Effects of preservation on pigmentation and length measurements in larval lampreys
The effects of two methods of preservation (fixation and storage in 10% formalin, and fixation in 10% formalin followed by storage in 95% alcohol) on pigmentation and morphometric features used for identification of larval Ichthyomyzon lampreys were analysed. Both short‐term (3 weeks) and long‐term (6 months) studies were conducted using digital analysis of images of fresh and preserved lampreys. Six standard morphometric lengths and 10 areas of pigmentation were analysed. All measurements were significantly affected by preservation. Preservative type affected pigmentation and morphometric characteristics differently, and characters were affected to different degrees. Multiple measurements over time showed that almost all changes occurred within 3 weeks of preservation. Regression equations allowed for accurate correction of preservation effects on morphometric measurements, but the effects on pigmentation levels were less predictable. Effects of preservation on larval lampreys need to be considered when comparing fresh and preserved specimens because they influence critical identification features.
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Document Type: Regular Paper
Sea Lamprey Control Centre, 1 Canal Drive, Sault Ste. Marie, P6A 6W4, Canada,
Great Lakes Lab for Fisheries and Aquatic Sciences, 867 Lakeshore Drive, Bington, L7R 4A6, Canada,
Great Lakes Institute for Environmental Research, 401 Sunset Ave., Windsor, N9B 3P4, Canada and
Fisheries & Wildlife Department, Oregon Hatchery Research Center, Oregon State University, Corvallis, OR 97331-3803, U.S.A.
Publication date: 2006-04-01