Trichechidae (Manatee)

The order Sirenia is currently composed of the families Trichechidae and Dugongidae. This chapter focuses on the American manatee, particularly the Florida manatee subspecies. Many adult manatees rest quietly during image acquisition; however, some individuals require sedation. All Sirenians have a relatively small head and neck, transitioning into a broad trunk that tapers into a peduncle and paddle. The axial skeleton of manatees is unique, with short cervical and lumbar regions and elongated thoracic and caudal regions. Entanglement with marine debris is a common threat to manatees. Manatees are herbivores and utilize a hindgut fermentation digestive strategy. The gastrointestinal tract consists of a simple, saccular, C-shaped stomach with a distinct gastric ridge and a discrete accessory digestive gland. Gastroenteritis is a common finding in orphaned manatee calves.