Chinese Journal of Zoology 2010 45 2 143 ~ 150 1 1 2 2 2 1 1* 1 510275 2 519001 14 9 5 Sousa chinensis 69 Q951 A 0250-3263 2010 02-143-08 Sexual Dimorphism in External Morphology Skull Scapula and Fin Bones of Sousa chinensis Died in the Pearl River Estuary ZHAI Kan 1 ZHANG Hai-Fei 1 CHEN Jia-Lin 2 CHEN Xi 2 XU Guang-Ting 2 NING Xi 1 WU Yu-Ping 1 * 1 School of Life Sciences Sun Yat-sen University Guangzhou 2 Pearl River Estuary Chinese White Dolphin National Nature Reserve Zhuhai 510275 519001 China Abstract Characteristics of appearance skull scapula and fin bones morphology were described by 69 measurements taken from 14 specimens Sousa chinensis dead in the Pearl River Estuary. Those measurements were analyzed by one-way ANOVA to reveal the sexual dimorphism between individuals from different geographic locations. No difference was found in external measurements between male and female but significant difference was detected in partial measurements on skull scapula and fin bones between male and female. In general the mean values of most measurements were larger in female than those in male. Key words Sousa chinensis External morphology Skull Scapula and fin bones Sexual dimorphism Sousa chinensis S. teuszii Chordata Mammalia Cetacea Odontoceti Delphinidae 1988 Ⅰ No. 30570255 30870313 40976082 * E-mail exwyp@ 163. com Ⅰ 1 E-mail kan1112@ 126. com 2009-09-01 2009-12-21
144 Chinese Journal of Zoology 45 S. plumbea 1 S. chinensis 3 1870 Flower 2 1. 1 Porter 3-4 14 5 9 / Jefferson 18 5 200 cm 190 1. 2 6 3 6-9 5 5 4 10-13 1982 14 1996 15 1 60 mm 3 /4 / 16 1 000 17
2 145 Fig. 1 1 The skeleton of Sousa chinensis Jefferson 18 200 cm 190 SPSS 13. 0 2 14 4 1 4 18 Ross 19 P = 0. 062 P = 0. 056 P = 0. 056 P 0. 05 1 60 mm Jefferson 18 n = 5 230 ~ 269 cm 257. 3 6. 4% n = 9 190 2 ~ 270 cm 891. 25 13. 1% 3 190 cm 3 190 cm Jefferson 14 2
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2 149 Table 3 3 Summary of scapula and fin bones morphology measurements on female and male cm Variable n Mean value Female individuals Range n Variance CV % Mean value Male individuals Range * Sexual dimorphism Variance CV % 15. 7 ± 1. 4 5 13. 5 ~ 17. 2 1. 84 8. 66 13. 8 ± 2. 3 9 11. 1 ~ 16. 6 5. 26 16. 59 Height of scapula 22. 4 ± 2. 0 5 19. 0 ~ 23. 9 3. 84 8. 75 19. 9 ± 2. 7 9 16. 1 ~ 24. 1 7. 49 13. 77 Width of scapula 5. 8 ± 1. 5 5 4. 3 ~ 7. 4 2. 11 25. 00 5. 9 ± 1. 7 8 3. 4 ~ 8. 4 2. 97 29. 15 Length of superior border of acromion 7. 5 ± 2. 4 5 5. 1 ~ 10. 9 5. 96 32. 53 6. 6 ± 2. 3 8 3. 6 ~ 10. 6 5. 14 34. 39 Length of inferior border of acromion 4. 2 ± 1. 2 5 2. 7 ~ 5. 8 1. 48 29. 05 3. 4 ± 0. 8 8 2. 2 ~ 4. 5 0. 59 22. 65 Width of acromion distally 3. 5 ± 0. 7 5 2. 7 ~ 4. 6 0. 53 20. 86 2. 7 ± 1. 0 8 1. 6 ~ 4. 8 1. 04 37. 41 Length of superior border of coracoid process 3. 6 ± 0. 7 5 2. 7 ~ 4. 7 0. 56 20. 56 2. 7 ± 1. 0 8 1. 8 ~ 4. 9 0. 99 37. 04 Length of inferior border of coracoid process 1. 8 ± 0. 4 5 1. 