokovfan87]

I was reading through this due to trying to help answer a question in another thread and I found something interesting!  It makes perfect sense and it involves sharks, so I'm happy I learned something new today!

https://acoustical-consultants.com/built-environment/rail-noise-and-vibration-impact-on-aquarium-sea-life/

I will underline the interesting bit below.

Quote

Bony Fishes

Fishes are subdivided into two categories, hearing generalists and hearing specialists. Hearing specialists have a lower hearing threshold than hearing generalists, making them more susceptible to noise in their environment.  Hearing generalists generally detect sound at levels no higher than 1 to 1.5 kHz, whereas specialists are generally able to detect sounds above 1.5 kHz.

Studies determining the effects of long term exposure to noise have been performed on hearing generalists and specialists. During these studies, hearing generalists were exposed to moderate sound levels (170-180 dB), and little effect was found on the generalists. Hearing specialists were exposed to similar sound levels (170 dB) and suffered hearing loss. Hearing loss and recovery is dependent on duration of exposure; in test cases there was a 5 dB temporary threshold shift after only ten minutes of exposure .  Several other studies have recommended that for long term exposure to noise, noise levels should be kept below 150 dB in order to eliminate hearing damage.

Sharks

Most published studies looking at the effects of noise and vibration on sharks used lemon sharks as the basis for their analysis, (as is the case with this report). Noise and vibration can be detected by sharks in two ways; with their ears and through the use of their lateral lines.

Auditory Responses of Sharks

Sharks are classified as hearing generalists, as they can generally hear noise up to only 1000 Hz. This is a general range which is applied to rays, sharks, and skates and is likely to be different depending on the specific species of shark (either increasing or decreasing the hearing range).

Studies performed by A. Peter Klimley and Arthur A. Myrberg, Jr. (1978) determined the acoustic stimuli underlying a withdrawal response from a sound source by adult lemon sharks. During this testing, broadband ambient noise levels were measured at 105 dB.  The lemon sharks were then exposed to several different noise sources.  If the shark retreated from the source upon being exposed to the noise, it was counted as a withdrawal response.  The sharks exhibited withdrawals 33% of the time at noise levels which exceeded the ambient noise by 30 dB (ie 135 dB).  The lemon sharks exhibited withdrawals 66% of the time at noise levels which exceeded ambient sound levels by 33 dB (ie 138 dB). 

During testing conducted by Banner and Hyatt (1973), the viability of eggs in one particular species of fish was reduced when exposed to noise of 105-120 dB at a frequency of 40-1000 Hz. These sound levels were maintained for several consecutive days .  No studies were found on the effects on reproduction due to intermittent sounds.

Low Frequency Rumble and Lateral Lines of Sharks

Lateral lines are fluid filled tubes lined with tiny hairs, which are stimulated due to changes in fluid particle motion. The lateral line is used to determine current direction and the location of objects present in the water.

As a result, Ripley’s animal husbandry department was initially cautious and apprehensive about whether or not the lateral lines of the sharks could be affected by the low frequency rumble (63Hz) of the passing trains. However, while the lateral lines of sharks are sensitive to signals from below 1 Hz to several hundred Hz, the lateral line is most sensitive to stimuli which occur within several body lengths of the animal , and thus are more attracted to gross motion in the water as opposed to acoustical effects. We therefore did not anticipate that induced levels of rumble within the water of the tank would significantly affect the lateral line sensory system of the sharks.

I generally try to have my "display tank" in a place where it's out of the way but can be enjoyed away from a lot of people.  I can only imagine how something like the noise from a HoB or the noise from other things around the room would affect the fish longer term. I know they are sensitive to loud noises and it does make sense as to why.   The interesting thing for me is that I am trying to have the display tank be a breeding tank at this point in time.  I did remove some equipment and it's virtually silent now. The loudest piece of equipment is the wifi switches turning on and off through the day.  This also means that something like adding a rubber pad or something to muffle vibration on the tank is going to be pretty critical for me.  (if someone has something that I can get pre-cut, please share, If not, I'll have to get another yoga mat)

I wonder, something like sound proofing a fish room, or isolating the room from loud external noise, how much of an impact that might have for a species that doesn't spawn in high numbers or often.  Maybe that is one way to encourage or increase spawning for difficult projects.

Something to think about...

I'm also looking at my tanks with regards to the type of surface agitation and the noise tied to the size of the bubbles that are produced from the air system.  Might be nothing because it isn't "loud enough", but it is a variable for me simply because of something like the ziss bubble bio I enjoy the noise.  Removing it recently to a different tank showed me just how loud it really is.

....and just because it's an opportunity to share a cool shark picture. I give you one of my favorites.  Another one from Matt Draper. AMAZING photo.

Edited June 10, 2022 by nabokovfan87

[nabokovfan87]

Further reading:

Part 1: https://www.nrc.gov/docs/ML1434/ML14345A573.pdf

Part 2: https://www.researchgate.net/publication/253413309_Update_on_exposure_metrics_for_evaluation_of_effects_of_sound_on_fish

Part 3: https://onlinelibrary.wiley.com/doi/10.1111/j.1749-4877.2008.00134.x

Edited June 10, 2022 by nabokovfan87

[PineSong]

Ummm, that photo is a big NOPE. I do wonder about noise driving my fish crazy or stressing them out. The air pumps tend to migrate from vibration, and sometimes when I get up in the morning one or another of them will seem really loud to me, so I can only imagine how loud the vibrations are to the inhabitants of the tank. I reposition it and it goes back to being more quiet, to be repeated another day. Interesting that chronic noise might impact egg viability. 

[nabokovfan87]

On 6/11/2022 at 1:42 PM, PineSong said:

Ummm, that photo is a big NOPE.

😂 I am sorry if that photo causes a hint of fear response.  I understand it, but they are definitely one of the most misunterstood animals in the world.  There is a documentary that you've reminded me of, and I would love for you to check it out!  It's on disney plus and other places "Playing with Sharks" and it's about the woman who worked on and was pretty critical to the success of Jaws.  She didn't view it as a realistic movie in any capacity, others have this innate fear because of how good the movie is.

https://www.nytimes.com/2021/07/27/movies/valerie-taylor-jaws-shark.html

This better?  I was trying to find the one he had of an Oceanic Whitetip but it's so difficult to find some of his work.  I highly recommend checking his stuff out on Instagram if you like Photography.  I don't have one, but that's about the only place he posts stuff.


 

On 6/11/2022 at 1:42 PM, PineSong said:

I do wonder about noise driving my fish crazy or stressing them out. The air pumps tend to migrate from vibration, and sometimes when I get up in the morning one or another of them will seem really loud to me, so I can only imagine how loud the vibrations are to the inhabitants of the tank. I reposition it and it goes back to being more quiet, to be repeated another day. Interesting that chronic noise might impact egg viability. 

I had to 😩 when I got to the end of the article.  Their study showed at 133 db the sharks had a very strong response against the noise.  At 135+ they suffered hearing damage.  So they decided to design the enclosure for 133 db.  Not something with buffer like 110, 120, etc.  Just weird to me.

Anyways, yeah, it's an interesting topic but I wanted to share it because I know so many people (and myself) struggle with breeding and some species don't have high spawn rates.  It might make a difference in efforts, it might not, but it's something cool to note.

I have noticed fish behavior being... unhappy when I have the TV next to a tank or music on in the room.  They tend to hide and tend to show some negative signs.  I do as a result of that turn things down or go to other rooms to listen.

Edited June 11, 2022 by nabokovfan87

[SandSea]

interesting article, thx 4 sharing