Meeting Abstract
Several weeks after hatching, larval paddlefish begin to grow a rostrum; within a period of several more weeks, this extension of the cranium has grown to represent one-third of the total body length of juvenile fish. This remarkable allometric growth also includes elaboration of large numbers of well-described electrosensory ampullae on the rostrum surface. Less is known about the internal pair of lateral line canals that extend along the length of the rostrum. These canals are outgrowths of the cranial infraorbital canal and terminate at the rostrum tip. As the canals elongate with rostrum extension, mechanosensory neuromasts are generated along the entire length of the rostrum lateral line system. Accessory canals also form at regular intervals on the ventral surface of the rostrum and establish communication between the sensory canals and the external environment. This work describes the structure and growth of the rostrum lateral line system in larval and young juvenile paddlefish. Through morphological analysis of the processes of canal elongation and genesis of associated functional components, a hypothesis for dynamic rostrum lateral line canal development and growth is proposed. Because the rostrum and rostral canals form relatively late in ontogeny, and involve de novo development of significant sensory capacity, paddlefish provide a seemingly useful model for examining vertebrate sensory plasticity and integration.
