Joung et al. (1996) established that whale sharks are ovoviviparous when they reported a female (~10.6 m TL) harpooned off Taiwan (Province of China) containing approximately 300 embryos. These embryos ranged in length from 48?58 cm. One juvenile from this litter, born at 58 cm (TL), attained a length of 143 cm (TL) when raised in an aquarium for 143 days (Leu et al. 1997). Sixteen whale sharks measuring 3.1?6.3 m (TL) have previously been held in captivity at the Okinawa Expo Aquarium, Japan (Uchida et al. 2000). Growth rates of three sharks held from 458?2,056 days ranged from 21.6? 29.5 cm per annum, but may not be comparable to growth rates in the wild. There have been few reports of pregnant females or juvenile whale sharks under 3 m (TL) in the literature (Wolfson 1983). The largest female so far reported is an estimated 20 m, 34 t Whale Shark landed in Taiwan (Province of China) (Chen et al. 1997, 2002), although other sources suggest a 15 m maximum total length (TL).

No long-term studies have produced validated growth rates in the wild, age at maturity, or maximum age for this species, although Pauly (2002) has tentatively suggested a slow growth rate and a 5?6% annual mortality rate for adult R. typus and estimated longevity as 60?>100 years, for a total length of 14 m. Wintner?s (2000) study of vertebral growth rings recorded three mature males with 20, 24 and 27 growth rings at 903, 922 and 945 cm TL respectively, and an immature female with 22 rings and 577 cm TL (calculated from a precaudal length of 445 cm). The presence of scars and abrasions on the claspers of several sharks over 9 m (TL) at Ningaloo Marine Park (Norman 1999) also suggests that sexual activity, at least in males, is not common prior to attaining this length. Wintner (2000) also found that adding a theoretical data point at 100 years and 14 m TL produced a Bertalanffy growth curve with lower standard errors and Linf closer to the reported maximum length than did 60 years and 14 m TL.

The Fishbase (www.fishbase.org) default life history tool for this species is set at a maximum length of 20 m TL and, strangely, Linf of 14 m TL. This yields an estimated age at maturity of nine years at 560 cm TL, a generation time of 21 years and longevity of 59 years. Most of these parameters are clearly too low. Recalculating these data for Linf 20 m TL yields an age at maturity of 21 years at 770 m TL (still low). Generation time becomes an estimated 63 years and longevity almost 150, which seems too high for a warm water species, although recorded for some species of sturgeon Acipenseridae.

Chang et al. (1997) considers that a breeding ground for whale sharks apparently lies close to Taiwan (Province of China). However, the length of gestation, localities of birth, and frequency of reproduction are not yet known for this species and require further study.

Because of their large size, Whale Sharks are probably not subject to extensive predation after reaching maturity. There are only two reports of juvenile whale sharks taken by another animal: a Blue Marlin (A. Goorah pers. comm.) and a Blue Shark (Kukuyev 1996). Several Whale Sharks from Ningaloo Reef possess scars that may be the result of shark attack at an early age (Norman 1999) and two orcas Orcinus orca have been filmed attacking, killing and consuming an 8m whale shark (O?Sullivan and Mitchell 2000).

The Whale Shark is one of only three species of shark that filter feeds, the other two being the Megamouth (Megachasma pelagios) and Basking Shark (Cetorhinus maximus) (Compagno 1984a). Unlike these two, the Whale Shark does not rely on forward motion for filtration, but is able to hang vertically in the water and suction feed by closing its gill slits and opening its mouth (Compagno 1984a). Rhincodon typus is believed to be able to sieve zooplankton as small as 1 mm in diameter through the fine mesh of their gill-rakers (Taylor 1994), typically feeding on a variety of planktonic and nektonic prey, small crustaceans and schooling fishes and even occasionally ingesting small tuna and squid (Last and Stevens 1994, Clark and Nelson 1997, Norman 1999).