Limitations of Using Otoliths Recovered in Scats to Estimate Prey Consumption in Seals
Limitations of Using Otoliths Recovered in Scats to Estimate Prey Consumption in Seals
复制标题
使用粪便中发现的耳石来估计海豹猎物消耗的局限性
DOI：
10.1139/f85-180
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
J. Neilson
中科院分区：
文献类型：
--
作者：
J. Silva;J. Neilson
在喂食圈养斑海豹 Phoca vitulina 的三个长度级别的鲱鱼 Clupea harengus（30-35、20-25 和总长度）中，仅从 30-35 厘米长的鲱鱼中发现了耳石；这些耳石中只有 4% 被回收。根据耳石的表面积与体积之比，预测其他鱼类在粪便中的代表性也同样不足。消化后，耳石显示出较少的环带以及长度和宽度的减少。海豹粪便中的鲱鱼耳石仅表明大型鲱鱼（总长度）的消耗，不能用于估计消耗的猎物数量。如果计算是基于这些参数与未消化耳石测量值之间的标准关系，则鲱鱼耳石的部分消化将导致鱼龄、长度和重量的低估。
Of three length classes of herring, Clupea harengus (30–35, 20–25, and total length), fed to a captive harbor seal, Phoca vitulina, otoliths were recovered only from herring 30–35 cm long; of these otoliths only 4% were recovered. Using surface area to volume ratios of otoliths, other fish species were predicted to be similarly underrepresented in scats. After digestion, otoliths showed fewer annuli and a reduction in length and width. Herring otoliths in harbor seal scats indicated the consumption of large herring ( total length) only and could not be used to estimate numbers of prey consumed. The partial digestion of herring otoliths will result in underestimates of fish age, length, and weight if calculations are based on standard relationships between these parameters and measurements from undigested otoliths.