Berardius arnuxii Duvernoy 1851
Creators: name: Russell A. Mittermeier
name: Don E. Wilson
Publisher: name: Lynx Edicions
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Cetacea
Hyperoodontidae
Berardius
Berardius arnuxii

description: 2.
Arnoux’s Beaked Whale
Berardius arnuxii
French: Baleine-a-bec dArnoux / German: Arnoux-Schnabelwal / Spanish: Zifio de Arnoux
Other common names: New Zealand Beaked Whale, Southern Fourtoothed Whale
Taxonomy. Berardius arnuxi Duvernoy, 1851,
“échoué sur la cote, dans le port d’Akaroa, presqu’ile de Bancks, dans la Nouvelle-Zélande” (= New Zealand, Canterbury Prov., Akaroa).
This species is monotypic.
Distribution. Subantarctic and Antarctic waters from Antarctica to South Africa, S Australia, N New Zealand, and South America.
Descriptive notes. Total length 800- 930 cm; weight ¢.9000 kg. There is no clear evidence of sexual dimorphism in body size of Arnoux’s Beaked Whale. Its bodyis 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 ofthe tail. Coloration is typically dark brown, dark gray, or black. Bodies of some individuals, especially older ones, can be covered in white linear scars from intraspecific aggression or pale oval scars from attacks by cookie-cutter sharks (/sistius spp.). Rostrum and lowerjaw form a moderately long beak that is clearly distinct from the melon. Adults have two pairs oftusks set in the lowerjaw; front pair is larger. Unlike many other species of beaked whales, tusks erupt in adults to become functional in both males and females. Tusks of Arnoux’s Beaked Whales can become heavily worn in older individuals.
Habitat. There is no specific information available for this species, but like all species of beaked whales, Arnoux’s Beaked Whaleis restricted to deeper oceanic waters.
Food and Feeding. Little is known about the diet of Arnoux’s Beaked Whale, but they are known to consume deep-water squid and possibly deep-water fish. In common with otherspecies of beaked whales, feeding is likely to occur at great depth, often greater than 500 m and possibly as deep as 3000 m or more. Foraging dives may be up to an hour in length, and prey capture is likely to be by suction feeding.
Breeding. There is no specific information available for this species, but based on information from the related Baird’s Beaked Whale (B. baurdii), individuals are likely to become sexually mature at ¢.10 years of age and physically mature at ¢.20 years. Some individuals may live as long as 80 years.
Activity patterns. There is no specific information available for this species, but if, as is the case in other beaked whales, it consumes relatively small prey, individual Arnoux’s Beaked Whales likely spend a large proportion (60-70%) of their time foraging at great depths.
Movements, Home range and Social organization. There is no specific information available for this species, but as with the related Baird's Beaked Whale, Arnoux’s Beaked Whale seems to occur in larger groups than most species of beaked whales, and there may be as many as 80 individuals in the largest groups. Groups are likely to contain multiple adult males and females, as well as dependent offspring. Nothing is known about possible substructuring within these groups.
Status and Conservation. CITES Appendix I. Classified as Data Deficient on The [IUCN Red List. There are no estimates of global population size of Arnoux’s Beaked Whales. [t appears to be uncommon throughoutits distribution, and it is considered by some to be naturally rare. Arnoux’s Beaked Whale is likely to be affected by the same factors that affect other species of beaked whales, including noise pollution, overfishing of deep-water ecosystems, and ingestion of plastic debris. As a species restricted to cooler water, Arnoux’s Beaked Whales may also be at risk from effects of climate change. Nevertheless, nothing is known about the form or extent of these potential impacts.
Bibliography. Balcomb (1989), Macleod (2006), MacLeod & D'Amico (2006), MacLeod et al. (2006), Rice (1998).
description: Published as part of Russell A. Mittermeier & Don E. Wilson, 2014, Ziphiidae, pp. 326-357 in Handbook of the Mammals of the World – Volume 4 Sea Mammals, Barcelona :Lynx Edicions on page 347, DOI: 10.5281/zenodo.6608481