Dose the Lateral Bundle of the Medial Olfactory Trace Mediate Reproductive Behavior in Male Crucian Carp?

摘要

The olfactory tract in crucian carp (Carassius carassius) is divided into three distinct bundles: the lateral tract (LOT) and the laternal (IMOT) and medial (mMOT) bundles of the medial tract. The LOT has been shown to mediate information associated with feeding behavior, whereas the mMOT mediates information associated with alarm response. The role of the medial olfactory tract (IMOT and mMOT) in reproductive behavior is still under debate. In the present experiment, male reproductive behavior towards prostaglandin-injection females was investigated before and after cutting off the different olfactory trace bundles, to determine which of the trace bundles is essential for mediating reproductive behavior in male crucian carp. The fish were maintained in physiological saline before and after surgery to preserve the reamaining trace bundles. Operations were performed symmetrically on both sides and post-operative inspections revealed the functionality of the intact tracts. Sham-operated males and males with only the IMOT intact showed typical reproductive behavior, with following of the female and inspections of the female anal papilla. However, males in which the IMOT was cut, leaving both the mMOT and the LOT intact, showed reduced reproductive behavior. Our results suggest that the IMOT mediates reproductive behavior in male crucian carp.