Paul, we both run similar sustems and have similar beliefs in what is best for our animals be it foods or their enviroment. A long time in this facinating hobby. Always learning, always something new no matter how small.
When I started how I have kept my tank and basically still do around 45years ago I never read of reports of spawnings of fish in hobbiests tanks. That is apart from clownfish. We had a couple of magazines here in the UK the premier one being Practical Fishkeeping known as PFK for short. We also had Tropical.Fish and Hobbiest magazine TFH for short, you know you will recall that one.
However, I don't recall any articles on fish spawning in any of those magazines apart from clowns. We had a nation wide marine fishkeepers group called The British Marine Aquarists Association, the BMAA for short.
I was prominent in the group and wrote many articles for it, no payment of course all contributions to the cause. I wrote mainly about my experiences with my aquarium, what I was doing and the results, much was DIY as DIY was quite prevalent back then.
I started experiencing spawning of my fish which were all small species. Apart from clown fish which also spawned for me others spawned like my pygmy angels, 6 lined wrasse, yellow tail blue damsels. Yellow coral gobbies (that spawned on the front glass of my aquarium), Royal grammas and Mandarins.
We had seminars like you have in the US and even had a few US speakers, Forest Young. Albert Thiel. Julian Sprung and in particular Martin Moe. I say in particular as Martin was very much into trying to raise Flame angels at the time having already raised Royal grammas. We had a good chat after he had read my article on the spawning of my Mandarins in which he showed a lot of interest.
Of course I never raised any of those fish, in fact I neither had the time, inclination nor expertise. I did however managed to catch some Cherub pygmy angel eggs one evening when they spawned ( Centropygi argi). I give them to a friend of mine who managed to raise a couple of them but that is abother story.
The big issue in raising foods was finding and raising the correct live foods. All we had were rotifers and brine shrimp nupli nothing else. They were far too large for very small fish fry.
My friend was at Liverpool University studying marine biology and had the resources of the university us more to cultivate much smaller foods. Like I say that is a different story for another time.
Many will think spawning of ornamental marine fish in aquariums is a relatively new thing. Only the rearing and breakthrough in foods is really new not the spawnings.
