By Bret Weinstein
Geographic Range
These dolphins are restricted to tropical and subtropical waters.
Biogeographic Regions:
indian ocean (native ); atlantic ocean (native ); pacific ocean (native ).
Reproduction
Breeding appears to be year-round with a possible peak in the summer months.
Breeding appears to be year-round with a possible peak in the summer months. The gestation period is thought to be about 11 months. Sexual maturity of both sexes occurs at about seven years of age. There is no sexual dimorphism except in the size and shape of the dorsal-fin, with male fins being larger than female fins.
Key reproductive features:
iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Behavior
No predation on this species has been observed, but killer whales, false killer whales and sharks probably occasionally take these dolphins as prey. Fraser's dolphins are often found with other whales, especially melon-headed whales, but also pilot whales and many other dolphin species. Groups tend to be large, ranging from 100-2500. When fleeing from ships, these dolphins can reach speeds of 28 km/h.
Key behaviors:
natatorial ; motile ; social .
Food Habits
Fraser's dolphins primarily eat fish, but they also feed on squid, cuttlefish and shrimp. There is strong evidence that these animals prefer to feed at depths of 250-500 meters and rarely at the surface.
Animal Foods:
fish; mollusks; aquatic crustaceans.
Economic Importance for Humans: Negative
Because they do not feed at the surface, they do not compete with fisherman for tuna or other pelagic fish.
Economic Importance for Humans: Positive
People in many Asian cultures hunt this species for food.
Conservation Status
CITES Appendix 2
Contributors
Bret Weinstein (author), University of Michigan.