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White Patch on the Fore-Flipper of Common Minke Whale, as a Potential Morphological Index to Identify Stocks

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DOI: 10.4236/ojas.2016.62014    1,281 Downloads   1,483 Views  

ABSTRACT

Past studies have indicated that there are two different stocks (J and O stocks) in the North Pacific common minke whale Balaenoptera acutorostrata population. These two stocks differ from each other in certain characteristics, such as body size, conception dates, and genetics. However, till date, few studies have investigated differences in the external body appearance between the two stocks. Therefore, in the present study, we focused on the unique white patch on the flipper of this whale species to elucidate inter-stock differences. We used the animals collected from JARPNII research during 2012 and 2013; stock information was determined by microsatellite DNA analysis (n = 220). We focused on the morphological differences in the size and pattern of the white patch on the flipper of each whale. The length of the white patch along the anterior (ventral) margin of the flipper tends to be proportionally larger in O stock. The pattern of the boundary area of the white patch named as the “Grayish Accessary Layer (GAL)” was remarkably different between stocks. Within animals with “no GAL” type, 94% were J stock. Conversely, of animals with GAL expanding over the half the flipper width, 96% were O stock. We concluded from our study that there were clear morphological differences in the flipper color pattern between J and O stocks, which enable to apply widely to other individuals.

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Nakamura, G. , Kadowaki, I. , Nagatsuka, S. , Hayashi, R. , Kanda, N. , Goto, M. , Pastene, L. and Kato, H. (2016) White Patch on the Fore-Flipper of Common Minke Whale, as a Potential Morphological Index to Identify Stocks. Open Journal of Animal Sciences, 6, 116-122. doi: 10.4236/ojas.2016.62014.

References

[1] Rice, D.W. (1998) Marine Mammals of the World. Systematics and Distribution, Society for Marine Mammalogy Special Publication 4.
[2] Kato, H. and Fujise, Y. (2000) Dwarf Minke Whales; Morphology, Growth and Life History with Some Analyses on Morphometric Variation among the Different Forms and Regions. Paper SC/52/OS3 Presented to the Scientific Committee, June 2000, 30 p. (Unpublished)
[3] Nakamura, G., Kadowaki, I., Nagatsuka, S., Fujise, Y., Kishiro, T. and Kato, H. (2014) Variation in a Color Pattern of White Patch on the Flippers of North Pacific Common Minke Whales: Potential Application for Their Interoceanic Difference. La Mer, 52, 31-47.
[4] Ohsumi, S. (1983) Minke Whales in the Coastal Waters of Japan in 1981, with Special Reference to Their Stock Boundary. Reports of the International Whaling Commission, 33, 365-371.
[5] Ohsumi, S. (1977) Minke Whales in the Coastal Waters of Japan. Reports of the International Whaling Commission, 27, 164-166.
[6] Hatanaka, H. and Miyashita, T. (1997) On the Feeding Migration of Okhotsk Sea. West Pacific Stock of Minke Whales, Estimates Based on Length Composition Data. Reports of the International Whaling Commission, 47, 557-564.
[7] Wada, S. (1991) Genetic Structure of Okhotsk Sea—West Pacific Stock of Minke Whales. Paper SC/43/Mi32 Presented to the IWC Scientific Committee, May 1991, 17 p. (Unpublished)
[8] Goto, M. and Pastene, L.A. (1997) Population Structure of Western North Pacific Minke Whale Based on an RFLP Analysis of MtDNA Control Region. Reports of the International Whaling Commission, 47, 531-537.
[9] Kanda, N., Goto, M., Kishiro, T., Yoshida, H., Kato, H. and Pastene, L.A. (2009) Individual Identification and Mixing of the J and O Stocks around Japanese Waters Examined by Microsatellite Analysis. Paper SC/J09/JR26 Presented to the JARPN II Review Workshop, Tokyo, January 2009, 9 p. (Unpublished)
[10] Kato, H. (1992) Body Length, Reproduction and Stock Separation of Minke Whales off Northern Japan. Reports of the International Whaling Commission, 42, 443-453.
[11] Bando, T., Kanda, N., Pastene, L.A., Kishiro, T., Yoshida, H. and Hatanaka, H. (2010) An Analysis of Cookie Cutter Shark-Induced Body Scar Marks of Common Minke Whales Sampled by JARPNII in the Context of Stock Structure Hypotheses. Paper SC/D10/NPM6 Presented to the First Intersessional Workshop of Western North Pacific Minke whale Implementation, December 2010, 5 p. (Unpublished)
[12] Hakamada, T. and Bando, T. (2009) Morphometric Analysis on Stock Structure in the Western North Pacific Common Minke Whales (Balaenoptera acutorostrata). Paper SC/J09/JR27. Presented to the JARPN II Review Workshop, Tokyo, January 2009, 13 p. (Unpublished)
[13] Kanda, N., Goto, M., Nagatsuka, S., Kato, H., Pastene, L.A. and Hatanaka, H. (2010) Analysis of Genetic and Non-Genetic Data Do Not Support the Hypothesis of an Intermediate Stock in Sub-Area 7. SC/D10/NPM8 Presented to the First Intersessional Workshop of Western North Pacific Minke Whale Implementation, December 2010, 8 p. (Unpublished)
[14] Nagatsuka, S. (2010) External Morphological Difference of the Common Minke Whale (Balaenoptera acutorostrata) in the Western North Pacific. Master’s Thesis, Tokyo University of Marine Science and Technology, Tokyo. (In Japanese)

  
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