黄渤海常见鱼类鳞片的形态特征

本研究选取黄渤海28种常见鱼类为研究对象,描述不同部位鱼鳞的形态特征。结果显示,鲱形目鱼鳞鳞焦不明显,辐射沟呈横向或波纹状分布;鳕形目鱼鳞密布小方块状特殊结构;灯笼鱼目鱼鳞辐射沟数目少;鲈形目和鲉形目鱼鳞呈卵圆形或矩形,前区边缘有不规则钝齿结构;鲽形目鱼鳞前区辐射沟多而密集。不同科属鱼鳞在形状、鳞焦位置、环片形状、辐射沟特征、栉齿分布和侧线管形状等形态特征上有明显差异,可用于不同分类阶元的鉴定。本研究构建的鱼鳞形态信息库为鱼鳞沉积信息分析等基于鱼鳞形态的种类鉴别提供了基础资料。

Morphological characters of scales in some common fish from the Yellow and Bohai Seas

  Previous fish population studies were mainly based on short historical catch records. However, the short time-scale of such records and the almost complete overlap in time between the records and large-scale fishery exploita- tion are of limited use when assessing long-term variations in fish populations and distinguishing the relative impor- tance between natural and anthropogenic factors. Therefore, it is essential to develop long-term time series of fish stocks beginning when human impacts were minimal to understand the causes of variability in fish stocks (natural and/or anthropogenic). Well-preserved fish scales from sediment records are useful indicators for revealing the history of fish population dynamics over the last few centuries. Fish scale fossils discovered in sediment are primarily identi- fied by comparison with fresh fish material collected in the same area. Therefore, developing a fish-scale database is useful for identifying species from fish-scale fossils and reconstructing the population using a sedimentary-scale record analysis. The morphological structure of fish scales is stable and contains species-specific characters. These morpho- logical characters can be used to identify species from sedimentary records. Twenty-eight common fish species in the Yellow and Bohai Seas were chosen as study objects, and the morphological characters of their scales were described and compared. Distinguishable scale characteristics of different orders, families, and genera include: (1) overall scale shape; (2) appearance and manifestation of circuli; (3) position of the focus; (4) number and manifestation of radii; (5) appearance of the anterior, posterior, and lateral fields of the scale; (6) appearance and position of the lateral-line canal; and (7) appearance and number of ctenii. The results show that scales with a poorly defined focus and a trans- verse or wavy radii pattern were uniquely in Clupeiformes; the number and manifestation of radii were regarded as identifying features of different genera in Clupeiformes. Because of the intertwined patterns of the radii and ridges, dense small blocky shapes on the scale surface were unique in the scales of Gadiformes. Scales of Myctophiformes had a relatively small number (2–4) of radii and large arcs in the posterior field. A rectangular and oval shape with a nearly right angle in the anterior field was the most common character among scales in Perciformes and Scorpaeniformes, ex- cept in Chaeturichthys stigmatias and Pampus argenteus; the distribution of ctenii and the shape of the lateral-line canal were identifying features of different genera in Perciformes and Scorpaeniformes. An oblong shape with dense radii in the anterior field was a unique character in the scales of Pleuronectiformes. Distinguishable characters, including over- all scale shape, distribution of ctenii, and the shape of the lateral-line canal, were found in different genera of Pleu- ronectiformes. However, these families and genera are usually distinguished by combinations of the characters men- tioned above. This study provides basic information on identifying species for a scale sedimentary record analysis based on fish-scale morphology. This type of analysis is expected to improve the veracity of species identification and reli- ability of scale sedimentary record analysis by collecting fish scales of more species, quantifying scale morphological characters among close relatives, and studying the geographic variations of scales in inter-species. When combined with other biogeochemistry and productivity proxies, a scale sedimentary record analysis can be compared with changes in ocean productivity and help illuminate factors driving changes in ocean productivity, which is the ultimate goal of our ongoing work.