Variation in the ampullae of Lorenzini, electroreceptors, of sharks from various habitats

Methods

Summary

Our team will collect biological information on the catch site, size, sex, and species of shark obtained through international shark control programs. From all specimens possible we aim to obtain biopsies of the electroreceptive sensory organs. These will be processed and examined in our Histology Facility using light, confocal, scanning and transmission electron microscopy. These results will lead to descriptive scientific articles on the differences in the structure and types of electroreceptive sensory organs.   

Challenges

The main challenge that we face is the unscheduled capture of sharks by the government shark control programs so we must be ready when the animals are captured to travel, meet with local fishermen working with these programs. We have also made arrangements and initial agreements to travel to Reunion Island, train local workers of the shark control program there on how to obtain these biopsies and records in order to maximize the opportunity of collection in Reunion.   

Pre Analysis Plan

All material obtained will be examined and histological descriptions will be written to identify similarities and variations between species of sharks. There will be a specific focus on the bull shark as this shark can be obtained from both freshwater and ocean habitats. For approximately 40 years scientists have speculated that sharks from differing water habitats will have physically unique electroreceptors, but few have been studied from the bull shark. Our team has published the description of these sensory organs from juvenile bull sharks born in freshwater river area of Australia and we propose a hypothesis that sharks native to ocean waters, specifically around small islands with little freshwater habitats for juveniles will have unique sensory organs for use with electroreception. All descriptions of shark sensory organs will be detailed in articles hopefully leading to strong scientific value of these sharks captured through the international shark control programs.