After an embarassingly long hiatus, I’m hoping to get back to answering questions this week.  A reader recently notified me that the contact and question submission forms weren’t working on the site.  I wondered why I wasn’t getting any questions anymore …

It should be fixed now.  If you have trouble, please email me at

Last week, some Ancistrus catfish, otherwise known as bushynose catfish, spawned in my fish tank, and the eggs began hatching over the weekend.  Using a nifty portable, USB microscope that takes pictures and video, I captured a clip of one of the little guys.  He/she is clinging to the side of the glass with its sucker mouth and I took the video through the glass.  So what you’re seeing in the video is the underside of the baby catfish.

What’s really cool is that just above the yolk sac you can see its tiny red heart beating furiously.  I never cease to be amazed that such a tiny creature (about 5mm, 3/8 inch)  can actually function.  How can a heart that tiny work and pump blood?  Amazing!

baby catfish snapshot

Click to see video

Ask a Naturalist® (December 4, 2023) Tiny Catfish Fry Heart. Retrieved from
"Tiny Catfish Fry Heart." Ask a Naturalist® - December 4, 2023,
Ask a Naturalist® February 7, 2011 Tiny Catfish Fry Heart., viewed December 4, 2023,<>
Ask a Naturalist® - Tiny Catfish Fry Heart. [Internet]. [Accessed December 4, 2023]. Available from:
"Tiny Catfish Fry Heart." Ask a Naturalist® - Accessed December 4, 2023.
"Tiny Catfish Fry Heart." Ask a Naturalist® [Online]. Available: [Accessed: December 4, 2023]