Diet and feeding intensity of sardine Sardina pilchardus: correlation with satellite-derived chlorophyll data

Abstract

Spatio-temporal variability of the diet of sardine Sardina pilchardus off Portugal was examined through analysis of the stomach contents of fish collected every 14 d from the west and south of Portugal during 2003Portugal during /2004. Dietary composition of the modal sardine length class was assessed by determining the frequency of occurrence and carbon content of identified prey, and these 2 parameters were combined to estimate a modified index of relative importance of prey (mIRI). The most important prey for sardines were zooplankton, comprising crustacean eggs, copepods, decapods, cirripedes and fish eggs, dinoflagellates and diatoms (particularly the toxin-producer genus Pseudo-nitzschia), which together accounted for > 90% of the estimated dietary carbon. Dietary seasonality was similar for both areas, except that the contribution of phytoplankton was higher for fish from the west Portuguese coast, where upwelling events are stronger and recurrent during spring and summer months. The predominance of prey < 750 μm in sardine diet suggests that filter feeding is the dominant feeding mode used in the wild. Feeding intensity was similar for both sexes and for fish of different length classes and was higher on the west coast than in the south, which is probably related to the higher productivity of the west coast. Although there was high inter-annual variability in feeding intensity, this parameter was highest for both areas during spring and winter months. Temporal variability in satellite-derived chlorophyll a matched the temporal variability in the dietary contribution by phytoplankton and of sardine feeding intensity, suggesting further investigation of the potential use of satellite-derived chlorophyll a data as a proxy for sardine feeding intensity. KEY WORDS: Sardina pilchardus · Stomach analysis · Feeding intensity · SeaWIFSResale or republication not permitted without written consent of the publisher

Seasonal pattern of population dynamics, spawning activities, and diet composition of sardine (Sardina pilchardus Walbaum) in the eastern Adriatic Sea

“…The observed seasonal alternations of allometric condition factor and fullness index additionally confirmed that sardines were in the best condition at the beginning of the spawning season, for which they prepared themselves by higher feeding intensity, leading to higher storage of consumed energy. However, this should be further investigated, as in upwelling areas (Garrido et al, 2008) diet seasonality might be linked not only to the reproduction cycle but also to some other environmental conditions.…”

“…Sardine is a batch spawner with indeterminate fecundity (Blaxter and Hunter, 1982;Ganias et al, 2003). According to the existing sardine diet-related information, it is evident that sardine feeding preferences or mode (filter or particulate feeding) largely depend on the environmental conditions of the region from which it originated (Garrido et al, 2007(Garrido et al, , 2008Costalago et al, 2015). Nevertheless, omnivory in the sardine is well documented worldwide (Navarro, 1952;Cunha et al, 2005).…”

Trophodynamics of anchovy in a non-upwelling system: direct comparison with sardine

“…Although phytoplankton has been found to contribute significantly to the diet of the 2 species in certain areas/conditions (e.g. James 1987, Garrido et al 2008, it is well established that the bulk of their dietary carbon is of zooplanktonic origin (e.g. James 1987, van der Lingen et al 2006, Espinoza & Bertrand 2008, Garrido et al 2008, Espinoza et al 2009, Nikolioudakis et al 2012.…”

“…SPF are omnivorous planktivores, able to switch between filter-and particulate feeding modes (James 1987, van der Lingen et al 2006, Garrido et al 2007, and they derive the bulk of their dietary carbon from zooplankton, mainly copepods and euphasuiids (e.g. Garrido et al 2008, Espinoza & Bertrand 2008, Espinoza et al 2009, Nikolioudakis et al 2012.…”

Culture viability of <em>Sardina pilchardus</em> (Fish, Teleost): Preliminary results of growth in captivity up to 18 months

“…Garrido et al (2007Garrido et al ( , 2008 described both the feeding behaviour of sardines under culture conditions, and the diet and food intensity in the wild. However, none of these studies has focused on long-term growth in captivity.…”