2.5 Day Old Mandarin Dragonet Larva Learning to Hunt

A baby mandarin dragonet tries to hunt tiny moving specks (small copepods). The larvae is about 50 hours post hatch and about 62 hours post spawn, and it has only just become able to eat (mandarins have a prolarva stage where they don't yet have a digestive tract for their first couple of days of development.
The food are parvocalanus copepods that fit through a 250um screen, I don't yet know whether these guys will survive with those as their primary food source, but I've documented similarly sized other copepods being eaten by them.

[@cathy6188]

Hey! Thanks for the amazing video. Do you have a hatch tank set up video?
Hope your channel gets popular soon!

[@mdbssn]

It was a pretty basic setup - a 10 gallon brute trashcan with an airstone with a bubble or two a second, starting as fresh made saltwater. I had a cover over it to reduce evaporation, a seedling grow mat on the outside for heat, and a dim light overhead (I think on 24 hours in this case.)
I've moved to smaller containers with 3d printed things to round the corners more recently to make maintenance and spotting larvae easier, but I also haven't had a successful mandarin run since.

[@Ivanadg]

Is it parvocalanus best source of food for such a newborn fry ?

[@mdbssn]

At least for these guys, I don't think it's necessary. I haven't had a lot of success culturing parvocalanus in the long term, but it seems like most larvae don't need food as small as they can offer (the nauplii are smaller than most readily culturable copepods). I've heard mandarins have been raised off of artemia nauplii, which are much, much larger, and I had my little bit of success with a mix of tisbe, tigriopus, and apocyclops (cultured separately, but all offered.)