Friday, May 5, 2017

"Parasite living inside fish eyeball controls its behaviour"

Via RedditA common parasite that lives in fish eyeballs seems to be a driver behind the fish’s behaviour, pulling the strings from inside its eyes.

When the parasite is young, it helps its host stay safe from predators. But once the parasite matures, it does everything it can to get that fish eaten by a bird and so continue its life cycle.

The eye fluke Diplostomum pseudospathaceum has a life cycle that takes place in three different types of animal. First, parasites mate in a bird’s digestive tract, shedding their eggs in its faeces. The eggs hatch in the water into larvae that seek out freshwater snails to infect. They grow and multiply inside the snails before being released into the water, ready to track down their next host, fish. The parasites then penetrate the skin of fish, and travel to the lens of the eye to hide out and grow. The fish then get eaten by a bird – and the cycle starts again.

Many parasites can change an animal’s behaviour to fit their own needs. Mice infected with the parasite Toxoplasma gondii, for example, lose their fear of cats – the animal the parasite needs to reproduce inside.

In a 2015 study, Mikhail Gopko at the Severtsov Institute of Ecology and Evolution in Moscow and his colleagues showed that fish infected with immature fluke larvae swam less actively than usual – making themselves less visible to predators – and were harder to catch with a net than uninfected controls.

Now, the same team has tested rainbow trout harbouring mature eye flukes – parasites ready to reproduce inside their bird hosts. The team found that these trout swam more actively than uninfected controls and stayed closer to the water’s surface.

Both traits should make fish more conspicuous to birds. When the researchers simulated a bird attack by making a shadow swoop over the tank, the fish froze – but infected fish resumed swimming sooner than uninfected ones.

Gopko says both studies show that how eye flukes manipulate their host’s behaviour depends on their age. Immature parasites “are too young and innocent to infect a next host”, he says, so their goal is to protect the fish they are living in. Mature parasites, however, are ready to reproduce – and to do so they need to get inside a bird’s gut.

(Link to more)

23 comments:

rcommal said...

No, Lem.

You are doing it wrong.

Full Stop.

rcommal said...

Since y'all insist on it, I've been parasite since 1960.

rcommal said...

Hey. Lem. You hate me. I get it.
I
What you don't get is that I've gotten so much more than people think, on account of my musician parent s [and my dad's grandpa].

rcommal said...

I'm listening to music that I collected even before I ever met you. Even before I met my husband.

rcommal said...

Honestly, you don't take good care of your own. You are more interested in Troop, for example.

rcommal said...

Lem:

You truly do not get the, quite literally, thousands of music and songs that I collected before you and I ever met.

What a mistake.

rcommal said...

Hey, Lem (and what is your exact age, anyway?):

Did you know that back in the '80s I worked in and for an independent TV station that helped launch Telemundo in the United States?

rcommal said...

It's on my old resume, and I can prove it.

AllenS said...

That parasite infects more than fish, evidently.

Evi L. Bloggerlady said...

Allen S, ain't that the truth!

Rabel said...

Sing it Patsy.

Chip Ahoy said...

rcommal, I don't know who you are, what your bag is, nor what bug crawled up your butt this morning but your two malevolently ill considered remarks are removed from my earlier post. And greetings to your dad who sounds a lot more interesting than you.

Fr Martin Fox said...

This could remedy what's wrong with Congress.

MamaM said...

Honestly, you don't take good care of your own.

Honestly, rcommal, good and loving care has been extended several times to you on this blog. It's shown up as respect in the face of disrespect, along with kindness, compassion and support offered in response to trauma revealed.

Intentional or not, repeatedly presenting oneself as a victim and others as uncaring perpetrators is a red flag that signals something is internally off center.

If jumping into that kind of drama is a game you enjoy playing by yourself in the early the morning hours, than I wish you God Speed and Good Luck, and will allow myself to laugh at the responses that game prompts from others.

The truth on my end is this: I find it hard to read your comments and accusations without wondering where they are coming from and what you truly need, want and wish to convey.

Sixty Grit said...

I had to repair my range top this week. That's not an easy task. I had inadvertently burned up one of the cooking elements (known as 'eyes' in the trade), and once I replaced it (not easy to find a replacement part for a 66 year old GE range, just sayin'), I discovered that I had also damaged the switch.

There are more ins and outs to this story, but I am still alive, so I am taking good care of my own.

Also, this morning, I was called upon to take care of a young Pit/Plott mix - she was being abused by her owner and I did what I could to rehome her. So I am also taking care of others, in addition to my own.

Now I am going to take care of myself by ceasing my defense. I am fine, we are good here, it has been a busy and productive week, with many products completed, walks taken, storms endured and now the sun is shining and all is right in my little corner of the world.

As you were.

Oh yeah, I can't help but be reminded of something Jonathan Winters said of Robin Williams' brain "It's crowded in there!"

Yeah, ol' Jonathan knew a fellow loony toon when he saw one.

Rabel said...

Hi Father Martin.

Sixty Grit said...

Willie Nelson sure could write 'em, couldn't he? And my former neighbor's ex-wife sure could sing, that's for true.

Fr Martin Fox said...

Hi Rabel!

AllenS said...

Good to see you again, Fr Martin Fox.

Fr Martin Fox said...

Thanks Allen.

ampersand said...

Good to see you posting, Father Fox.

Fr Martin Fox said...

Thanks!

cliff claven said...

Did you know the title priest derived from the Latin, presbyter? I'm sure Presbyter Martin Fox did.