摘要:

AbstractMesoplodon peruvianus, a new species of beaked whale, is described on the basis of ten specimens which have either stranded or been captured between 11°12′S and 15°19′S latitude along the coasts of the provinces of Lima and Ica, south central Peru. This is the thirteenth living species ofMesoplodonrecognized in the world's oceans. The animals that were examined were uniformly gray above, shading to lighter gray below. This whale is the smallest species ofMesoplodon(maximum body length 3.72 m) and is characterized by its teeth, which are small (31 to 65 mm long), ovate in cross section, and positioned 2.5% to 8.4% of the mandibular length from the anterior extremity, and posterior to the mandibular symp

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00546.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe southern right whale dolphinLissodelphis peroniiis a seldom seen cetacean of southern latitudes. Off southern Africa, observations have been made predominantly in the major upwelling area off Lüderitz, Namibia, but the species has now also been seen south of the Orange River in South African waters. Sightings for the years 1980–1990 are documented and they reveal thatL. peroniioccurs off southern Africa both inshore and offshore and throughout the year. An opportunity for extended observation in January 1989 afforded the opportunity to record some interesting behavior patter

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00547.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe minisatellite DNA profiles from four captive killer whales (two adult males, a female and her calf) were compared to determine paternity between two potential fathers. One of the males was clearly excluded, while the other shared all paternal bands with the calf. The background of this technique, and its potential applications in captive breeding programs and field studies are discussed.

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00548.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe ages of 82 grey seals of known age from 1 to 10 yr were determined from growth layer groups in the cementum, readily seen in longitudinal sections 150 μm thick viewed under transmitted light. The sample of teeth was read five times in a series of blind replicates.With only one reading, an accuracy of 84% was achieved. This increased to 93% on the basis of three readings but improved only marginally to 94% when all five readings were considered. Accuracy was best in the middle range of ages (3–6 yr) which are the critical years for estimating age‐specific reproductive rates in population mo

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00549.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA method is presented for estimating age‐specific mortality based on minimal information: a model life table and an estimate of longevity. This approach uses expected patterns of mammalian survivorship to define a general model of age‐specific mortality rates. One such model life table is based on data for northern fur seals(Callorhinus ursinus)using Siler's (1979) 5‐parameter competing risk model. Alternative model life tables are based on historical data for human females and on a published model for Old World monkeys. Survival rates for a marine mammal species are then calculated by scaling these models by the longevity of that species. By using a realistic model (instead of assuming constant mortality), one can see more easily the real biological limits to population growth. The mortality estimation procedure is illustrated with examples of spotted dolphins(Stenella attenuata)and harbor porpoise(Phocoena phoc

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00550.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractCutaneous ridges are present at the surface of the skin in many odontocetes, and although often quite faint, may be observed with the naked eye. We have taken surface impressions and measured the ridges of individuals of seven odontocete species, and observed cutaneous ridges on three additional species. In the delphinids and the onePhyseterneonate studied, spatial periods of the ridges varied from 0.4 mm–1.7 mm and trough‐to‐peak heights from less rhan 10μm to about 60μm. TwoDelphinapterus(monodontids) had ridges significantly larger than thePhyseterand most delphinids, with spatial periods of 1.9–2.4 mm and heights 80–120 μm. We found the ridges distributed over much of the surface of the body, but relatively faint or absent on most of the head, the control surfaces, and the ventral region in some species. In all of the animals we observed, the ridges ran in an approximately circumferential direction around the body trunk rostral to the dorsal fin or mid‐body area, but varied somewhat in direction in the caudal region and in other isolated areas. While the function of the cutaneous ridges has not been established, we speculate that they may play some role in tactile sensing, in the hydrodynamic characteristics of an a

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00551.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractAn annual average of 163 Kuril seals was found dead in two years in salmon trap nets along the coastal waters of the Nemuro Peninsula and adjacent areas. The seal‐caused damage to the total salmon catch at the salmon trap nets was concentrated in some of them, particularly No. 27, where seals killed or injured 5.1% of the catch in 1982, and 1.8% in 1983. Based on the proportion of Kuril seals among the dead seals in the trap nets, it was estimated that Kuril seals damaged 4.7% of the total salmon catch at No. 27 in 1982, and 1.7% in 1983. Not all seals that entered the trap net drowned; some killed or damaged salmon, and then escape

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00552.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00553.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

TheComprehensiveAssessment ofWhaleStocks—TheEarlyYears. G. P. Donovan, e

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00554.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1991.tb00555.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY