Journals 2004/2005

Charlene Mauro
Navarre High School, Navarre Florida

"Tracking Juvenile Bull Sharks in the Indian River Lagoon" Indian River Lagoon, Florida June 28 - July 9, 2004

Journal Index: June 28 - 29 - 30 July 1 - 2 - 6 - 7 - 8 - 9

June 30, 2004

Today I prepped shark vertebrae for age and growth studies. Since sharks lack hard parts such as usable scales and otoliths, information on age and growth in sharks is derived from counts of opaque and translucent bands of vertebral centra or spines. Here's an amateur (that's me!) summary on how it is done:

1. Excess tissue is removed from the centra using a scalpel and sodium hypochlorite solution.
2. The vertebrae are cut in half sagittally or sliced at various thickness to enhance the visibility of growth bands.
3. Vertebrae are then stored in 95% isopropyl alcohol.
4. Sections can be stained with crystal violet or silver nitrate, alizariran red to enhance the growth bands.
5. Opaque and translucent bands are then counted by placing a section under a dissecting microscope interfaced with an image analysis system.

Don't be fooled, it is a very time consuming process!

The highlight of the day was making plans for our first day in the field (THURSDAY) YAHOO!