Sexing beluga whales (Delphinapterus leucas) by means of DNA markers

Few methods are available for determining the sex of free-ranging individual whales, dolphins, and porpoises of species that are not obviously sexually dimorphic. We have developed a technique for sexing beluga whales (Delphinapterus leucas) by using a Y-chromosome-specific DNA restriction fragment. Genomic DNA was extracted from liver samples of 18 beluga whales (9 males, 9 females) sexed at dissection. DNA from males and females was digested with five restriction enzymes, electrophoresed, and transferred to membranes by Southern blotting. When probed with the labelled human Y-chromosome zinc finger protein gene probe pDP1007, male-specific bands and bands common to both sexes, but more intense in females than in males, were observed. The DNA digested with EcoRI provided the clearest sex-discriminating banding pattern. Even when DNA of various qualities digested with EcoRI was used, all the males showed a 3.4-kilobase (kb) band, presumably from the Y-chromosome, as well as a 2.1-kb band. Females showed the 2.1-kb band, but all lacked the 3.4-kb band. This 3.4-kb EcoRI male-specific band permits unambiguous sex determination, which will facilitate examination of sex-related differences in population structure and habitat use of belugas, which have important implications for management decisions.

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Vertical sonar beam width and scanning behavior of wild belugas (Delphinapterus leucas) in West Greenland

PLoS ONE ◽

10.1371/journal.pone.0257054 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0257054

Author(s):

Marie J. Zahn ◽

Kristin L. Laidre ◽

Peter Stilz ◽

Marianne H. Rasmussen ◽

Jens C. Koblitz

Keyword(s):

Beam Width ◽

The Arctic ◽

Delphinapterus Leucas ◽

Recording Equipment ◽

West Greenland ◽

Beluga Whales ◽

Pack Ice ◽

Scanning Behavior ◽

Hydrophone Array ◽

Free Ranging

Echolocation signals of wild beluga whales (Delphinapterus leucas) were recorded in 2013 using a vertical, linear 16-hydrophone array at two locations in the pack ice of Baffin Bay, West Greenland. Individual whales were localized for 4:42 minutes of 1:04 hours of recordings. Clicks centered on the recording equipment (i.e. on-axis clicks) were isolated to calculate sonar parameters. We report the first sonar beam estimate of in situ recordings of wild belugas with an average -3 dB asymmetrical vertical beam width of 5.4°, showing a wider ventral beam. This narrow beam width is consistent with estimates from captive belugas; however, our results indicate that beluga sonar beams may not be symmetrical and may differ in wild and captive contexts. The mean apparent source level for on-axis clicks was 212 dB pp re 1 μPa and whales were shown to vertically scan the array from 120 meters distance. Our findings support the hypothesis that highly directional sonar beams and high source levels are an evolutionary adaptation for Arctic odontocetes to reduce unwanted surface echoes from sea ice (i.e., acoustic clutter) and effectively navigate through leads in the pack ice (e.g., find breathing holes). These results provide the first baseline beluga sonar metrics from free-ranging animals using a hydrophone array and are important for acoustic programs throughout the Arctic, particularly for acoustic classification between belugas and narwhals (Monodon monoceros).

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PCBs and organochlorine pesticides in blubber biopsies from free-ranging St. Lawrence River Estuary beluga whales (Delphinapterus leucas), 1994–1998

Environmental Pollution ◽

10.1016/s0269-7491(02)00288-9 ◽

2003 ◽

Vol 122 (2) ◽

pp. 291-302 ◽

Cited By ~ 38

Author(s):

Karen E Hobbs ◽

Derek C.G Muir ◽

Robert Michaud ◽

Pierre Béland ◽

Robert J Letcher ◽

...

Keyword(s):

Organochlorine Pesticides ◽

River Estuary ◽

Delphinapterus Leucas ◽

Beluga Whales ◽

Free Ranging ◽

St Lawrence River

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Cloning and comparative analysis of zinc-finger protein gene on Y-chromosome ( ZFY ) between Thai Bangkaew dog and other Thai canids

Agriculture and Natural Resources ◽

10.1016/j.anres.2016.12.007 ◽

2017 ◽

Vol 51 (3) ◽

pp. 212-217

Author(s):

Ukadej Boonyaprakob ◽

Sommai Homsavart ◽

Jatuporn Noosud ◽

Rongdej Tungtrakanpoung

Keyword(s):

Comparative Analysis ◽

Y Chromosome ◽

Zinc Finger ◽

Protein Gene ◽

Zinc Finger Protein ◽

Zinc Finger Protein Gene ◽

Finger Protein

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Deep Diving in Wild, Free-Ranging Beluga Whales, Delphinapterus leucas

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f92-055 ◽

1992 ◽

Vol 49 (3) ◽

pp. 462-466 ◽

Cited By ~ 40

Author(s):

A. R. Martin ◽

T. G. Smith

Keyword(s):

Upper Bound ◽

Ambient Pressure ◽

High Arctic ◽

Delphinapterus Leucas ◽

Canadian High Arctic ◽

Near Surface ◽

Beluga Whales ◽

Deep Diving ◽

Radio Transmitters ◽

Free Ranging

Three adult female beluga whales, Delphinapterus leucas, were captured during summer in the Canadian high Arctic and equipped with satellite-linked radio transmitters that measured and recorded ambient pressure every 20 s. Diving behaviour was divisible into three distinct categories: (1) near-surface, (2) "spike" dives to 20–150 m depth, and (3) prolonged, flat-bottomed dives to a maximum depth of 350 m. The duration of these prolonged dives was 9.3–13.7 min, but the upper bound is known to be underestimated. Average descent rates varied between dives in the range 1.43–2.20 m/s and ascent rates between 1.23 and 1.84 m/s. Within periods of 20 s duration, maximum descent and ascent rates were 2.55 and 2.35 m/s, respectively. After most prolonged dives the rate of ascent declined progressively as the surface was approached, particularly in the final 100 m. Such dives were usually to, or near to, the seabed and were probably for foraging. Up to 42% of an animal's time could be spent at depths of 8 m or more.

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