2 ~ 2. 1 0. 13 19. 44 1. 3 ± 0. 3 8 1. 0 ~ 1. 9 0. 09 23. 08 0. 031 Width of coracoid process distally 3. 7 ± 0. 3 5 3. 4 ~ 4. 1 0. 08 7. 84 3. 7 ± 0. 3 8 3. 2 ~ 4. 0 0. 10 8. 65 Length of glenoid cavity 3. 0 ± 0. 2 5 2. 6 ~ 3. 2 0. 05 7. 67 2. 8 ± 0. 3 8 2. 4 ~ 3. 0 0. 07 9. 29 Width of glenoid cavity 7. 4 ± 0. 3 5 7. 2 ~ 7. 9 0. 09 4. 19 6. 9 ± 0. 5 8 6. 1 ~ 7. 6 0. 26 7. 39 0. 050 Length of humerus along midline 4. 1 ± 0. 8 4 3. 53 ~ 5. 3 0. 69 20. 24 3. 7 ± 0. 3 7 3. 0 ~ 4. 0 0. 12 9. 19 Width of humerus proximally 4. 5 ± 0. 2 5 4. 2 ~ 4. 8 0. 05 4. 89 4. 1 ± 0. 5 8 3. 5 ~ 4. 7 0. 21 11. 22 Width of humerus distally 8. 3 ± 0. 5 5 7. 6 ~ 8. 92 0. 30 6. 51 7. 4 ± 0. 8 8 6. 1 ~ 8. 2 0. 64 10. 81 0. 044 Length of radius along midline 3. 2 ± 0. 3 4 2. 9 ~ 3. 6 0. 09 9. 38 2. 9 ± 0. 30 6 2. 4 ~ 3. 2 0. 09 10. 31 Width of radius proximally 4. 7 ± 0. 2 5 4. 4 ~ 4. 9 0. 04 31. 34 4. 2 ± 0. 55 8 3. 5 ~ 4. 8 0. 30 12. 85 Width of radius distally 7. 0 ± 0. 6 5 6. 3 ~ 7. 8 0. 31 7. 95 6. 4 ± 0. 5 8 5. 7 ~ 7. 2 0. 25 7. 81 Length of ulna along midline 3. 5 ± 0. 2 4 3. 3 ~ 3. 7 0. 04 5. 46 3. 3 ± 0. 42 7 2. 8 ~ 3. 9 0. 18 12. 85 Width of ulna proximally 3. 1 ± 0. 3 4 2. 7 ~ 3. 4 0. 09 9. 58 2. 9 ± 0. 53 7 2. 3 ~ 3. 9 0. 28 18. 05 Width of ulna distally 7. 9 ± 0. 4 4 7. 3 ~ 8. 2 0. 17 5. 19 7. 5 ± 1. 5 9 4. 6 ~ 9. 5 2. 29 20. 13 Length of pelvic rudiment bone * t- CV * Two sided t-test CV shows the coefficient of variation.
150 Chinese Journal of Zoology 45 14 5 6 7 Ⅱ.. 210. 8 Ⅳ. 382-389. 10 2003 22 18-20. 1999 18 26-27. 13 1 Jefferson T A Van Waerebeek K. Geographic variation in skull morphology of Humpback Dolphins Sousa spp.. Aquatic Mammals 2004 30 3-17. 2 Flower W. Description of the skeleton of the Chinese white dolphin Delphinus sinensis Osbeck. Transactions of the Zoological Society of London 1870 7 151-160. 3 Porter L J. A redescription of Sousa chinensis Osbeck 1765 Mammalia Delphinidae and designation of aneotype. Bulletin of the Natural History Museum Zoology Series 2002 68 27-37. 4 Porter L J. The taxonomy ecology and conservation of Sousa chinensis Osbeck 1765 Cetacea Delphinidae in Hong Kong Waters. Ph. D. dissertation HK The University of Hong Kong 1998.. Ⅰ.. 1997 16 473-478. Jefferson T A. 1999 18 205 - Jefferson T A. Ⅲ.. 1999 18 211-215. 9 Jefferson T A.. 1999 18. Ⅰ.. 11. Ⅱ.. 2004 23 18-20. 12.... 1997 17 73-74. 14.. 1982 3 1 67-74. 15.. 1996 15 3-8. 16.. 5. Mammals. London Academic Press 1994 23-42.. 1978 1 105-110. 1999. 17 Jefferson T A Hung S K. A review of the status of the Indo-Pacific Humpback Dolphin Sousa chinensis in Chinese Waters. Aquatic Mammals 2004 30 149-158. 18 Jefferson T A. Population biology of the Indo-Pacific Hump-backed Dolphin in Hong Kong Waters. Wildlife Monographs 2000 114 3-56. 19 Ross G B Heinsohn G E Cockcroft V G. Humpback dolphins Sousa chinensis Osbeck 1765 Sousa pumbea Cuvier 1829 and Sousa teuszii Kukentha 1892 Ridgeway S H Harrison R. Handbook of Marine