文章基本信息

标题：Demographics and Chronology of a Spawning Aggregation of Blue Sucker ( Cycleptus elongatus ) in the Grand River, Missouri, USA
本地全文：下载
作者：Jason C. Vokoun ; Travis L. Guerrant ; Charles F. Rabeni 等
期刊名称：Journal of Freshwater Ecology
印刷版ISSN：0270-5060
电子版ISSN：2156-6941
出版年度：2003
卷号：18
期号：4
页码：567-575
DOI：10.1080/02705060.2003.9663997
出版社：Taylor & Francis
摘要：The blue sucker (Cycleptus elongatus) was sampled as individuals arrived, spawned, and departed from a spawning rime in the Grand River of northcentral Missouri, USA. The Grand River basin was not known to support blue sucker reproduction with few individuals ever recorded. The spawning site is unique in character for the lower river. Individuals began arriving in early April when water temperatures reached 10-12 °C. Females with freely-flowing roe were sampled in late April after a large rise in river stage and concurrent lowering of the water temperature 4-5 degrees to 16.5 °C. The spawning aggregation had a mean age of 15 y and ranged from 9 to 22 y based on scales that probably underestimated true ages. Males outnumbered females 5.5:1. Mean length was 659 mm for males and 721 mm for females. Females were longer at age than males and no significant age-length relationship was evident.