Temporal and spatial variation in gonadal output of the red gorgonian Paramuricea clavata (Risso, 1826) populations in the Eastern Adriatic Sea

Crvena gorgonija, Paramuricea clavata je dugoživuća vrsta koralja koja ima vrlo važnu ulogu u strukturi i funkcioniranju mediteranskih cirkalitoralnih zajednica. Glavni cilj ovog istraživanja bio je ustanoviti prostornu i vremensku varijabilnost u produktivnosti gonada kod populacija crvene gorgonije u istočnom Jadranu. Uzorkovanje je provedeno na 3 lokacije i u 2 godine (2009 i 2011). Kod ženskih kolonija nije bila prisutna varijabilnost u broju gonada po polipu (fekunditetu), dok se broj gonada u muškim kolonijama razlikovao između godina i pojedinih populacija. Volumen gonada se razlikovao vremenski i prostorno u oba spola, uslijed značajnih razlika u fekunditetu i/ili promjeru gonada. S obzirom na neznačajnu prostornu i vremensku varijabilnost ženskog fekunditeta te utvrđen raspon vrijednosti u populacijama koje nisu bile pod znatnijim recentnim negativnim utjecajem, ta se reproduktivna karakteristika nameće kao osobito pogodan indikator potencijalnih negativnih utjecaja na reprodukciju crvene gorgonije u Jadranskom moru.Red gorgonian Paramuricea clavata is a long-lived coral with important role in the structure and functioning of Mediterranean sublittoral communities. The main goal of this study was to assess the spatial and temporal variation in gonadal output of the red gorgonian populations in the Eastern Adriatic. Sampling was carried out in 3 locations and 2 years (2009 and 2011). There was no variation found in the average number of gonads per polyp (i.e. fecundity) of the female colonies whereas the average number of gonads in male colonies differed between the years and some populations. Temporal and spatial variability was found in the average gonadal volume of both sexes and was caused by significant differences in fecundity and/or gonadal diameter. Taking into consideration a non-significant spatial and temporal variability of female fecundity and the establishment of range of its values for populations that were not recently affected, female fecundity may be proposed as a suitable indicator of potential negative impacts on the reproduction of the red gorgonian in the Adriatic Sea