This comes up every month or so. And not surprisingly so. You'll find people are going to tell you what they're used to hearing. It's natural, but often completely incorrect. I got into a rather heated debate about this, last go 'round. I promise I won't do it this time. However, I will tell you what I believe to be correct (with a tad of explication) and leave it at that.
Chaetomorph is the scientific name. The scientific language follows rules within a Latin or Latinized structure, often including pronunciation. Yet, as like the rest of the world, it's never totally cut and dry. Like many scientific names,
Chaetomorpha comes from the Greek, as noted above by LockeOak. And, as is the case with many Greek derived scientific names (e.g. chlorine, chlorophyl, chloride) the "ch" is pronounced like a hard "c" or "k".
One might guess the "ae" part pronounced like the dypthong, long "i" sound, but it is not. It is pronounced like a long "e".
And so finally, we have, as posted earlier, "key-toe-more-fah"
I promised to myself this is my one and only post in this thread.

On the other hand, I really don't care how others pronounce it. Some advice in the past was pronouce it the way your boss does.:rollface: