Eels

[Gary Knowels]

I had a student tell me something yesterday that tripped my "internet nonsense" detector. Apparently they watched some TikTok video that claimed we (the body of science) doesn't know how eels reproduce.

I did a quick Google search, found out this was nonsense and then fell into a rabbit hole of eel learning.

Apparently the video claim came from the idea that scientists had not provided concrete evidence about the spawning grounds of European eels. It was previously known that they migrate southwest passed the Azores, and suspected that they ended up in the Sargasso Sea near Bermuda and that was confirmed in the last couple of years with GPS tagging. That's a long ways to go to spawn!

Some other things I learned about eels during this
They have a catadromous lifecycle (opposite of anadromous)
Eggs hatch within a week of laying
the eggs are bouyant and fertilized in open water in some sort of mass mating
They have some unique life stages including a larval stage(leptocephalus) and a transparent glass eel stage in saltwater before returning to river to live and grow.
They are predatory and opportunistic
They can live upwards of 20 years
American eels also spawn in the Sargasso sea (do they have spatial or temporal spawning differences? Can they interbreed a la cutbows?)

Anyways, eels are cool and I learned a lot yesterday.

 

[TicTokCroc]

Yea I went down the eel rabbit hole when I watched some u toob videos about eel buyers on the east coast. They buy the glass eels as they out migrate then Send them to Asia to be reared commercially... then a large portion get sent back so we can eat eel sushi.

 

[Gary Knowels]

Yea I went down the eel rabbit hole when I watched some u toob videos about eel buyers on the east coast. They buy the glass eels as they out migrate then Send them to Asia to be reared commercially... then a large portion get sent back so we can eat eel sushi.

Years ago there was a program called Filthy Riches that profiled a guy in New Year that built a weir to capture out migrating eels on the Delaware river to smoke and sell, which I thought was cool.

The glass eels would be migrating towards rivers. I do love me some unagi though. I didn't realize that some were American eels and not Japanese eels. I wonder how they compare.

 

[Matt B]

Eels are cool. I enjoyed both of these:

The Mystery of Eels ~ Book Excerpt: Eels by James Prosek | Nature | PBS

Prosek sets out to tell the story of the world's most mysterious fish.

www.pbs.org

 

[DoesItFloat]

Did somebody say IMPOTENT SEA SNAKES ?!?!?!?

 

[RCF]

Years ago there was a program called Filthy Riches that profiled a guy in New Year that built a weir to capture out migrating eels on the Delaware river to smoke and sell, which I thought was cool.

The glass eels would be migrating towards rivers. I do love me some unagi though. I didn't realize that some were American eels and not Japanese eels. I wonder how they compare.

Loved the show "Filthy Riches". Brings back fond memories...

 

[Gary Knowels]

Loved the show "Filthy Riches". Brings back fond memories...

The ginseng family was the funniest, their reality felt like satire the entire time. The Maine wormers might have been my favorite though.

 

[VAGABOND]

Hellacious Striped Bass / Rockfish (depending upon where you reside) bait. Should be illegal they’re so deadly.
If you float the Delaware main stem you’ll occasionally come across their nests in calmer water just off the main current. Neat mounds of stones. Looks as if your child decided to collect smooth rocks and make a neat pile.

There was a story some years back in the NYT about the netting and harvesting of American eels that were migrating out of rivers in Maine heading for the Sargasso. It appeared there were some nefarious characters involved in net stealing, gun fire, Bolivian Marching Powder, huge wads of cash, along with broken noses and other mayhem due to the fact of huge demand in Asia. Read: non reported income in small town locales.

 

[Chucker]

Also a good book about eels. Same title as the other one, different author.



The truth about the eel reproduction mystery is that nobody has actually seen them mating. Speculation is that it happens in deep water below the Sargasso Sea.

 

[TicTokCroc]

There is a company on the east coast trying to figure that mystery out. If they can figure out how to rear eel commercially in pens then they will make a fortune.

 

[Wetswinger]

There is a company on the east coast trying to figure that mystery out. If they can figure out how to rear eel commercially in pens then they will make a fortune.

God, man just has to try to find a way to profit off of everything, doesn't he...

 

[Kilchis]

God, man just has to try to find a way to profit off of everything, doesn't he...

I'll answer that question for 5 bucks plus $3.50 shipping and handling.

 

[Old406Kid]

I don't know much about eels but what I do know is that it's not a good idea to wade out waist deep with shrimp in the pocket of your shorts.

 

[TicTokCroc]

God, man just has to try to find a way to profit off of everything, doesn't he...

In this case I think it would help with conservation. The glass eels are dipped out of the river like smelt, bagged and sold to eel dealers who pay thousands of dollars. I don't think there's any oversight at all.

 

[Wade Rivers]

I had a student tell me something yesterday that tripped my "internet nonsense" detector. Apparently they watched some TikTok video that claimed we (the body of science) doesn't know how eels reproduce.

