Amazon River Dolphin: Inia geoffrensis

摘要: Publisher Summary This chapter explores the Amazon River dolphin commonly known as boto. It belongs to family Iniidae. The genus Inia is currently considered monospecific, with three recognized subspecies: geoffrensis , I. g. boliviensis and humboldtiana . boto largest of river dolphins a maximum recorded body length 255 cm mass 207 kg for males 225 approximately 153 females. also most sexually dimorphic dolphins, 16% longer 55% heavier than corpulent heavy but extremely flexible. Nonfused cervical vertebrae allow movements head in all directions. flukes are broad triangular; dorsal fin long, low, keel-shaped, extending from mid-body strong, laterally flattened caudal peduncle. flippers large, broad, paddle-like capable separate circular movements. Although these characteristics restrict speed during swimming, they this swim backward maneuver between trees submerged vegetation search food flooded forest. mostly solitary not seen cohesive groups. Group size generally one four individuals. Most groups two mother–calf pairs, mixed common.