Growth and Maximum Size of Tiger Sharks (Galeocerdo cuvier) in Hawaii

Abstract

Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13′17″N 109°52′14″W), in the southern Gulf of California (minimum distance between tag and recapture sites = approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates.

Armadillo consumption by a tiger shark: an ethnozoological contribution

“…tropical and temperate regions worldwide (Meyer et al, 2014). It is currently listed by the IUCN as Near Threatened (Simpfendorfer, 2009), and is well-known scientifically, including studies about feeding habits (Bornatowski et al, 2007(Bornatowski et al, , 2012, habitat use (Heithaus et al, 2002), movement patterns (Meyer et al, 2009), behavior (Tricas et al, 1981), and even interspecific interactions Fitzpatrick et al, 2012).…”

The biology and ecology of the tiger shark (Galeocerdo cuvier) on the east coast of Australia

“…Nevertheless, the range of biological information obtained from ~ 4700 sharks over an 18-year period has also resulted in a comprehensive review of the biology of a range of large carcharhinids from Hawaiian waters (e.g. Polovina and Lau, 1993;Lowe et al, 1996;Holland et al, 1999;Meyer et al, 2009;Meyer et al, 2010;Papastamatiou et al, 2013;Meyer et al, 2014). carcharias (between 0 -20) (Fisheries, 2006).…”

“…Species may also differ considerably between locations in terms of growth rate (Tanaka et al, 1990;Lessa et al, 2004;Harry et al, 2013;Gutteridge et al, 2013;Meyer et al, 2014), longevity (Wintner and Dudley, 2000;Allen and Wintner, 2002;Geraghty et al, 2014), size-at-maturity (Parsons, 1993;Frisk et al, 2001;Francis and Duffy, 2005;Semba et al, 2011;Montealegre-Quijano et al, 2014) and maximum size (Pratt and Casey, 1990;Cortés, 2000;Allen and Wintner, 2002;Carlson and Baremore, 2005;Neer et al, 2005;Meyer et al, 2014), which suggests that age and growth assessments may be of value in the understanding of individual populations of target species.…”

“…Maximum body size ranges from about 80 cm total length (TL) in R. taylori (Simpfendorfer, 1993;Taylor and Bennett, 2013), to around 550 cm in G. cuvier (Meyer et al, 2014).…”

“…Species may also differ considerably between locations in terms of growth rate (Tanaka et al, 1990;Lessa et al, 2004;Harry et al, 2013;Gutteridge et al, 2013;Meyer et al, 2014) Remote monitoring of geographical position, swimming depth and water temperature allows researchers to make inferences about how aquatic predators utilise their surrounding environment, providing insights into their behavioural ecology (e.g. see Holland et al, 1999;Bonfil et al, 2005;Domeier, 2006;Carlson et al, 2010;Barnett et al, 2011;Block et al, 2011;Bunnefeld et al, 2011).…”