What does the Latin Fundulopanchax mean, besides "bottom"?

It is a composite name. According to one of Al Klee's articles Fundulus were east coast North American fishes that fled to the bottom or dove into the mud when threatened. That is pretty common among small fish & Klee pointed out that not all of those early "Fundulus" were killies. As other species were sorted out, fishes like Fundulus dispar and the mummichog, F. heteroclitus remained. While they too dive into mud if threatened, ironically they spend a lot of time cruising the surface for insects such as egg laying mosquitos and new born grasshoppers with a bad sense of direction.

Indeed they are also called topminnows and that is more descriptive. Many of them also have that spot on the head & are called star heads. In India, in a case of convergent evolution, the Aplocheilus like lineatus have a spot on the top of the head. Scheel suggested that even offered some detection of a shadow - a good thing in a world of cranes, herons, egrets & kingfishers.

Don't know if the Fundulus spot is light sensitive. It makes them pretty easy to spot for aquarists & presumably other predators.

A Dutch word for ditch, canal or stream used a lot in the 1600s in New Netherlands (taking in parts of NY, NJ, Connecticut & Delaware & their water sheds)) was kill. So the surface "minnows" also became fishes of the kill or eventually killies.

Once jumped out of the suddenly stopped car to snap a shot of the sign designating a stream "Fish Kill" in western Massachusetts.

The name works better where other languages are spoken. Probably a numbers of killie nuts have mentioned their preferences in the company of other aquarists only to have someone sidle up and ask, "So you keep & breed piranhas?"

Scheel may have mentioned the origin of Panchax, but Die Hechtlinge, by Dr. Werner Neumann, in his book on the Pikelings or Hechlings (Aplocheilus, Epiplatys & Pachypanchax) traces the name panchax in Bengal/ Bengladesh. In Bengali the people call that fish panchax.

Today it is Aplocheilus panchax. But because the species ranges from the Ganges delta in Pakistan across India & SE Asia to at least Bali in Indonesia, it must have a lot of popular names. It also has collected a lot of scientific names as scientists of different languages and ethnicities described it.

At one time they were put into Esox, the genus of the Northern pikes. Looking at them, that makes a lot of sense. As they were studied more they were put into a genus Panchax & so the Bengali fish was Panchax panchax. There was a trend in the early 1900s to lump many killifish into Haplocheilus. As killies were reclassified in other genus, that name became Aplocheilus. Maybe some English guy dropped his "h"s.

A number of the genus spun off from Fundulus (which was assigned in some early descriptions even of African killies) and Haplocheilus included panchax in the name. Dr. George S Meyers (1924) spun Fundulopanchax out of Haplocheilus for some African fishes, though the genus as he described it included a lot of killies (like bivs) in other genus now.

With the description of Aphyosemion (flagtails) the Fundulopanchax were mostly included in Aphyosemion. Lynn Parenti in 1981 made the more robust Aphyosemion a full genus as Fundulopanchsx. Spoecies are still being bounced back & forth as new DNA work comes out. That is still not accepted by many Europeans who see Fundulopanchax as a sub-genus of Aphyosemion. (Be careful trying to buy a "new" killie until you know ALL of the names it is called by.)

See http://www.chromaphyo.legtux.org/uploads/file/Collier.pdf

A fish shop owner. who was in killies long before I was, noted that before 1960/65, to the American wholesalers every killifish from the Eastern Hemisphere was a "Panchax". (Every killie from South America was a "Rivulus". Now even some Rivulus aren't Rivulus anymore.)

Probably more than you wanted to know about killie names. Ken Lazara in the KMI has a lot more to say about all this. Elsewhere he has a beautiful essay I can't find or I would have simply sent you there.

If you wish to pursue this further, do look at the KMI Oneline to the left on this page. Through Inter-library Loan (still free usually - actually your tax dollars already at work) or another killienut borrow JJ Scheel's Rivulins of the Old world (ROTW) or it's "second edition" of a sort, Atlas of Killifishes of the Old World.

All the best!