I did a quick Google search, found out this was nonsense and then fell into a rabbit hole of eel learning.

Apparently the video claim came from the idea that scientists had not provided concrete evidence about the spawning grounds of European eels. It was previously known that they migrate southwest passed the Azores, and suspected that they ended up in the Sargasso Sea near Bermuda and that was confirmed in the last couple of years with GPS tagging. That's a long ways to go to spawn!

Some other things I learned about eels during this
They have a catadromous lifecycle (opposite of anadromous)
Eggs hatch within a week of laying
the eggs are bouyant and fertilized in open water in some sort of mass mating
They have some unique life stages including a larval stage(leptocephalus) and a transparent glass eel stage in saltwater before returning to river to live and grow.
They are predatory and opportunistic
They can live upwards of 20 years
American eels also spawn in the Sargasso sea (do they have spatial or temporal spawning differences? Can they interbreed a la cutbows?)

Anyways, eels are cool and I learned a lot yesterday.

The Pacific Lamprey has a complicated lifecycle too. Plus there are jillions of brook lamprey living in the substrate of our rivers and creeks.

https://www.dfw.state.or.us/fish/species/docs/lamprey/LampreyTrifold.pdf

Fun facts: Lamprey are not "eels" and are a clean water indicator species.

 

[Zak]

The Pacific Lamprey has a complicated lifecycle too. Plus there are jillions of brook lamprey living in the substrate of our rivers and creeks.

https://www.dfw.state.or.us/fish/species/docs/lamprey/LampreyTrifold.pdf

Fun facts: Lamprey are not "eels" and are a clean water indicator species.

My son found four dead lamprey in the Snoqualmie River today. Neither of us know much about them. Any idea what species these are, and what might have killed a bunch of them? I was guessing some kind of treatment for exotic species? Or maybe someone was using them as bait? Here's a picture:

 

[Stonedfish]

My son found four dead lamprey in the Snoqualmie River today. Neither of us know much about them. Any idea what species these are, and what might have killed a bunch of them? I was guessing some kind of treatment for exotic species? Or maybe someone was using them as bait? Here's a picture:
View attachment 111771

Maybe they died after spawning?
SF

 

[Nick Clayton]

Never been a big fan of eels. Remind me too much of snakes, and God I hate snakes.

While not technically an eel, there are some wolf eel caught out of Westport every year, and quite frankly those things kinda scare the shit out of me lol. Gnarly creatures. Never caught one on my boat, and honestly I'd be happy to keep it that way.

Snakes of the sea, no thanks!

 

[Zak]

Maybe they died after spawning?
SF

Based on the trifold that @Wade Rivers posted above, I think you are right. The color matches the Pacific Lamprey, but the trifold says they get to be 33" long and these were about 12" long or less.

 

[Cabezon]

There are three lamprey species in Washington: Pacific lamprey (Entosphenus tridentatus - up to 31" long, Western river lamprey (Lampetra ayresii - up to 12" long) and Western brook lamprey (Lampetra richardsoni - up to 7" long). All three species are likely found in the Snohomish system. Without being any kind of lamprey expert, I would say that these carcasses are Western river lamprey based only on size.
Only the Pacific lamprey is anadromous (post-juveniles spend parts of their lives in the Pacific Ocean) and it is the only species that is parasitic: feeding the body fluids of other fishes [wrong on both scores as Western river lamprey has a similar life cycle and feeding ecology.]. The Western river lamprey and the Western brook lamprey spend their entire lives in freshwater [correction: nope, just the Western brook lamprey lives exclusively in freshwater]. Both are filter-feeders [correction: nope, only the Western brook lamprey.] that consume algae, such as diatoms, and other microorganisms from freshwater sediments. [Correction: As @Smalma points out in a later contribution, the Western river lamprey is actually parasitic as an adult and is also anadromous.]
All lampreys, like salmon and Anguillid eels (European eel, American eel, Japanese eel, etc.), are semelparous = breed once and then die. According to this WDFW web site, the lamprey breeding season in Washington is typically April to July, but it can be earlier if the stream temperatures are warmer. Males and females work together to build a nest (like a salmon redd) and the eggs are deposited in the sediment.
Regarding eels, here is a fascinating article on research efforts, both present day and historical (Sigmund Freud, even...) to understand their reproduction: how, where, etc. In light of their cultural and gastronomic importance (and crashing populations), the Japanese government has supported intense research efforts and these have been successful. The Japanese scientists have collected eggs and 2-5 day old larvae at depths of 450-600' on dark new moon nights near the Mariana Islands to which the adult migrate.
We have no "true eels" = Anguillidae in Washington state. Anything with the common name "eel" that you find in Washington, such as the monkeyface prickleback or monkeyface eel, is simply a fish with an elongated body.
Steve