Commercial Shark Fishery Observer Program
Observer Training
|
Biological Sampling
|
The Florida Program for Shark Research is currently undertaking several shark life history and
reproductive biology studies. We are examining the life history (age and growth) of three sharks:
tiger shark (Galeocerdo cuvier);
scalloped hammerhead (Sphyrna lewini); great hammerhead (Sphyrna mokarran).
By analyzing the growth rings (patterns of calcium deposition) in shark vertebrae, we are able
to determine the age of specimens caught. Ultimately this will allow us to develop a growth curve
for the sharks in question. Accurate growth curves are essential for the proper management of shark
populations.
|
Vertebrae removal from a bonnethead shark (Sphyrna tiburo) © FLMNH
|
We are also studying the reproductive biology of five shark species: blacknose shark
(Carcharhinus acronotus); sandbar shark (C. plumbeus); tiger shark (Galeocerdo
cuvier); scalloped hammerhead (Sphyrna lewini); great hammerhead (Sphyrna mokarran).
Analyzing the reproductive condition and samples of the reproductive tract will allow researchers to
determine the reproductive characteristics, such as the reproductive cycle, for these species.
|
|
|
One of the duties of the commercial shark fishery observer is to obtain biological samples for ongoing
life history and reproductive biology projects. To this end, one day of the weeklong observer
training is dedicated for instruction in biological sampling. The training begins with a lecture
on basic life history (age and growth) and elasmobranch reproduction; covering basic reproduction,
reproductive anatomy, and an overview of the ongoing projects. The next step in the training process
is to learn to identify the requested reproductive tissue and how to dissect the sharks. Observers
are trained to identify and remove portions of the reproductive tract: in male sharks, testes,
epididymides, and seminal vesicles; in female sharks, ovaries, nidamental glands (shell glands),
and uteri. An emphasis on the proper techniques of dissection, as well as, the proper protocol for
fixing the tissue in formalin, is stressed.
|
|
To view larger images, click your mouse on each photo:
Portions of the reproductive tract from male specimens. A. testes, B. seminal vesicles © FLMNH
|
Portions of the reproductive tract from female specimens. A. nidamental glands, B. uteri © FLMNH
|
Male reproductive organs of a shark:
A. testes, B. epididymides, C. seminal vesicles © FLMNH
|
Female reproductive organs of a shark
A. ovary, B. nidamental gland, C. uterus © FLMNH
|
|
|
|
|
