Vets at a Polish zoo have finally got to the bottom of why two caimans that have been mating for nearly half a century have never managed to produce any offspring.
Unfortunately for the male, it's not her, it's him. His penis is simply too small.
Yes, Hektor and Luiza - the caimans in question - have been together for not too far off 50 years in the Poznan Zoo in Poland. That's longer than most human relationships, but they have never managed to produce a miniature crocodilian of their own.
The pair met when they were only small back in 1973. However, it appears as if Hektor never really - well - grew into himself. Despite the pair having been observed mating vociferously every year since then, nothing has ever come of it.
Hektor simply can't seem to fertilise the eggs laid by Luiza, and now the vets at the zoo think they know why.
Malgorzata Chodyla, a representative from the zoo, said: "Eggs were produced several times, but nothing came of it.
"Our staff had no idea what was the reason for the failure. The truth only came to light during the visit of specialist doctors from Germany.
"Hektor needed a lot of research and consultation from a gastrologist because he did not have any appetite.
"It turned out he was fine. However, the reason for his infertility came to light. The doctors said it was not surprising that Hektor's efforts were futile, because his willy is too small.
"Hektor is always very loud and hundreds of visitors come to see him moan and groan."
Poor Hektor, and know the whole world knows about his troubles. Life's just not fair, eh mate?
There's no happy ending to this story, either - it turns out that they aren't even suitable candidates for IVF treatment. At least they've got each other.
Ms Chodyla continued: "Apart from the fact that Hektor and Luiza are already too old, this is an expensive procedure that is used only for endangered species."
Ah well. At least Hektor and Luiza have other things to concentrate on. In fact, they're a bit unusual by caiman standards.
The fact that they've been together for so long is remarkable in its own right. Caimans in the wild don't actually pair up for life. That makes the 46-year-long relationship between these two something extra special.
Unfortunately though, the size of a reptile's penis is pretty important when mating, which is why they've not been able to have kids. Still, that presumably won't stop them from trying.
Maybe, just maybe, they'll get lucky one day.
Featured Image Credit: CEN/Zoo PoznanTopics: Interesting, Weird, Animals