Dave,

Basically, you have three permanent seahorse (Hippocampus) species in your 'neck of the woods' and many others that are 'incidentals' that visit from time to time.

H. reidi - The Brazilian Seahorse can get to 6" at adulthood. More info on them here:

http://species.fishindex.com/species...sea_horse.html

H. erectus - another larger species growing to 6-8" at adulthood. They are found from New England to points further south than you. Some real nice pictures here:

http://www.oceanlight.com/lightbox.p...campus_erectus

H. zosterae - is the "Dwarf Seahorse" at adulthood is just 1 and 1/2" to 2" long an image can be seen here:

http://www.divegallery.com/seahorse10.jpg

Given that you had yours for a period of 9 months, and it got no larger than 1.5 inches. My guess is that you had yourself a Dwarf.

Dave