Additional projects:
1) Roi's position in the reef foodweb and it's relation to ciguatoxin concentration and distribution,
by Natalie Wallsgrove, Ph.D. Student.
To gain a better understanding of ciguatoxin (CTX) and help avoid ciguatera fish poisoning, it is important that we understand the patterns of ciguatoxin distribution, concentrations, and biological-magnification within the food web of the near shore reef ecosystem. We will be using the nitrogen in the amino acids of the fish muscle tissue as an indicator of the animal's position in the food web. The amino acids (the building blocks for protein and therefore muscle tissue) will be isolated from the muscle tissue and the nitrogen in the amino acids will be analyzed. This nitrogen analysis allows us to assign each fish sample a relative place in the food web, and we can compare these results with the results of the CTX analyses. This information can perhaps help us to understand how an individual fish may accquire ciguatoxin and how humans may avoid catching and eating affected fish.
2) Genetic diversity of roi, ta'ape, and to'au, by Michelle Gaither, Ph.D. Student.
I am a Ph. D. candidate at the University of Hawaii. For my dissertation research I am working on the genetics of the introduced fishes ta'ape (Blue Stripped Snapper, Lutjanus kasmira) to'au (Black Tail Snapper, Lutjanus fulvus), and roi (Peacock Grouper, Cephalopholis argus). These three species were introduced to Haswaii during the 1950's by the Hawaii Division of Fish and Game in an effort to enhance local fisheries. Unfortuately, none of these have become popoular game fishes and instead are regarded as pest species by local fishermen. Roi is known to cause ciguatera poisoning in Hawaii. For my work, I am collecting tissue samples from all three species throughout Hawaii. DNA is extracted from each tissue sample and analyzed in our laboratory at the Hawaii Institute of Marine Biology. The data we collect is used to gain a better understanding of how these fish spread in Hawaii (did they spread from the initial site of introduction in large or small numbers) and the impact of the number of fish introduced to Hawaii on the genetic diversity. Additionally, our lab is working on an intestinal parasite (nematode) that is thought to have been introduced to Hawaii along with ta'ape. We are using genetic tools to confirm the origin (either native or introduced) of this parasite which is known to infect six species of native Hwaiian fishes.
Our work relies upon the generous cooperation of fishermen throughout the main Hawaiian Islands who supply the majority of the whole ta'ape and to'au we need for our work. If you are interested in participating please contact me at the email below.
Michelle Gaither
email: gaither@hawaii.edu
work phone: 808-236-7471