Recent content by gwand

I have 10 red coral dwarf Xiphophorus maculatus. One fish has a discolored swelling on each flank. Is this worms, a tumor, pregnancy etc?

There is a black wiggly thing by the gill.

I have not had a DOA in the last 25 fishes that were delivered by overnight UPS. In fact I can’t remember any DOA fishes sent by overnight UPS. But I am running about a 10% death rate during 4 weeks of quarantine. This year I mail ordered mostly from The Wet Spot and Aqua Imports. I use to buy...

This is my Bach program for next Sunday. PROGRAM BACH Orchestral Suite no. 2 in B minor BACH Cantata 182 (“Himmelskönig, sei willkommen”)

I’m the semi aquatic animal in my house that removes algae and dead plant matter. 😀

My childhood friend is here visiting with his wife. I have known him for 70 years. He was the person who encouraged me to become an aquarist. He has maintained a 250 gallon Lake Malawi tank for 50 years. I’m going to take him to my local fish store; the one with over 700 tanks. This will blow...

I have had no luck jump starting nitrogen cycles. I have tried Dr. Tim’s One and Only bacteria as well as Tetra’s bacteria. I have also used mature sponge filters. Bottom line: it still takes me 3-6 weeks to fully cycle a tank using 1 ppm ammonia.

We want a binary answer: yes, it is the same species; no, it is not the same species. However at end of the day, it is still an arbitrary process with agreement based on the necessity to reach a decision. Something we just have to live with. Maybe species is a man made artifact.

There is even a qualitative aspect to the seemingly quantitative technique of whole genome sequencing. The investigator decides when two DNA sequences are similar enough between two fishes to declare them the same or separate species. This is a somewhat arbitrary decision. I opine for the good...

Or the need for a uniformed nomenclature.

Ammonia exists in two forms in water: un-ionized ammonia (NH3+) and ionized ammonium (NH4+). The ratio between these two forms is determined by the water's pH level. At higher pH levels (more alkaline conditions), more ammonia exists in the toxic un-ionized form (NH3), which can easily injure...

This is an even more important finding than the previous article. https://phys.org/news/2025-10-zebrafish-spinal-cord-sophisticated-mechanism.html