Biggest Black Ghost Knife

[Josh's Fish]

Very interesting! Why would it lose it's eye over time? Does it then rely on the electrosensory organs?

I think it relies on that all its life, in its natural habitat eyes are pretty much useless anyway. I think it's kind of similar to other fish losing scales with age.

Yes, the eyes aren't really utilised by them at all throughout their life, except in case of maybe associating day/night by detecting light; but again this is a redundant feature, as Chromatophore cells throughout the body do this too. One of many reasons why blind creatures can still differentiate between night and day.

 

[Hendre]

Interesting, thank you! I keep African knives that are the complete opposite by relying on eyesight and not having dedicated electrical organs like South American knifefish.

 

[EntoStentor]

Really? African knives have no electrical organs whatsoever? Kinda defeats the whole purpose of being a knifefish...

 

[Josh's Fish]

Really? African knives have no electrical organs whatsoever? Kinda defeats the whole purpose of being a knifefish...

Why would that defeat the purpose of being a Knifefish? They are only named so by the shape of their body. It's only the South American Knifefish which are electrical. The Aba and Featherback Knifefish species which are more closer related Mormyrids are not electrical.

 

[CrazyKoiCracker]

Why would that defeat the purpose of being a Knifefish? They are only named so by the shape of their body. It's only the South American Knifefish which are electrical. The Aba and Featherback Knifefish species which are more closer related Mormyrids are not electrical.

::Sigh::
Aba Knife
Dream fish.

 

[Hendre]

Really? African knives have no electrical organs whatsoever? Kinda defeats the whole purpose of being a knifefish...

They rely on eyesight but have lateral lines for sensing prey.

Also as I have learnt the hard way; they have a very fragile heirarchy. One goes and the remaining two got killed off by the dominant one..

 

[Balistik928]

The original image is a forced perspective of a male that's been floating around for a few years (likely under 20 inch, 22-24" at absolute most). When they exceed 17-20 inch, the eyes are useless organs (could almost say vestigial) and the skin will either grow over them, or they lose those organs through atrophy. The original one pictured looks like it still has light reflecting off its lens, so it's difficult to believe this specimen is over 2ft; although I do believe this is a species which can very easily reach that size in time.

Here's one of mine after the eye becomes naturally atrophied.View attachment 1362858

So are you saying that they become less and less sensitive to light as they grow? Wow. I'd love to see mine more.
Here is a photo of him (I don't have a lot of these photos)

 

[EntoStentor]

You will see them a bit more, not because they are less sensitive to light, but because they get bolder. Ideally if you want to see them as much as possible have them by themselves. They get scared of the water movements caused by other fish. As they grow these will become smaller and smaller compared to the knifefish. At adult size they will also eat from your hand (check out Josh's Fish channel on youtube, same name. He has tons of feeding videos on there).

 

[blackbullhead]

It is true that Notopterids, including Asian and African knives don't have an electric discharge, but they are electroreceptive...meaning they can detect weak electric fields. Catfishes, South American knifefishes, and mormyrids can also do that. The aba aba is electrogenic like mormyrids and SA knives.

 

[jwitty]

It definitely doesn’t look much over 2’ like some have said. Compare how the fish is up by the camera while the guys leg is so far away. Plus the camera isn’t parallel with it. Although usually a shot down which is what this looks like, will make the object look smaller. I don’t think it’s the monster people are claiming. Maybe 20” max