Mesoplodon travers Gervais 1850

21.

Spade-toothed Whale

Mesoplodon travers

French: Baleine-a-bec de Travers / German: Travers-Zweizahnwal / Spanish: Zifio de Travers

Other common names: Bahamondi's Beaked Whale, Spade-toothed Beaked Whale, Traver’s Beaked Whale

Taxonomy. Dolichodon traversii Gray, 1874,

Chatham Island, New Zealand.

This species 1s monotypic.

Distribution. Currently known from three sets of cranial remains found in New Zealand, Chatham, and Juan Fernandez Is and a single stranding consisting of an adult female and ajuvenile male found in New Zealand. It is not known how these records reflect the actual distribution of this species.

Descriptive notes. Total length ¢.500-550 cm (based on a single adult female); no specific data are available for body weight. In common with other species of Mesoplodon, body of the Spade-toothed Whale is spindle-shaped, with greatest girth around its midpoint. Flukes are wide in relation to body length, and tailstock is compressed laterally. Dorsal fin is small and set approximately two-thirds the distance between tip of the beak and end of the tail. Coloration of the two known individuals was dark on top, with a white belly, dark flippers, and dark rostrum. In adult males,a single pair of tusksis set in the middle of the lowerjaw.

Habitat. There is no information available for this species.

Food and Feeding. There is no specific information available for this species, but as with other species of Mesoplodon, the Spade-toothed Whale likely eats deep-water squid and deep-water fish. Like other species of beaked whales,it likely forages at depths greater than 500 m for much ofits life.

Breeding. There is no information available for this species.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. CITES Appendix II. Classified as Data Deficient on The[IUCN Red List. There are no estimates of global population size of the Spade-toothed Whale. Like other species of beaked whales, the Spade-toothed Whale could be affected by ingestion of plastic debris and noise pollution, or caught as bycatch in driftnet fisheries. As a species that is apparently restricted to cooler waters, it may also be vulnerable to effects of climate change. Nevertheless, nothing is known about the form or extent of these potential impacts.

Bibliography. van Helden et al. (2002), MacLeod et al. (2006), Reyes et al. (1995), Thompson et al. (2012).