Sastav prehrane i preklapanja prehrambenih navika kod 43 vrste riba u sjevernom Egejskom moru, Grčka

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.Ova studija bavi se sastavom prehrane 43 vrste koje spadaju u neke od najbrojnijih vrsta riba u sjevernom Egejskom moru, Grčka. Prema analizi prehrane i razine frakcijskih trofičkih razina o kojima se prije izvještavalo u literaturi, 20 vrsta od ukupnog broja istraživanih su svežderi koji preferiraju životinje, a druga polovica su mesojedi (15 od kojih preferira ribe i glavonošce, a sedam ih preferira ribe i deseteronošce) dok je Parablennius gattorugine jedini zabilježeni svežder koji preferira biljke. Naposljetku, prema rezultatima Schoenerova indeksa, preklapanja prehrambenih navika zabilježena su kod malog broja slučajeva (33 od 903 ispitivana para). Ipak, konkurencija među vrstama kod kojih se prehrambene navike preklapaju može se umanjiti bilo morfološkim diferencijacijama bilo segregacijom staništa

Feeding and ecomorphology of three clupeoids in the N Aegean Sea

The present study examines the feeding habits of anchovy (Engraulis encrasicolus), sardine (Sardina pilchardus) and round sardinella (Sardinella aurita). The results are combined with previously published information on feeding-related morphological features (i.e. mouth area, intestine length and tail area) in order to explore morphological affinities between species and the effect of ecomorphology on their co-existence. These species were mainly zooplanktivorous and no dietary differences were found with sex and season. Anchovy preyed mainly on Crustacea larvae, whereas sardine and round sardinella on Copepoda. In the majority of cases (>90%), the individual fractional trophic level of all species ranged between 3.0 and 3.5, classifying them as omnivores with preference to animals. The feeding-related morphological features differed between anchovy and the two other species, whereas only intestine length differed between sardine and round sardinella. The fact that round sardinella’s diet and morphology show a greater resemblance to those of sardine, further support the hypothesis that is a particulate feeder as sardine. Hence the three species tend to exploit the same food resources differently throughout the year. Thus, they make best use of the environment and its resources, in order to avoid competition and achieve optimum feeding conditions throughout their life cycle

An update on the feeding habits of fish in the Mediterranean Sea (2002-2015)

In this study we updated the previous compilation of the feeding habits and trophic levels (TROPHs) of Mediterranean fish. In total, 172 publications were retrieved and analysed. Collected data refer to 146 species, with a TROPH value ranging from 2.00 to 4.54. The analysis of TROPH distribution verified the previously proposed classification of species into functional trophic groups. Overall, information on diet composition exits for 203 fish species out of the >700 fishes from the Mediterranean, a fact clearly showing that feeding habits are understudied despite their importance in ecological applications and fisheries management. More than half (60.6%) of these species are classified as omnivores with preference to animal material, 36.5% are carnivores, 1.9% are omnivores with preference to plants, and two (i.e. Siganus luridus and S. rivulatus) are pure herbivores. Finally, towards the direction of filling in information gaps, recommendations for future research are given

Prehrana i hranilišta traglja Spicara maena i gire S. smaris (Pisces, Osteichthyes, Centracanthidae) u sjevernom dijelu Egejskog mora

