The recruitment of leaping grey mullet, Liza saliens juveniles in the Neretva River estuary (middle eastern Adriatic Sea, Croatia) started in July, was highest in August, decreased in September, and ...was unobserved later. The juveniles firstly occupied mouths of rivers and channels and then started migrating to more freshwater habitats. By feeding investigation, the harpacticoid copepods were the dominant prey in the stomachs of L. saliens juveniles during the period from August to December and nematodes replaced those as the dominant prey from January to April. Plant material in the stomachs started to appear at 24 mm of standard length, and was common prey in fish larger than 26 mm. In comparison with other Adriatic mullet's species, the leaping grey mullet juveniles first started to recruit during July and August, while other grey mullet species appeared later (in September) in the Neretva River estuary. Such intraspecies spawning and recruitment segregation together with the optimal quantity and quality of available and preferable prey could provide an explanation for the recent success and propagation of this species in this area.Original Abstract: Novacenje mladji cipla dugasa, Liza saliens na podrucju estuarija rijeke Neretve pocinje u srpnju, najvece je u kolovozu, smanjuje se u rujnu, nakon cega nije zabiljezeno. Mladj se najprije pojavljuje na uscima rijeka i kanala, a zatim pocinje migrirati prema vodama nize slanosti. U prehrani mladji cipla dugasa od kolovoza do prosinca su dominirali harpatikoidni kopepodi, a od sijecnja do travnja oblici. Biljni materijal se pocinje pojavljivati u probavilima jedinki najmanje ukupne duzine 24 mm, a uobicajen je u probavilima riba vecih od 26 mm. Usporedjujuci s ostalim vrstama cipala u podrucju estuarija rijeke Neretve koje se mrijeste u ljetno-jesenskom razdoblju, dugas se pocinje novaciti prvi, tijekom srpnja i kolovoza, dok se ostale vrste pojavljuju u rujnu. Ovo ranije mrijestenje i novacenje mladji bez nazocnosti drugih vrsta cipala, tijekom razdoblja optimalnog sastava i brojnosti hrane, moze biti jedan od razloga recentne propagacije cipla dugasa na podrucju estuarija Neretve.
The present paper describes the recruitment and food composition of thin-lipped grey mullet, Liza ramada (Risso, 1826) juveniles in the estuary of the Neretva River in the southeastern Adriatic. ...Thin-lipped mullet appeared in the Port of Ploce in February. The relationships between total length, standard length, and weight showed a remarkably good fit to the expected allometric model, with b=3 for total length. Twelve different animal food categories were identified. The greatest diversity was recorded in April at the Port of Ploce when 10 categories were present. In addition, six diatom taxa were noted. Harpacticoid copepods were the most common prey (39%) in these samples, followed by insects (32%) and cladocerans (12%). All other prey accounted for less than 4%. Insects represented 99% of prey in the stomachs of specimens sampled from the freshwater Crna Rijeka River. Thin-lipped mullet juveniles were not found on sandy beaches or natural bays around the port. It thus appears that juveniles find the port area to be a habitat with the favorable characteristics of a brackish water nursery: of predators, lower salinity, and high food availability. These all promote better survival and recruitment in this area of the Croatian Adriatic.Original Abstract: U ovom radu opisuju se novacenje i sastav hrane mladji cipla balavca Liza ramada na uscu rijeke Neretve u jugoistocnom Jadranu. Cipal balavac se pojavljuje u luci Ploce tijekom veljace. Odnosi izmedju ukupne duzine, standardne duzine i mase pokazuju izuzetno dobro poklapanje s ocekivanim alometrijskim modelom, za vrijednost alometrijskog koeficijenta b=3 za ukupnu duzinu. Odredjeno je dvanaest razlicitih kategorija hrane. Najveca raznolikost, 10 skupina plijena, je utvrdjena u travnju u luci Ploce. Dodatno je utvrdjeno 6 taksonomskih kategorija alga kremenjasica. Harpaktikoidni veslonosci su najcesci plijen (39%) mladji cipla balavca, zatim slijede kukci (32%) i rasljoticalci (12%). Na sav ostali plijen otpada manje od 4%. Kukci predstavljaju 99% plijena utvrdjenog u probavilima jedinki prikupljenih iz Crne rijeke. Mladj cipla balavca nije utvrdjena na pjescanim plazama i zaljevima sireg podrucja usca Neretve. Smatra se da je brojnost mladji cipla balavca u luci Ploce u svezi s povoljnim uvjetima stanista kao sto su: manji broj predatora, niza slanost i veca kolicina dostupne hrane. Sve navedeno pogoduje uspjesnijem novacenju cipla balavca u ovom dijelu hrvatskog Jadrana.
