Please meet my pet Terry (Terrapin - http://en.wikipedia.org/wiki/Terrapin), 15 years ago, Terry was as small as 50 cents (1.5"diameter) now, and it has grown up to almost 1 foot long. Terry eats vegetable, shrimps and small fish.
One fine morning, my son Litter V walked Terry out for a stroll in the garden, little brain got short memory, and Terry never been seen again.
3 months later, we found Terry buried himself in the ground with only his head partially exposed, attracting us by making pssi..pssi…pssi sound. Overcome with joy, we bath Terry and found him smaller in size. Never ever Terry was invited for a stroll anymore.
In Feng Shui, tortoise & turtle symbolise longevity, stability, strength, support and endurance. We place Terry in North corner as an enhancer for career, with the hope that it attracts a smooth, grounding energy for business projects and promotions in career.