小鳁鲸的一些生物学测量数据

2004年6月山东省威海石岛的渔民偶然误捕了一头须鲸,经作者鉴定,此标本系小鳁鲸(Balaenoptera acutorostrata)。主要鉴别特征:头背面的嵴明显;左右鳍肢各有一白色的横斑;有282对白色的鲸须板。同时还对其进行了较详细的观察和测量,值得一提的是此鲸存有异常现象:有一假脐,乳沟位于生殖裂后端而非生殖裂的两旁。

Utility of the Transition Phase in Earplugs of the North Pacific Common Minke Whale as an Indicator of Age at Sexual Maturity

Whale age at sexual maturity is one of the most important biological parameters that can be used in stock management and population analysis. Earplugs have been widely used as an indicator of age among rorquals. It has also been accepted that the transition phase in the earplug can be used as an indicator of age at sexual maturity in fin whales, sei whales, and Antarctic minke whales. This study aimed to provide further insight into the utility of the transition phase as an indicator of age at sexual maturity in the North Pacific common minke whales, which has not yet been clarified. The relationship between sexual maturity and transition phase in earplugs was examined using 981 readable earplugs from common minke whales that were sampled at the JARPN and JARPN II scientific permit survey platform in the western North Pacific from 1994 to 2011. The transition phase was recognized in 53.2% of mature males and in 58.6% of mature females. Most whales in which the transition phase was recognized in the earplug were sexually mature. A significant correlation was found between the number of corpora and time after sexual maturation, as revealed by the transition phase, demonstrating that the transition phase is a valid indicator of age at sexual maturity in common minke whales. However, it was difficult to recognize the transition phase in whales that had recently attained sexual maturity because insufficient time had elapsed since its formation. To avoid potential bias, the use of earplugs as an indicator of age should be restricted to whales more than 12 years old.

一头遭鲨鱼袭击和误捕的小须鲸幼仔

小须鲸（Balaenoptera acutorostrata）（马克·卡沃丁，2000；周开亚等，2001）也称小媪鲸（王丕烈，1979，1990，1999；王宇，1991），国际捕鲸委员会IWC将其列为鲸目（Cetacea），IUCN则列为鲸偶蹄目（Cetartiodactyla），须鲸亚目（Mysticeti），须鲸科（Balaenopteridae），分布于世界各海洋中，是分布最广泛的一种须鲸，有明显的地方变异（周开亚等，2001）。