Zooplankton of Sığacık Bay and its Role in the Dietary Composition of Barbary Fish (Anthias anthias L. 1758)

Project no. 32116 · Status: Kapanmış (Yayın bekleniyor) · 2024

Summary

<p> This&nbsp;study&nbsp;investigated&nbsp;the&nbsp;relationship&nbsp;between&nbsp;the&nbsp;seasonal&nbsp;qualitative&nbsp;and&nbsp;quantitative&nbsp;distribution&nbsp;of&nbsp;the&nbsp;zooplankton&nbsp;community&nbsp;in&nbsp;Sığacık&nbsp;Bay&nbsp;and&nbsp;the&nbsp;feeding&nbsp;composition&nbsp;of&nbsp;the&nbsp;swallowtail&nbsp;seaperch,&nbsp;<em>Anthias&nbsp;anthias</em>&nbsp;(Linnaeus,&nbsp;1758).&nbsp;Zooplankton&nbsp;samples&nbsp;were&nbsp;collected&nbsp;seasonally&nbsp;from&nbsp;six&nbsp;stations&nbsp;between&nbsp;April&nbsp;2024&nbsp;and&nbsp;February&nbsp;2025,&nbsp;while&nbsp;fish&nbsp;specimens&nbsp;were&nbsp;sampled&nbsp;monthly&nbsp;over&nbsp;a&nbsp;one-year&nbsp;period.&nbsp;Zooplankton&nbsp;samples&nbsp;were&nbsp;obtained&nbsp;using&nbsp;a&nbsp;UNESCO&nbsp;WP-2&nbsp;plankton&nbsp;net,&nbsp;and&nbsp;stomach&nbsp;contents&nbsp;were&nbsp;examined&nbsp;under&nbsp;a&nbsp;stereomicroscope.&nbsp;Feeding&nbsp;analyses&nbsp;were&nbsp;performed&nbsp;using&nbsp;numerical&nbsp;abundance&nbsp;(%N),&nbsp;frequency&nbsp;of&nbsp;occurrence&nbsp;(%F),&nbsp;gravimetric&nbsp;composition&nbsp;(%W),&nbsp;the&nbsp;Index&nbsp;of&nbsp;Relative&nbsp;Importance&nbsp;(IRI),&nbsp;Morato&nbsp;Index,&nbsp;and&nbsp;Chesson’s&nbsp;α&nbsp;selectivity&nbsp;index.</p><p> A&nbsp;total&nbsp;of&nbsp;19&nbsp;zooplankton&nbsp;groups&nbsp;and&nbsp;42&nbsp;copepod&nbsp;species&nbsp;were&nbsp;identified.&nbsp;Copepods&nbsp;were&nbsp;the&nbsp;baskın&nbsp;zooplankton&nbsp;group&nbsp;throughout&nbsp;the&nbsp;study&nbsp;period,&nbsp;reaching&nbsp;their&nbsp;highest&nbsp;abundances&nbsp;in&nbsp;spring&nbsp;(140.4&nbsp;ind.&nbsp;m⁻³)&nbsp;and&nbsp;autumn&nbsp;(141.1&nbsp;ind.&nbsp;m⁻³).&nbsp;The&nbsp;most&nbsp;abundant&nbsp;copepod&nbsp;taxa&nbsp;included&nbsp;<em>Nannocalanus&nbsp;minor</em>,&nbsp;<em>Clausocalanus</em>&nbsp;spp.,&nbsp;<em>Temora&nbsp;stylifera</em>,&nbsp;<em>Lucicutia&nbsp;flavicornis</em>,&nbsp;<em>Oithona&nbsp;plumifera</em>,&nbsp;and&nbsp;<em>Corycaeus&nbsp;typicus</em>.&nbsp;Examination&nbsp;of&nbsp;341&nbsp;stomachs&nbsp;of&nbsp;<em>A.&nbsp;anthias</em>&nbsp;revealed&nbsp;21&nbsp;prey&nbsp;groups,&nbsp;with&nbsp;Copepoda&nbsp;constituting&nbsp;the&nbsp;primary&nbsp;food&nbsp;source&nbsp;in&nbsp;all&nbsp;seasons&nbsp;(%IRI&nbsp;=&nbsp;56.29–80.47).&nbsp;While&nbsp;copepod&nbsp;dominance&nbsp;was&nbsp;particularly&nbsp;pronounced&nbsp;during&nbsp;winter&nbsp;and&nbsp;summer,&nbsp;the&nbsp;contribution&nbsp;of&nbsp;Ostracoda,&nbsp;Bivalvia,&nbsp;fish&nbsp;prey,&nbsp;and&nbsp;other&nbsp;zooplanktonic&nbsp;groups&nbsp;increased&nbsp;during&nbsp;spring&nbsp;and&nbsp;autumn.&nbsp;Morato&nbsp;index&nbsp;results&nbsp;identified&nbsp;Copepoda&nbsp;as&nbsp;the&nbsp;principal&nbsp;prey&nbsp;group&nbsp;throughout&nbsp;the&nbsp;year.&nbsp;Chesson’s&nbsp;α&nbsp;analysis&nbsp;indicated&nbsp;that&nbsp;copepods&nbsp;were&nbsp;largely&nbsp;consumed&nbsp;according&nbsp;to&nbsp;their&nbsp;environmental&nbsp;availability,&nbsp;whereas&nbsp;certain&nbsp;prey&nbsp;groups&nbsp;were&nbsp;actively&nbsp;selected.</p><p> Overall,&nbsp;<em>A.&nbsp;anthias</em>&nbsp;exhibited&nbsp;a&nbsp;predominantly&nbsp;planktivorous&nbsp;feeding&nbsp;strategy&nbsp;in&nbsp;Sığacık&nbsp;Bay,&nbsp;while&nbsp;demonstrating&nbsp;considerable&nbsp;trophic&nbsp;flexibility&nbsp;in&nbsp;response&nbsp;to&nbsp;seasonal&nbsp;changes&nbsp;in&nbsp;zooplankton&nbsp;composition.</p>

View details