What species has the most ejaculate as a proportion of body mass?
Peter North. 
Also, what mammal.
I would guess a fish, though I wouldn’t know which particular species.
Q: What’s gray and comes in quarts?
A: Elephants
Why do I have a nagging feeling that I shouldn’t google this to find out who he is?
Don’t jump straight to Peter North. Start with Harry Reams and work your way up to him.
SSG Schwartz
Boy, I sure am glad you meant “greatest” as in “most”, rather than “best”…
Sperm whales.
That’s what instantly popped in my head when I read the thread title. I was about to say, “Well, I haven’t exactly sampled all of them”
I would vote for drosophila bifurca, which apparently “produces sperm that are more than 20 times the size of its body”.
Just don’t ask me why “fruit fly sperm” was an appropriate Google search, or why I remembered the article.
Drosophila bifurca produces the longest sperm whereas I think the OP is looking for quantity produced per ejaculation.
So if David Cronenberg had filmed Brundlefly having a wank, the sperm would have shot straight out of the studio onto the street.
I’m curious to know how the volume of ejaculate can be accurately measured, particularly in larger creatures such as elephants. I can’t envisage anyone checking out the contents of the female’s vagina following coitus, especially when:
Not to get too prurient here but is the only sure method of measuring the volume of elephant ejaculate to stimulate said elephant, possibly using soft core elephant pornography as an aid, and catch the stuff in a bucket?
It’s important to have a job that makes a difference.
Semen is collected from almost all domesticated animals, for use in artificial insemination. I would be rather surprised if this were not also the case for elephants. Tha apparatus is a bit more sophisticated than a magazine full of naked elephant cows and a bucket, though.
A guy dressed in some grey sweats, shaking his ass and playing a trombone?
My ex’s family were a bit like that.
In a previous artificial insemination thread, somebody linked to a site showing three styles of mock vaginas made for collecting horse sperm. Instead of Hot Mares magazine, a mare in heat (or the scent of one) was all it took to get him ready. Then Trigger, crazy with lust, is persuaded to mount a framework. Underneath, it is somebody’s job to hold a wood-and-leather faux horse pussy, and gather the semen.
“Quit whinin’, Clem. It’s your turn to wank the horse.”
Anyway, it’s safe to say it’s just a larger maneuver for an elephant. :eek: There really ought to be a kumquat joke in here somewhere, but I can’t quite bring it off.
Actually I’ve heard they get it from the ‘prostate massage’ method for elephants. Basically this guy puts a garbage bag over his arm, sticks his entire arm (like up to the shoulder) up the elephant’s rear and wiggles his arm around.
The best part is that the elephant knows this feels good and I’m pretty sure when he sees the dude with the arm-length glove on the elephant will start backing up toward him. 
Anyone interested in seeing this done should look at some of the Dirty Jobs reruns. Mike Rowe gets intimately involved with many different creatures. At one point, he was handling a sort of anal probe gadget that was connected to a fancy control panel. In another show, he got to use the aforementioned artificial horse vaginas. Truly amazing stuff.
Watch Freddy Got Fingered. Tom Green scrupulously observed scientific accuracy in this matter.