The high level of market demand encourages intensive fishing activity, which can affect seahorse populations in nature, leading to a decline in the number of seahorse species. Seahorses are one of the marine animals that have a low survival rate. In the waters of Morotai Island, especially in the village of Sopi, the residents use seahorses as a tonic to enhance male stamina by mixing alcohol with dry seahorse extract and fermenting it. The problem in this study is the need for more research on sea horse data, covering  North Maluku and the waters of Morotai Island. The purpose of this study was to identify and analyze the long-weight relationship of seahorses in Morotai Island waters covering six sub-districts, including South Morotai, South-West Morotai, Rao Island, East Morotai, North Morotai, and Morotai Jaya. Data collection on seahorses from June 2022 to July 2023 utilized a purposive sampling method, which was conducted in the seahorse fishing area based on information collected from the local community. Data were gathered for 20 points in six sub-districts. Seahorses are caught using seser tools and snorkeling. The study results revealed the presence of three types of seahorses in the waters of Morotai Island, Hippocampus kellogi, Hippocampus kuda, and Hippocampus spinosissimus, each displaying distinct morphological form. In total, 25 sea horses were observed during the study. At the same time, the analysis of the long-weight relationship showed a positive allometric growth pattern with a value of 3.03 where weight gain was faster, compared to the body length.