Mesoplodon peruvianus, Reyes, Mead & Van Waerebeek, 1991

Russell A. Mittermeier & Don E. Wilson, 2014, Ziphiidae, Handbook of the Mammals of the World – Volume 4 Sea Mammals, Barcelona: Lynx Edicions, pp. 326-357 : 352

10.

Pygmy Beaked Whale

Mesoplodon peruvianus

French: Baleine-a-bec du Pérou / German: Zwergzweizahnwal / Spanish: Zifio del Peru

Other common names: Lesser Beaked Whale, Mesoplodon species A, Peruvian Beaked Whale

Taxonomy. Mesoplodon peruvianus Reyes, Mead & Van Waerebeek, 1991 ,

“Playa Paraiso (11° 12’ S), Huacho, Lima, Peru.”

This species was formerly known as “ Mesoplodon species A ” based on sightings of a then unknown species of beaked whale. Monotypic.

Distribution. E tropical Pacific from 28° N to 29° S. A single record from New Zealand is currently thought to represent a vagrant individual, but it may be that the distribution of this species is wider than initially thought.

Descriptive notes. Total length 370-390 cm; weight ¢.500 kg (unconfirmed). Body of the Pygmy Beaked 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. Females and juvenile Pygmy Beaked Whales are dark on top and paler underneath. Adult males have a distinct white chevron on their backs. Adult males may have a number of long white lines that are unpigmented scars from aggressive male-male interactions. Rostrum and lower jaw form a short but distinct beak, and there are two grooves on the throat. Lower jaw of adult males is arched, and a small pair of tusks is found midway along it.

Habitat. All confirmed sightings from deep, oceanic waters, and it is presumed that this reflects habitat preferences of the Pygmy Beaked Whale.

Food and Feeding. The Pygmy Beaked Whale is thought to primarily consume deepwater fish, but this is based on a very small sample. It also may consume deep-water squid. As with other species of beaked whales, the Pygmy Beaked Whale is likely to forage 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 specific information available for this species, but it is known to occur in small groups of five or fewer individuals. Typical composition of these groups remains unclear.

Status and Conservation. CITES Appendix II. Classified as Data Deficient on The [UCN Red List. There are no estimates of global population size of the Pygmy Beaked Whale. It may be one of the more common species of Mesoplodon in some parts of its distribution. Like other species of beaked whales,it is potentially affected by ingestion of plastic debris, bycatch in driftnet fisheries, and noise pollution. Nevertheless, nothing is known about the form or extent of these potential impacts.

Bibliography. Macleod et al. (2006), Pitman & Lynn (2001), Reyes et al. (1991).

Figures

1. Baird’s Beaked Whale (Berardius baiwrdu), 2. Arnoux’s Beaked Whale (Berardius arnuxu), 3. Cuvier’s Beaked Whale (Ziphius cavirostris), 4. Northern Bottlenose Whale (Hyperoodon ampullatus), 5. Southern Bottlenose Whale (Hyperoodon planifrons), 6. Shepherd’s Beaked Whale (Tasmacetus shepherd), 7. Longman’s Beaked Whale (Indopacetus pacificus), 8. Hubbs’s Beaked Whale (Mesoplodon carlhubbsi), 9. Stejneger’s Beaked Whale (Mesoplodon stejnegeri), 10. Pygmy Beaked Whale (Mesoplodon peruvianus), 11. Perrin’s Beaked Whale (Mesoplodon perrini), 12. True’s Beaked Whale (Mesoplodon marus), 13. Strap-toothed Whale (Mesoplodon layardii), 14. Hector’s Beaked Whale (Mesoplodon hectori)

Distribution. E tropical Pacific from 28° N to 29° S. A single record from New Zealand is currently thought to represent a vagrant individual, but it may be that the distribution of this species is wider than initially thought.