Abstract
Despite being one of the most popular seahorse species displayed in public aquaria, hematologic reference intervals have not yet been established in big-bellied seahorses (Hippocampus abdominalis).1 The objectives of this study were to establish hematologic reference intervals in this species, and to compare white blood cell counts obtained via the Natt and Herrick technique versus an estimate on blood smears. Forty-three healthy individuals from the Aquarium du Québec (22 females and 21 males) aged 6 to 8 months were included. Health status was assessed by unremarkable physical examination of 5 randomly selected individuals and complete necropsy of 5 additional specimens. Weekly water-quality checks were carried out in each tank. All animals were identified with visible implant elastomer tags. Venipuncture was performed from the ventral coccygeal vein in 33 individuals, without anesthesia, using heparinized insulin syringes. A blood volume of 0.05 to 0.1 ml was collected to obtain blood smears and microhematocrits in 25 individuals. Whole blood was stored in heparinized Eppendorf tubes to perform red and white blood cell counts using the Natt and Herricks technique for 10 individuals, and blood smears were obtained for comparison. Blood smears were stained with Wright Giemsa, alkaline phosphatase, periodic acid-Schiff, and toluidine blue to further characterize cells. Packed cell volume reference interval is 28.5–67.5%, which is higher than the values reported in Hippocampus erectus.2 White blood cell and platelets counts reference intervals will be presented. These reference intervals may help assess the health of seahorses under human care.
Acknowledgements
The authors wish to thank the animal health technicians of the Aquarium du Québec, as well as the Centre Québécois pour la Santé des Animaux Sauvage (CQSAS) for their contribution to this project.
*Presenting author
+Student presenter
Literature Cited
1. Koldewey H, Mulligan M, Shedd J. 2005. Syngnathid Husbandry in Public Aquariums—2005 Manual. London: ZSL. 137 p.
2. Anderson P, Berzins I, Fogarty F, Hamlin H, Guillette L. 2011. Sound, stress, and seahorses: the consequences of a noisy environment to animal health. Aquaculture. 311(1–4):129–138.