Recent Fish Otoliths

[Coco]

RECENT FISH OTOLITHS

The fish otoliths are situated in the head, and allow them in particular to be well situated in their environment.

They have three pairs of them, but the only one is of sufficient size to be found. They are formed by calcite, every day a very fine layer settles above. This explains that they are not completely similar from a fish to other one for the same species, according to its age. Each species has its own shape otoliths. It is a criterion of identification (that we try to use for the fossil otoliths), but when I see the big resemblance between certain common species, I indeed wonder how we can determine certainly the owners of fossil otoliths! I remain perplexed in view of what I found in the heads of my fishmonger fishes, in spite of the fact that in the past, the species were much less numerous than now...

Other very important thing : otoliths are not bigger in a big species fish than in small grown-up fishes ; on the contrary... That deceives enormously ! For example, among fishes from which I extracted otoliths, they are big at the whiting in the prorata of its size, whereas the salmon otoliths are really small, to the point that in the first heads I did not find them !

I had a lot of difficulty finding a technique to extract mackerel otoliths. I have not yet managed to take out an intact pair, because they are very small, very fragile and I break them... It is also complicated at the salmons because it is too small, but I re-try regularly. I am going to arrive there !

I noticed that to flatfish, which have a small head, they are often big for the volume of the skull. So I tried with wedge sole Dicologoglossa cuneata,(small flatfish maxi 15 cm long) without too much hope. I found them on all !

Ahhh! What it is necessary of perseverance to extract otoliths ! And it is necessary to want it also ! (It is some ... fish).

OK, I know, I hear you : "and where are the pics ? THE PIIICS ! Here are, In the order of appearance :

- monk (anglerfish) - (Lophius pistacorius),

- pollack (lythe) (Pollachius pollachius),

- saithe (coley, coalfish) (Pollachius virens),

- ling (Molva molva),

- pout (pouting) (Trisopterus luscus),

- tub gurnard (Trigla lucerna).

Since the taking of these photos, I found :

- wedge sole (Dicologoglossa cuneata),

- king of the breams (Pagellus bogaraveo),

- grey gurnard (Eutrigla gurnardus),

- whiting (Merlangius merlangus),

- common mackerel (Scomber scombrus),

- european hake (Merluccius merluccius),

- european place (Pleuronectes platessa),

- dory (john dory) (Zeus faber) - Very small, but formed of flat helix in 3 points),

- dover sole (Solea solea),

- Atlantic salmon (Salmo salar).

Here is ! I consider good not to stop there, but to continue to go to search the big garbage can of my fishmonger in public (on the market)... When it is too full, I do not sink into !

It is a very interesting subject which can learn us a lot ! At the moment I limit myself to marine fishes, but when I shall have made all the species of the sea I can have, I shall attack freshwater otoliths. But there is a lot of work to make there before ! My fishmonger and his staff already take me for a bizarre girl with the skates and the sharks, but there they are downright going to find me infréquentable - not normal !).

Here is ! I consider good not to stop there, but to continue to go to search the big garbage can of my fishmonger in public (on the market)... When it is too full, I do not sink into !

It is a very interesting subject which can learn us a lot ! At the moment I limit myself to marine fishes, but when I shall have made all the species of the sea I can have, I shall attack freshwater otoliths. But there is a lot of work to make there before ! My fishmonger and his staff already take me for a bizarre girl with the skates and the sharks, but there they are downright going to find me infréquentable - not normal !).

Thanks to have read to me up to the end, in spite of my english which is only averagely voucher !

Coco

[Auspex]

A fascinating topic! I am most impressed with your ardor and determination to do this difficult research

[fig rocks]

How interesting, thanks for sharing Coco!

[bubonius]

Hy coco,this matter is really interested

This is an important way to compare the limit of existence of a living species,

In fact I also collect many otholites fossils and make a comparison with those living today,

actually is a project that I abandoned because the difficulty for me is huge, like you said, the size of otholites is not proportional to that of fish and thus reconstruct a paleo environment is not easy,

an example that impressed me at all is when I participated in the 'university for a study on the census of Xiphias gladius (sword fish) in the Mediterranean, in fact, among many things, we also studied its otholites and these are a few mm in specimens over 220 lbs!

however I possess still many otholites of living species in the Mediterranean and many fossil species (some managed to match)

I also have many Italian and foreign publications about the otholites (living and fossil too) if you are interested I send this to you with pleasure

[Coco]

Hello,

Bubonius, it's cool ! I am interested in your publications (Italian or other language).

I have some publications on otoliths (Dirk Nolf and others) in PDF files, or in paper. Perhaps it could be good to send us our lists to compare what each of us have.

I have several species of recent otoliths I can send you. If you are interested in, just let me know and I will prepare the list of what I can prep for you.

Coco

[bubonius]

ok i send PM

[Shamalama]

Great post, Coco. I have a question about Otoliths... what the heck does the fish use them for?

[Coco]

Hi !

Bubonus, I answered

Thanks Shamalama. I'm not sure I understand your question, but perhaps you want to know why fishes have otoliths, won't you ?

I do not know exactly which is their use, But I believe that they are useful for them for remaining straight ahead in the water, as for us at the level of the balance, we stand thanks to our hammer and our anvil in every ear.

