Skip to main content

Combined study of daily growth variability and nitrogen–carbon isotopic signature analysis of schooling

Buy Article:

$51.00 plus tax (Refund Policy)


A combined study of Alborán Sea Sardina pilchardus larval daily growth and isotopic signature was carried out to elucidate the cause of morphometric differences observed in a single larval school whereby the standard length (L S) v. dry mass (M D) relationship differentiated a heavier‐by‐size larval group from a lighter larval group. The daily growth analysis revealed that this difference originated from two larval growth patterns, where a fast growing population (F) in contrast to a slow‐growing larval population (S) was distinguished. The S‐growing larval cohort had a significantly higher nitrogen (N) content as a result of greater somatic mass build up with time in the form of structural proteins. Alternatively, the F‐growing population showed a significantly greater amount of carbon (C) content with age, indicating faster metabolic rates of C accretion compared to the S‐growing group. In consequence, the C:N ratios of the F‐growing larvae were significantly higher than the S‐group. C:N ratios of both larval populations showed significant linear decrease with age (and size), while K showed an inverse relationship. The stable isotopes of N did not show significant differences between the S and F‐growing larvae. In F‐growing larvae, however, a significant linear increase in δ 15N (by age class) was observed, indicating that as larvae undergo ontogenetic development, trophic level tends to increase. This was also made evident by the significant decrease in age of δ 15N coefficients of variation (by age class). The higher δ 13C values in the S‐growing larvae were related to the lower growth rates observed in this group. These results suggest a broader trophic flexibility in younger larvae, but moving towards a trophic specialization and more selective diets with age. This trophic specialization shows a tendency of a greater prey size with age. These findings suggest that S‐growing larvae have a more omnivorous diet than the F‐growing ones.

Document Type: Regular Paper


Publication date: October 1, 2011

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more