TITLE

Formation of ring marks in stocked tilapia juveniles (Oreochromis aureus/O. niloticus) (Perciformes: Cichlidae)

AUTHOR(S)
Ibañez, Ana L.; Romo-Coronel, Marco A.
PUB. DATE
September 2007
SOURCE
Revista de Biología Tropical;sep2007, Vol. 55 Issue 3/4, p1005
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Lake Metztitlán was dried up completely in the spring of 1998 and refilled in August of that year. In the period September-November, two cohorts of 1.6 million juveniles of a tilapia hybrid were stocked (Oreochromis aureus/O. niloticus), and monitored every month for one year. Since the date of birth of these juveniles was known, the analyses focused on whether the ring marks of the scales, sagittae and opercula or the circuli of the scales could be used to age them. The ring marks of the scales and opercula showed great variability, and the sagittae had a significant relationship with length, but it is unclear if at least the first ring mark could be formed at the hatchery and reflect changes in diet and/or tank movements in the fish farm. The circuli had a continuous regular behavior, with a formation rate of 10.38 ± 0.93 and 11.38 ± 0.95 circuli/month for the first and second cohorts, respectively. This proportion was maintained during the study period, and could be of help to calculate an approximate age of juveniles, especially in stocked fish that show multiple ring marks because of manipulation in fish farms and stocking events.
ACCESSION #
26474655

 

Related Articles

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics