Acta Adriatica, Vol. 63 No. 2, 2022.
Original scientific paper
https://doi.org/10.32582/aa.63.2.3
Ingression of the hydromedusa Neotima lucullana (delle chiaje, 1822) into the ecosystem of the Neretva river estuary (south-eastern Adriatic, Croatia
Davor Lučić
; University of Dubrovnik, Institute for Marine and Coastal Research, 20000 Dubrovnik, Croatia
Ivona Onofri
; University of Dubrovnik, Institute for Marine and Coastal Research, 20000 Dubrovnik, Croatia
Rade Garić
; University of Dubrovnik, Institute for Marine and Coastal Research, 20000 Dubrovnik, Croatia
Ivana Violić
; University of Dubrovnik, Department of Applied Ecology, 20000 Dubrovnik, Croatia
Mijo Vranješ
; University of Split, Faculty of Civil Engineering, Architecture and Geodesy, 21000 Split, Croatia
Barbara Gangai Zovko
; University of Dubrovnik, Institute for Marine and Coastal Research, 20000 Dubrovnik, Croatia
Jure Jurinović
; Opuzen 20355, Podgradina 15, Croatia
Jakica Njire
; University of Dubrovnik, Institute for Marine and Coastal Research, 20000 Dubrovnik, Croatia
Marijana Hure
; University of Dubrovnik, Institute for Marine and Coastal Research, 20000 Dubrovnik, Croatia
Abstract
Hydromedusa Neotima lucullana is an endemic species of the Mediterranean Sea. In this study
we document the first numerous and permanent occurrence of N. lucullana in the estuary of the
Neretva River, an unusual habitat for this typical marine species. We provide COI barcode sequence
of this species, which is also first genetic sequence ever published of N. lucullana. Weekly data on the
occurrence and abundance of N. lucullana were obtained from reports and records of autonomous
divers and local fishermen in the area from Opuzen to Metković from mid-June to the end of October
2021. The individuals were always located in the layer above the bottom with salinity between 35.2
and 38.2. The diameters of the jellyfish bells ranged from 15 mm to 72 mm, most of them between
40 mm and 58 mm. Differential development of the gonads was observed in all specimens larger
than 25 mm. In mid-June, the specimens were common but solitary. A week later, the jellyfish
were more frequent and in smaller aggregations. From late June to mid-September, the jellyfish
were constantly observed in larger aggregations. Toward the autumn, the number of individuals
gradually decreased, and by the last week of October, only single individuals were observed. Our
results indicate significant changes in the ecosystem of the Neretva estuary and confirm the observed
composition of zooplankton communities dominated by marine species in summer and autumn.
Keywords
jellyfish; Eirenidae; zooplankton; karstic estuary ecosystem; Mediterranean Sea
Hrčak ID:
289601
URI
Publication date:
30.12.2022.
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