Improved method for sectioning pectoral spines of catfish for age determination
Journal of Freshwater Ecology
- Marc A. Blouin and Glenda R. Hall
A modified low-speed saw provided fast and precise sectioning of catfish pectoral spines for use in aging studies. In one hour, 10–15 spines can be sectioned, the sections mounted, and the annuli counted.
Two methods commonly used to section ictalurid pectoral spines are (1) acid decalcification, followed by the use of a razor blade or microtome to slice the softened spines, and (2) cutting hard spines with electric saws. Decalcifying methods are time-consuming, and we had difficulty attaining the proper spine consistency for sectioning when we used decalcification techniques. Electric saws with toothed blades tended to obliterate the first-year annulus at the periphery of the central lumen on spines of channel catfish (Scholl 1968). A low speed saw equipped with two, thin parallel diamond blades was used to section fish fin rays and spines (Shepard and Nichy 1984), but drawbacks are that the preparation is time-consuming and the blades tend to warp.
We used a low speed saw with a thick (0.3 mm), single blade for slicing the pectoral spines of brown bullheads (Ictalurus nebulosus) with fast, accurate and reproducible results. We also successfully sliced the pectoral spines of channel catfish (Ictalurus punctatus) and black bullhead (Ictalurus melas).
The advantages of this method are: (1) spine sections are clear, with uniform thickness and little tissue damage; (2) no time-consuming procedures are necessary; (3) the original spine remains intact for future sectioning; and (4) the thick, single blade does not warp.
Additional publication details
- Publication type:
- Publication Subtype:
- Journal Article
- Improved method for sectioning pectoral spines of catfish for age determination
- Series title:
- Journal of Freshwater Ecology
- Year Published:
- Taylor & Francis
- Contributing office(s):
- Great Lakes Science Center
- 2 p.
- First page:
- Last page:
- Online Only (Y/N):
- Additional Online Files (Y/N):