Phytoplankton in the karstic pools of Croatian islands has not been investigated in recent times. This paper describes phytoplankton and environmental conditions in three karstic pools on Dugi Otok ...island (Dalmatia). The pools are small (ca 20 m super(2)) and shallow (max. depth 2 m), with Charophytes and vascular plants covering the bottoms. Eighty-five taxa of net phytoplankton were recorded. These included 22 Cyanobacteria, 14 Chlorophyceae, 17 Charophyceae (Zygnematales), 15 Euglenophyceae, and 17 Bacillariophyceae. Low species richness is owed to the predominance of Cyanobacteria. Despite their similar physicochemical regimes, the pools had different phytoplankton communities. The data presented here contribute baseline information concerning biological diversity, essential for evaluation of environmental changes in the future. Conservation of karstic pools is one way to preserve the overall biodiversity of karstic islands.
This paper is based on the main results of an analysis of spontaneous flora and vegetation on the small islet of Vrnik (0.281 km2), on which there are some abandoned limestone quarries, on the ...eastern Adriatic coast. The investigations were carried out from 2014 to 2016. Altogether, 251 vascular plant taxa (species and infraspecific units) were recorded on the islet. A total of 11 plant associations, one subassocation and two stands within 10 vegetation classes were identified. Due to high anthropogenic influences during the last centuries, quarrying in particular, the islet investigated showed a relatively low variety of vascular plant taxa. In addition, clear signs of fragmentation of the forest vegetation were observed.
Cilj rada bio je doprinijeti poznavanju mikrofitobentosa u Jadranskom moru istražujući po prvi put bentoske dijatomejske zajednice u Neumskom zaljevu u Bosni i Hercegovini. Bentoske dijatomeje su ...određene na jednoj postaji u poluzatvorenom oligotrofnom Neumskom zaljevu 2010. i 2011. Sakupljeno je 24 uzoraka na dubinama 0,5 i 8 m, a analizirani su s pomoću svjetlosnog i skenirajućeg elektronskog mikroskopa. U uzorcima je utvrđeno 425 penatnih i 58 centričnih svojti (vrsta i nižih taksonomskih kategorija) dijatomeja unutar 60 porodica i 115 rodova. Najveći broj svojti nađen je unutar sljedećih rodova: Mastogloia (46 svojti), Navicula (36), Diploneis (35), Nitzschia (34), Amphora (31), Cocconeis (27), Achnanthes (14), Halamphora (12), Lyrella (11) te Surirella i Licmophora (svaki po 10 svojti). Najčešće svojte su Amphora bigibba var. interrupta i Cocconeis scutellum s 87,5% učestalosti u ukupnom broju uzoraka. Utvrđene su 142 sporadične svojte (utvrđene u samo jednom uzorku). Iako je broj svojti relativno visok, nije utvrđena pravilnost u njihovoj vremenskoj raspodjeli. Radi preciznijeg utvrđivanja sezonskih i prostornih promjena strukture epilitskih dijatomejskih zajednica, potrebni su detaljniji kvalitativni i kvantitativni podaci.
In Europe, Myriophyllum heterophyllum Michx. (Haloragaceae) has had the status of invasive species in freshwater ecosystems since 2012. During phytosociological research in the Neretva River Delta in ...July 2016, we noted a high coverage of species Myriophyllum heterophyllum within vegetation of rooted leaf-floating macrophytes of the Nymphaeion albae Oberd. 1957 alliance (the order Potamogetonetalia Koch 1926). In this paper, alongside the finding of the new locality with M. heterophyllum in Croatia, its phytosociology is reported.
Chouardia lakusicii (ili) Speta, a very rare species in the Croatian flora, was discovered during a study of the karstic flora on the Torac and Ivanova lazina mountains above the villages of Majkovi ...and Mravinjac, northeast of the village of Slano (Southern Dalmatia, Croatia). Previously, this species in Croatia had been only described in one locality, north of Mt. Biokovo (the Zabiokovlje area). The present specimens were recorded at elevations of 720 780 m, within open rocky limestone and in the crevices in limestone blocks. The populations showed good viability. According to the International Union for Conservation of Nature methods for threat assessment, we propose that Ch. lakusicii should be included in the category of vulnerable taxa (VU; criteria A3C, B2A, b (ii, v)) and included in the national red list.
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