Aging Florida’s Horse Conch (Triplofuses giganteus) Using Isotope Sclerochronolgy, Morphology and Laser Ablation (LA-ICP-MS)
Mentor Information
Gregory Herbert (School of Geosciences)
Description
The Horse Conch (Triplofusus giganteus) is heavily sought-after by collectors and harvested by commercial fisheries with little or no regulation and oversight and, thus, high risk of overexploitation. Management of Horse Conch populations should ideally consider how rapidly harvested individuals can be replaced by reproduction, a rate determined by life history traits (e.g., lifetime fecundity, age at reproductive maturation). In this presentation, we summarize oxygen isotope sclerochronology-based estimates of Horse Conch age and refine them with new data from Laser Ablation (LA-ICP-MS). Geochemistry-based age estimates are also used to test whether years of growth can be reliably and more rapidly assessed with morphology (e.g., growth lines on the operculum and growth breaks on the shell). Fish and Wildlife researchers conjectured that this species may live up to 80 years based on other molluscan growth rates. Our preliminary data suggest that Horse Conchs usually live at most around 15 years. Thus, recovery time for populations of this species being harvested is still slow, but more rapid than initially hypothesized.
Aging Florida’s Horse Conch (Triplofuses giganteus) Using Isotope Sclerochronolgy, Morphology and Laser Ablation (LA-ICP-MS)
The Horse Conch (Triplofusus giganteus) is heavily sought-after by collectors and harvested by commercial fisheries with little or no regulation and oversight and, thus, high risk of overexploitation. Management of Horse Conch populations should ideally consider how rapidly harvested individuals can be replaced by reproduction, a rate determined by life history traits (e.g., lifetime fecundity, age at reproductive maturation). In this presentation, we summarize oxygen isotope sclerochronology-based estimates of Horse Conch age and refine them with new data from Laser Ablation (LA-ICP-MS). Geochemistry-based age estimates are also used to test whether years of growth can be reliably and more rapidly assessed with morphology (e.g., growth lines on the operculum and growth breaks on the shell). Fish and Wildlife researchers conjectured that this species may live up to 80 years based on other molluscan growth rates. Our preliminary data suggest that Horse Conchs usually live at most around 15 years. Thus, recovery time for populations of this species being harvested is still slow, but more rapid than initially hypothesized.