I have a french friend who has to explain to me to what they are of use for fishes, I expect from his news and I shall announce you it with pleasure when I would have the answer.

Coco

[Ramo]

I have a collection of otoliths from freshwater drum. I have found that sometimes a 1 lb drum will have bigger otoliths than a 7-8 lb drum. (Not very often but occasionally, usually the bigger fish have bigger otoliths) Have you found this to be true with the otoliths you have collected from various species? I have often wondered if the bigger fish with smaller otoliths are just younger fish that were a little more successful than their smaller cousins?

[Coco]

Bowkill, je ne sais pas wat est «tambour d'eau douce". Est-ce une espèce de poisson? Si oui, savez-vous de son nom latin s'il vous plaît, ou bien vous avez une image s'il vous plaît?

J'ai trouvé des otolithes dans environ 15 Trisopterus luscus, Et ils ont la même taille. Les otolithes ont la même taille dans chacun d'eux.

À propos de Merlangius merlangus et Merluccius merluccius, Les otolithes sont plus petits dans des spécimens de petites et plus forte sur les grosses ... Je n'ai pas vu ce que vous expliquer sur l'espèce que j'avais, mais les miens sont les poissons de mer!

*********************************

I just found otoliths pics made by a friend (Thanks to Olivier !). Here are (fishes names are on them).

A "stéréomicroscopie" pic :

Stéréomicroscopie : binocular magnifying glass in passed on light, lighting on the bottom (in transparency)

Coco

[Auspex]

I always thought that otoliths were a fish's "inertial guidance system", keeping tabs on their orientation and changes in direction.

[Dave pom Allen]

very interesting topic, thanks for the lessen.

[Ramo]

Coco, could you please translate that last post? The only thing I could read was my name!

[Auspex]

Coco, could you please translate that last post? The only thing I could read was my name!

Google Translate:

Bowkill, I do not know wat is "freshwater drum." Is this a kind of fish? If yes, do you know its Latin name please, or you have a picture if you please?

I found in about 15 otoliths Trisopterus luscus And they have the same size. The otoliths are the same size in each.

About Merlangius and merlangus Merluccius merluccius, the otoliths are smaller in specimens of small and stronger on the big ... I have not seen you explain the kind I had, but mine are saltwater fish!

[Ramo]

Thanks Auspex!

Freshwater Drum: Aplodinotus grunniens

People around here refer to the otoliths as "Drum stones"

Ramo

I'm not smart enough to copy a photo from the internet and post it here, but I typed "fresh water Drum stones" into a google image search, and found a few photos there.

Edited December 16, 2009 by bowkill

[pleecan]

This is me holding a giant Freshwater Drum (shame fish) caught this fall in the Bay Of Quinte ON while fishing for walleye. PL

[Ramo]

All drum are caught while fishing for walleye, aren't they?

By the way, somewhere I have a picture of one I caught that went 21 lbs back in the 1980's. Wish I had taken the stones out of that one but I didn't. I still remember pulling it up and thinking I had caught some kind of giant ocean fish. (I do have a "master angler" award issued by the state of Kansas for it!)

Edited December 16, 2009 by bowkill

[Coco]

Hello,

Ohhh ! Sorry Bowkill ! My automatical translator does sometimes jokes with me !

Thanks to Auspex for translation. Automatical translator doesn't work very well, the good translation is :

Bowkill, I do not know wat is "freshwater drum." Is this a kind of fish? If yes, do you know its Latin name please, or if you have a picture please?

I found otoliths in about 15 Trisopterus luscus, and they have the same size. The otoliths are the same size in each.

About Merlangius merlangus and Merluccius merluccius, the otoliths are smaller in small specimens and stronger on the big ones ... I have not seen what you explain on the species I had, but mine are saltwater fish !

Bowkill, thanks for the latin name. I don't think we have your fish on our freshwaters.

A friend told me that : when a fish swims of fault, he "shines" for the eyes of its predators. Its otoliths are of use to it for remaining straight in the water and so the sun does not make its scales shine. I also wonder if otoliths do not serve in the migration of fishes, but it is just an idea to me, unfounded.

Coco

[Coco]

Pleecan, I think your big fish had big otoliths !

Coco

[pleecan]

Pleecan, I think your big fish had big otoliths !

Coco

I did released the spawning female fish .... she swam off otoliths fully intact ( a lot of people simply kill these fish as they are consider a garbage fish)! PL

Edited December 16, 2009 by pleecan

[Coco]

Hi,

Here is a PDF file about otoliths of recent fishes. It is in french, but there are a lot of draws and pics at the end.

http://www.wetlands.org/LinkClick.aspx?fileticket=Bn0bEP3TypM%3D&tabid=56

Coco

[Dicranurus]

Nice job Coco! Very interesting topic.

[Coco]

Since I began this subject, I acquired pairs of otoliths of numerous species (partially by Marine Bio), and they were recently photographed by a friend, Olivier. I refocused them, I recut them in a correct size, and put the legends.

I am going to be able to add these photos soon !

Coco

[Herb]

Coco, I have a sample of U.Cretaceous material from Mississippi (USA) with lots of ootoliths in it. If you would like some PM me with your mailing address..

[Herb]

Fresh water drum( croakers) are found in most warm water rivers through out the USA. They are supposed to be good to eat.