DALLAS (AP) - Like a lot of seniors, Jenny has some joint issues and her eyesight isn't what it used to be. But she still looks pretty good for an old -- gorilla. The ape celebrated her 55th birthday yesterday at the Dallas Zoo. The experts say Jenny is the world's oldest gorilla in captivity. Jenny had a four-layer frozen fruit cake. Her human visitors got chocolate and vanilla birthday cake, as they watched Jenny through the glass at the zoo's Wilds of Africa exhibit. Gorillas in the wild usually don't live past 35. So, what accounts for Jenny's longevity? She's not saying but her vegetarian diet couldn't hurt. Zoo keepers say Jenny loves her bananas, peels and all.