Growth of Bluegills in a New Lake, with Particular Reference to False Annuli
- 1 January 1954
- journal article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 83 (1) , 58-75
- https://doi.org/10.1577/1548-8659(1953)83[58:gobian]2.0.co;2
Abstract
McFarland Pond was constructed in 1946 and stocked with 23 2‐year‐old bluegills (Lepomis macrochirus) in 1947. Scales from the 1947 to 1949 year classes of bluegills were studied with particular attention to the recognition of false and true annuli. No consistent changes in coefficient of condition, K, were noted except for a tendency for the K value to increase with increase in length of fish. Annulus formation occurred from mid‐February to mid‐June, with most fish forming annuli in the last half of May or early June. Although the body‐scale relationship is better described by a third‐degree equation, calculated lengths based upon a straight‐line relationship were nearly as accurate. The brood stock grew rapidly when first placed in the lake. The 1947 year class grew less in 1947 than did the 1948 and 1949 young of the year during their first summers. Late spawning was probably the cause of the poor growth in 1947. By 1949, the bluegills were severely stunted and showed little growth after they reached 1 year of age. Most of the seasonˈs growth was completed by early July. The faster growing individuals disappeared before their third year. Male bluegills showed more rapid growth than females after the first year of life. About 90 percent of the 1948 and 1949 year class bluegills showed checks on their scales before the first annulus whereas only 10 percent of the 1947 year class bluegills showed such false marks. False marks after the first annulus seem to be connected with sexual activity. Suggestions are given for recognizing false annuli.This publication has 0 references indexed in Scilit: