Feeding and ecomorphology of three clupeoids in the N Aegean Sea (original) (raw)
Related papers
2015
The feeding of round sardinella, Sardinella aurita, was investigated in the Izmir Bay, central Aegean Sea of Turkey, during October 2010 September 2011. Examined of the 434 stomach contents, 39 (9.0%) had emty. Most empty stomach were encountered during autumn (19.1%), followed by (8.0%) summer, winter (2.2%) and spring (2.0%). A total number of 14266 prey items and forty eight species were identified, belonging to six major groups: Polychaeta, Crustacea, Mollusca, Chaetognatha, Tunicate and Teleostei. Finally crustaceans (particularly copepods) were the most important food item in terms of index of relative importance. At least 31 copepod species were identified, where Calanoida, Oithona nana, Oncaea media and Oithona plumifera appeared all year round with %IRI ≥ 10.
ICES Journal of Marine Science, 2010
Morote, E., Olivar, M. P., Villate, F., and Uriarte, I. 2010. A comparison of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) larvae feeding in the Northwest Mediterranean: influence of prey availability and ontogeny. – ICES Journal of Marine Science, 67: 897–908. The feeding ecology of the larvae of the two most important small pelagic species in the western Mediterranean, anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus), is investigated. Samples were collected in early summer (anchovy) and autumn (sardine). Composition of the diet and prey selectivity were compared over the course of ontogeny in anchovy (2.7–14.5 mm standard length, SL) and sardine (5.5–15.8 mm SL) larvae. Anchovy larvae begin feeding on prey items >150 µm at smaller sizes than sardine larvae, and the diets of both species are based mainly on copepod nauplii and postnauplii. Seasonal differences in the composition of the plankton influenced the contributions of prey types to t...
Belgian journal of …, 2005
Acoustic survey data were combined with hydrological parameters with the aim of understanding the relationships between the spatial distribution of anchovy and sardine and environmental regimes. Acoustic and concurrent hydrological sampling was carried out in the Northern Aegean Sea (eastern Mediterranean) during June 1995 and June 1996. In order to examine hydrological parameter selection by anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus), cumulative distribution functions were estimated. Both species were significantly associated with areas of deeper surface and upper mixed layers, which implied an association of anchovy and sardine with anticyclones. Within the range of available temperatures and bottom depths, sardine further showed a significant affinity to warm as well as to shallow waters. These results are discussed in relation to species' life histories and existing knowledge of oceanographic features in the surveyed area.
Diet of sardine Sardina pilchardus: an ‘end-to-end’ field study
The diet of sardines was analyzed from samples collected at a coastal site in the North Aegean Sea (eastern Mediterranean) in July 2007 and July 2008 (stratification periods), and in December 2007 (early phase of the mixing period) and February 2009 (late phase of the mixing period). Concurrent measurements of environmental and planktonic community variables (from bacteria to mesozooplankton) were carried out to infer major trophic pathways in the pelagic food web and determine how these pathways are related to sardine prey selection. The bulk of the dietary carbon in adults was derived from calanoid copepods, >1 mm total length, although the diet was numerically dominated by phytoplankton. In juveniles, phytoplankton consumption was negligible. The diet composition and prey selection seemed to be driven by the availability of large prey. During summer, microbial processes prevailed (the ratio of autotrophs < 20 µm:> 20 µm was 13 to 15, and the ratio of autotrophic to heterotrophic pico-and nanoplankton biomass was < 0.5), the mean size of mesozooplankton was smaller, and filter-feeding cladocerans and appendicularians were very abundant. In February 2009, autotrophs > 20 µm dominated the carbon budget, and the abundance of larger copepods (e.g. Centropages) was high. In December 2007, when waters were mixed but still relatively warm, both the 'microbial' and 'classical' (herbivorous) trophic pathways seemed to be important. The mean size of mesozooplankton (copepods and cladocerans) in sardine stomachs was highly correlated with their mean size in the field, and the latter was in turn highly positively correlated with the concentration of diatoms. Finally, a strong negative relationship between the Shannon-Wiener diversity index and average size of mesozooplankton prey in the stomachs was found, which could be explained in terms of the interplay of feeding modes, i.e. filter (non-selective) and particulate (selective) feeding.
The gut contents of Sardina pilchardus specimens captured in Izmir Bay were examined in order to determine their feeding regimes. Of the 365 stomachs examined, 321 (87.95%) contained food and 44 (12.05%) were empty. Analysis of gut contents verified that S. pilchardus feeds on zooplankton. The most important group in the diet of S. pilchardus was copepods (79.79%). Decapod crustacean larvae (8.17%) and bivalves (3.18%) were second and third, respectively, in order of importance. The application of analysis of variance to monthly data of numerical percentage, weight percentage, frequency of occurrence and index of relative importance indicated that there was no significant difference between months. Oncaea media was the most dominant species for six months of the year. Euterpina acutifrons, Centropages typicus, Calanoida, Oncaea sp. and Corycaeus sp. were the most dominant for March, April, May, September, October and December.
Journal of Applied Ichthyology, 2008
Feeding habits of the round sardinella Sardinella aurita (Valenciennes, 1847) were studied in the central Mediterranean Sea from a sampling of 254 specimens caught seasonally from April 2004 to January 2005. Stomach content analysis showed a zooplankton diet mainly composed of crustaceans, mostly copepods, but also of a large variety of prey categories. The relationship among dietary descriptors pointed to some feeding variation in its diet, which was also confirmed by corresponding analysis. Correlation analysis and analysis of variance of the sample (fish) scores indicated size-related and temporal variations in the round sardinella diet. Small S. aurita fed on smaller sized prey categories, compared to larger fish in which larger zooplankters frequently occurred. While size related variations in the diet seemed likely correlated to changes in the gill arch structure, temporal variations could be due to seasonal food resource availability. Given the few studies carried out on S. aurita in the Mediterranean Sea, these results contribute to improving knowledge on the feeding habits of this species, which is progressively extending its distribution northward in the area.
Özet: Ege Denizi'nde bulunan beş derin deniz balığı: Argentina sphyraena, Glossanodon leioglossus, Chlorophthalmus agassizi, Hoplostethus mediterraneus ve Capros aper 2003 bahar mevsimi süresince ticari trol balıkçıları tarafından hedef dışı av olarak elde edilen örnekler olarak çalışılmıştır. Türlerin besin kompozisyonlarını belirlemek için mide içerikleri incelenmiştir ve türlerin trofik durumlarının özellikle karnivor seviyede yer aldığı görülmüştür. Beş predator türün besin kompozisyonunda iki esas av grubu bulunmuştur: Crustacea (copepodlar ve isopodlar gibi) ve Chaetognatha (Sagitta spp.).
Diet composition of the five deep sea fish from the Aegean Sea
The diets of five deep sea fish: Argentina sphyraena, Glossanodon leioglossus, Chlorophthalmus agassizi, Hoplostethus mediterraneus and Capros aper from the Aegean Sea were examined in the specimens caught as bycatch and discarded by commercial trawl fisheries during 2003 spring. Stomach contents were analyzed to determine their diet composition, which indicates that the trophic status of these species can be assigned primarily to the carnivore guild. Two major prey groups were found in the diet composition of all five predators: Crustaceans (like copepods and isopods), and Chaetognathans (Sagitta spp.).
Diet composition and overlap for 43 fishes in the North Aegean Sea, Greece
Acta Adriatica, 2017
This study presents the diet composition of 43 of some of the most abundant fish species from the North Aegean Sea, Greece. According to the diet analysis and fractional trophic level previously reported in the literature, 20 of the studied species were omnivores with a preference for animals and the other half were carnivores (15 with preference for fish and Cephalopoda, and seven with preference for fish and Decapoda), whereas Parablennius gattorugine was the only recorded omnivore with a preference for plant material. Finally, according to the results of Schoener’s index, diet overlap between species was recorded in a small number of cases (33 out of the 903 pairs examined). Yet, competition among diet-overlapping species may be minimised by either morphological differentiations and/or habitat segregation.