A Whale of a New Species

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Publications, Agencies and Staff of the U.S. Department of Commerce U.S. Department of Commerce 4-18-1991 A whale of a new species Katherine Ralls Robert L. Brownell Jr. NOAA, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/usdeptcommercepub Part of the Environmental Sciences Commons Ralls, Katherine and Brownell, Robert L. Jr., "A whale of a new species" (1991). Publications, Agencies and Staff of the U.S. Department of Commerce. 122. https://digitalcommons.unl.edu/usdeptcommercepub/122 This Article is brought to you for free and open access by the U.S. Department of Commerce at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Publications, Agencies and Staff of the U.S. Department of Commerce by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. NEWS AND VIEWS and perhaps seven, of them were captured incidentally in drift gill-nets set for sharks, and three were washed ashore. Some new specimens from the Mexican coast may also belong to this species and its latitudinal range may extend beyond the places where both the known and the suspected specimenswere collected. The teeth of the adult males are relatively small compared to those of its con- geners. The long axis of each tooth is almost ZOOLOGY perpendicular to the long axis of the man- dible (see figure), a feature which distin- guishes this species from all others in the A whale of a new species genus. Mesoplodon peruvianus is the smallest known member of the genus, and, in- Katherine Ralls and Robert L. Brownell, Jr deed, of all the beaked whales, both in terms of total length at birth (159 cm) and the ALTHOUGHfour new species of whale have appearance of the whole animal remains maximum known total adult body length of been identified since 1937, the absence of a matter of conjecture. 372 cm. (The smallest previously known new ones for the past 28 years might be taken Members of four of the five beaked whale species of Mesoplodon is M. hectori, for to mean that they had finally all been dis- genera have reduced numbers of teeth. The which the smallest calf measured 190 cm in covered. Not so - a new species of beaked name Mesoplodon (loosely interpreted as length and the maximum known adult total whale, Mesoplodonperuvianus, is described "armed with a tooth in the middle of the length is 443 cm.) by J. C. Reyes and colleagues in the latest jaw") refers to the two remain- issue of Marine Mammal Science'. ing functional teeth of adult The beaked whales, family Ziphiidae, males, which are on the lower comprise almost 30 per cent of the toothed jaw and are one of their most whales but are poorly known. In contrast, the striking features. The bizarre great baleen whales are well described, teeth of the male strap-toothed in part because they were commercially whale (M. layardii) even grow hunted, and no new species have been dis- up and over the upper jaw, covered since 1878, when the last of the ten sometimes actually touching now recognized, Bryde's whale, was named2. and thus preventing their Six of the seven beaked whales described in owner from opening his mouth this century are in the genus Mesoplodon more than about five cm (ref. (see table), and most of what little is 3). The amount of the tooth ex- known about the genus, and the family as a posed in the living animal to species: Dorsal view of the lower jaw of the holotype of Mesoplodon whole, has been gleaned from carcasses varies washed ashore. One species (M. pacificus) peruvianusl. That only two teeth remain functional is in some the tooth is characteristic of males of the genus; that their long axis is is still known only from its bones and the whereas in almost. .. ... oeroendicularr- ,-~ to the jaw is characteristic of the of it is covered gum species. Length of the jaw is about 53 cm. Species of cetacean described since 1900 tissue and only the tip pro- (refs 1,2)* trudes. Females also have the same two teeth There have been several sightings of a distinctive but unidentifiable species of Andrews' beaked whale. Mesoplodon bow- in the lower jaw, but they are not functional donini Andrews. 1908 as they rarely emerge from the gums. The beaked whale in the eastern tropical Pacific, Spectacled porpoise, Australophocaena dio- meagre data available imply that these ani- meaning that there still may be at least one ptrica (Lahille, 1912) mals prey predominantly on squid and fish more undescribed species of Mesoplodod. True's beaked whale, M. rnirus True, 1913 found at moderate to considerable depths3,a Given that Earth's dwindling large-mammal Baiji (Chinese river dolphin), Lipotes vexillifer soft diet that can be captured and consumed fauna is comparatively well catalogued, Miller, 1918 without the aid of teeth. Mesoplodon is likely to remain the least Longman's beaked whale, M. pacificus Long- In Mesoplodon, linear scars up to about 2 known genus of large mammal - as Mina- man, 1926 m in length are often found on adult males, sian and colleagues have pointed out in The Tasman beaked whale, Tasmacetus shep- World's Whales6, "The mysteries these herdi Oliver, 1937 and are usually assumed to be the result of in- Fraser's dolphin, Lagenodelphis hosei traspecific combat. These scars often occur strange whales present will not be easily Fraser, 1956 as pairs of parallel lines, implying that they solved by the handful of specimens chance Vaquita (Gulf of California harbour porpoise), were formed by the two teeth of a rival provides in one lifetime". Phocoena sinus Norris and McFarland, male3'4; males keep the mouth Katherine Ralls is at the National Zoological 1958 'lased while wounding other males. Mem- Park, Smithsonian Institution, Washington, Ginkgo-toothed beaked whale, M. hers of the genus tend to occur as anti- DC20008, USA. Robert L. Brownell, Jr, is with ginkgodens Nishiwaki and Kamiya, 1958 tropical pairs of closely related species, a the US fish and Wildlife Service, San Simeon, Hubbs' beaked whale, M. carlhubbsi Moore, California 93452, USA. 1963 species of each pair occurring in the tem- M. peruvianust, Reyes et al., 1991 perate waters of each of the two hemis- pheres, although One (M. densirostris) is 1. Reyes. J. C.. Mead, J. G. &Van Waerebeek. K. V. Marine *All I1species are toothed whales, seven are and two Mammal Scr. 7, 1 (1991). found in tropical waters 2. Honackl, J. H. eta/. Mammal Spenes of the World - A beaked whales (family Ziphiidae), and six of others (M.ninknodens and M. DUC~~~CUS)T~xonomic and Geopraphrc Reference (~11~"presc \ "V these seven are in the genus Mesoplodon. Lawrence. Kansas. 1982). are confined to the waterr the 3. Mead, J. G. Handbook of Manne Mammals Vol. 4, 34, The genus Tasmacetus also belongs to the Pacific and Indian Oceans. / beaked whales. (Academic. New York. 1989). The latest example of Mesoplodonwasde- 4. Heyning. J. E. Cand. J. Zool. 62. 1645 (1984). 'As Reyes etal. provide no common name for 5. Pitman. R. L. etal. Manne MammalSci. 3. 345 (1987). the newly described species, we propose the scribed from ten specimens collected from 6. Minaslan. S. M. et al. The World's Whales (Smithsonlan name pygmy beaked whale. the central and southern Peruvian coast. Six, Books. Washlngton.DC. 1984). 560 NATURE - VOL 350 - 18APRIL 1991 .

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