Link between environmental anomalies, growth and condition of pilchard Sardina pilchardus larvae in the northwestern Mediterranean

• Published in: Marine ecology. Progress series (Halstenbek) 2006-01, Vol.307, p.219-231
• Main Authors: CATALAN, Ignacio A, OLIVAR, M. Pilar, PALOMERA, Isabel, BERDALET, Elisa
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Marine; Sardina pilchardus; Sea water ecosystems; Synecology
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps307219

Relationships between environmental factors and the growth and condition of pilchard Sardina pilchardus (Walbaum) larvae were studied in November 1998 in the northwestern Mediterranean (NWM). Long-term growth of fish was assessed using otolith analysis and condition was assessed through histological and biochemical (RNA/DNA) indices. These measurements were conducted on larvae belonging to 2 station groups (A and B) previously defined through principal component analysis (PCA) on 7 environmental variables. Correlations between individual condition indices and environmental values at place of capture were also performed. Condition in environmental group A was significantly higher than in group B as assessed by both histological indices and RNA/DNA. Long-term growth, however, did not differ significantly between groups except for the otolith diameter vs. standard length (SL) relationship. The stations conforming to environmental group A were characterised by environmental ranges that would form a favorable habitat for larval success, including surface temperatures 5500 of other microzooplankters (T-N) m super(-3). Apart from the good agreement found between histological and RNA/DNA results, each approach offered different information: histological indices detected the largest portion of unfit larvae at size-ranges