n the present paper we studied the diet of two centracanthid species , Spicara maena and S. smaris,in the N Aegean Sea. Overall, 282 and 118 individuals were examined, respectively. Both species preyed upon zooplankton, notably Copepoda (54.3 and 63.5%, respectively). S. maena included in its diet a wider variety of food items (36 taxa) compared to S. smaris (12 taxa). The individual trophic levels for both species ranged from 3.00 to 4.50 (mean values ± strandard error: 3.21±0.058 for S. maena and 3.05±0.068 for S. smaris ). Given their trophic position and local abundance, they play a crucial role in the flux of energy from low to high trophic levels of the Aegean benthic and pelagic food webs.U ovom radu prikazani su rezultati istraživanja prehrane dviju vrsta iz porodice girovki, traglja Spicara maenai gire S. smaris, sa sjevernog područja egejskog mora. Istraženo je 282 jedinki traglja te 118 jedinki gire. Obje vrste u svojoj prehrani koriste zooplankto, osobito veslonošcec opepoda (54.3% tragalj, 63.5% gira). Tragalj u svojoj prehrani koristi znatno širi raspon organizama (36 svojti) dok gira znatno manje (12 svojti). Pojedinačna trofička razina za obje vrste se kreće od 3.00 do 4.50 (srednja ijednost±standardna pogreška: 3.21±0.058 za traglja i 3.05±0.068 za giru).glede njihove trofičke razine i lokalne brojnosti, obje vrste igraju značajnu ulogu u protoku energije od najnižih do najviših trofičkih razina u e gejskom moru u okviru pelagijskog i bentoskog lanca prehrane

Prehrana i hranilišta traglja Spicara maena i gire S. smaris (Pisces, Osteichthyes, Centracanthidae) u sjevernom dijelu Egejskog mora

n the present paper we studied the diet of two centracanthid species , Spicara maena and S. smaris,in the N Aegean Sea. Overall, 282 and 118 individuals were examined, respectively. Both species preyed upon zooplankton, notably Copepoda (54.3 and 63.5%, respectively). S. maena included in its diet a wider variety of food items (36 taxa) compared to S. smaris (12 taxa). The individual trophic levels for both species ranged from 3.00 to 4.50 (mean values ± strandard error: 3.21±0.058 for S. maena and 3.05±0.068 for S. smaris ). Given their trophic position and local abundance, they play a crucial role in the flux of energy from low to high trophic levels of the Aegean benthic and pelagic food webs.U ovom radu prikazani su rezultati istraživanja prehrane dviju vrsta iz porodice girovki, traglja Spicara maenai gire S. smaris, sa sjevernog područja egejskog mora. Istraženo je 282 jedinki traglja te 118 jedinki gire. Obje vrste u svojoj prehrani koriste zooplankto, osobito veslonošcec opepoda (54.3% tragalj, 63.5% gira). Tragalj u svojoj prehrani koristi znatno širi raspon organizama (36 svojti) dok gira znatno manje (12 svojti). Pojedinačna trofička razina za obje vrste se kreće od 3.00 do 4.50 (srednja ijednost±standardna pogreška: 3.21±0.058 za traglja i 3.05±0.068 za giru).glede njihove trofičke razine i lokalne brojnosti, obje vrste igraju značajnu ulogu u protoku energije od najnižih do najviših trofičkih razina u e gejskom moru u okviru pelagijskog i bentoskog lanca prehrane

Nova saznanja o prehrani lesepsijske žutopjegave četverozupke Torquigener flavimaculosus Hardy i Randall, 1983. u istočnom Sredozemlju

The stomach contents of 104 individuals of Torquigener flavimaculosus from Cyprus were examined. The analysis revealed that it is an omnivorous species with a preference to animal prey, especially invertebrates with limited mobility (crustaceans, molluscs, echinoderms). The study of the length-weight relationship indicated a negative allometric growth for both sexes. It seems that its preference to consume invertebrates, its high toxicity due to high concentrations of tetrodotoxin in its tissues and some other biological characteristic reinforce it characterization as invasive and monitoring actions should be designed for such species.Istraživan je sadržaj želudca 104 jedinke Torquigener flavimaculosus sa Cipra. Analizom je utvrđeno da se radi o svejedu u čijoj prehrani prevladava životinjski plijen, posebice beskralješnjaci ograničene pokretljivosti (rakovi, mekušci, bodljikaši). Istraživanje odnosa dužine i mase tijela pokazalo je negativan alometrijski rast za oba spola. Čini se da njegova sklonost konzumiranju beskralježnjaka, visoka toksičnost zbog visokih koncentracija tetrodotoksina u tkivima i neke druge biološke karakteristike pojačavaju njegovu karakterizaciju kao invazivne vrste, pa stoga za takve treba osmisliti mjere praćenja i kontrole