The Raffles Bulletin of Zoology (2002)


We studied the growth and reproduction of finless porpoises in southern China, based on 86 specimens collected as strandings or fisheries bycatches in Hong Kong, southern Fujian Province, and Taiwan. Specimens were aged by sectioning and staining thin layers in the teeth, and counting dentinal and cemental growth layer groups (GLGS). There is a general darkening of the colour pattern from neonates through adults, and adults become relatively more slender. Growth is rapid in the first year and thereafter begins to level-off. There is evidence of some sexual dimorphism, with males growing somewhat larger than females. There is a distinct calving peak from October to January. Limited data on age and length at attainment of sexual maturity suggest that females reach maturity at about 137-150 cm and 5-6 years, and males at 138-154 cm and 4-5 years. The growth and reproductive parameters found in this study are similar to those determined previously for other populations of finless porpoises.