IMLAY, G.J.*; PIRTLE, T.J.; NOREKIAN, T.P.; SATTERLIE, R.A.; Arizona State University; Arizona State University; Arizona State University; Arizona State University: Neuromuscular Morphology of Buccal Cones in Clione limacina
The pteropod mollusk Clione limacina is a carnivorous predator, which feeds exclusively on actively swimming, shelled pteropods of the genus Limacina. Prey capture in Clione is achieved by rapidly extending (approximately 70 ms) three pairs of oral appendages, known as buccal cones, which surround and adhere to the outer shell of Limacina. Once prey acquisition is achieved, the buccal cones retract and manipulate the opening of the Limacina shell so that prey consumption can begin. Evidence of both rapid and fine motor movements within the buccal cones during prey capture in Clione has been well established, yet little is known how neuromuscular control of this behavior is achieved. Thus, the goal of the present investigation was to describe the neuromuscular morphology of the buccal cones, specifically including the distribution of the neuroactive peptides Myomodulin and SCPb (small cardiac peptide b). Investigative methods of immunohistological examination were utilized with both light and electron microscopy. Results indicated the presence of the neuroactive peptide Myomodulin distributed more centrally throughout the length of the buccal cones near longitudinal and circular muscle fibers. In contrast, the neuroactive peptide SCPb was distributed more peripherally throughout the length of the buccal cones, also near longitudinal and circular muscle fibers. It is concluded that neural innervation of longitudinal and circular muscles within the buccal cones in Clione may involve the neuroactive peptides Myomodulin and SCPb as neurotransmitters or neuromodulators.
