341 research outputs found
A sea of worms: polychaete checklist of the Adriatic Sea
No full textMikac, Barbara (2015): A sea of worms: polychaete checklist of the Adriatic Sea. Zootaxa 3943 (1): 1-172, DOI: 10.11646/zootaxa.3943.1.
Ta simpatična crvolika čudovišta s morskog dna
No full textTA SIMPATIČNA CRVOLIKA ČUDOVIŠTA S MORSKOG DNA TKO SU TA CRVOLIKA MORSKA BIĆA Mnogočetinaši (Polychaeta) su crvoliki, uglavnom morski beskralješnjaci, široko rasprostranjeni u svim morskim staništima, od zone plime i oseke pa sve do najvećih dubina. Njihovo mekano segmentirano tijelo uobičajeno je podijeljeno na glavu, stražnji i srednji člankoviti dio. Svaki članak ima par nožica, zvanih bataljice, iz kojih strše četine – dlačice – različitog oblika, broja i veličine, po kojima su mnogočetinaši i dobili ime (grč. poly – mnogo, chaete – četine). Izgled bataljica može varirati od onih koje izgledaju poput vesla za bolje plivanje, do lopatica koje služe za ukopavanje u sediment. Pojedine vrste imaju tvrde četine oblika harpuna, koje ponekad, kao kod jadranskog vatrenog crva, mogu biti čak i otrovne. Ima među njima patuljaka manjih od jednog milimetra, ali i crvolikih morskih čudovišta veličine do 4 metra. A kako se kreću? Ima tu svega, od brzih atleta, sporih puzača, do pričvršćenih i nepokretnih vrsta. Pokretne vrste mnogočetinaša pužu po sedimentu, stijenama i algama ili ruju u morskom dnu, nepokretne vrste pričvršćene su za morsko dno i zaštićene kožnatom ili vapnenom cijevi koju nikada ne napuštaju, a ima i planktonskih vrsta. Nepokretne vrste koje žive u cijevima, uobičajeno na prednjem kraju tijela imaju šareni vijenac škrga pomoću kojih dišu i hvataju čestice hrane iz morske vode. Iznenađujuća je prehrambena raznolikost tih organizama: ima među njima umiljatih biljojeda koji brste alge i morske cvjetnice, opasnih predatora koji aktivno love plijen, strvinara koji se hrane lešinama morskih organizama, detritofaga koji skupljaju raspadnutu organsku tvar iz sedimenta i filtratora koji iz morske vode procjeđuju plankton i organsku tvar. Mnogočetinaši igraju važnu ulogu u hranidbenim lancima u moru. Često predstavljaju dominantnu skupinu organizama u zajednicama morskog dna, a na pjeskovitim i muljevitim dnima tvore guste populacije koje znatno utječu na karakteristike sedimenta. Mnogočetinaši su poput morskih gujavica. Bušenje morskog dna koje uzrokuju ovi crvi utječe na transport čestica i preraspored organske tvari u sedimentu, poboljšava protok kisika i ugljičnog dioksida, prozračenost i eliminaciju izlučevina iz sedimenta. Stoga ih možemo nazvati i čistačima mora. Neke vrste mnogočetinaša vrlo su osjetljive na promjene u okolišu, pokazatelji su stanja pridnenih zajednica i kvalitete mora te se njima često koriste kao indikatorima zagađenja. Stoga je njihovo istraživanje od iznimne važnosti kako u temeljnim biološkim znanostima (sistematika, taksonomija) tako i u primijenjenim istraživanjima okoliša. Danas je u svijetu poznato oko 9000 vrsta mnogočetinaša (Rouse & Pleijel, 2001), ali pretpostavlja se da svjetska mora i oceani kriju još mnogo vrsta takvih organizama koje tek trebaju biti otkrivene. A u Jadranu? Jedno more crva! Čak 764 vrste mnogočetinaša iz 360 rodova i 62 porodice – 68% od poznate faune mnogočetinaša Sredozemlja – otkriveno je do sada u Jadranskom moru (Mikac, 2015). Od toga se čak 29 vrsta smatra alohtonim (alien) vrstama u Sredozemnom moru. Zbirka morskih mnogočetinaša Prirodoslovnog muzeja Rijeka sadrži 120 vrsta mnogočetinaša s oko 610 primjeraka. Predmeti su porijeklom uglavnom iz stare zbirke Mađarske biološke postaje i prikupljeni terenskim istraživanjima. U zadnjih nekoliko godina morska biologinja Barbara Mikac, specijalistica za mnogočetinaše, trajno je pohranila novoopisane vrste mnogočetinaša za Jadran i nove za svjetsku znanost u zbirci Prirodoslovnog muzeja Rijeka. Novim opisima vrsta, holotipovima i paratipovima, vrijednost riječke zbirke izuzetno raste, kao i interes
Posidonija (Posidonia oceanica)
No full textPosidonija (Posidonia oceanica), biljka iz skupine morskih cvjetnica, u narodu poznata kao morska trava, porost, lazina ili voga
Three years seasonal dynamics of the northern Adriatic soft-bottom Polychaete assemblages
No full textAlthough the taxonomic composition of the northern Adriatic soft-bottom Polychaete assemblages is well explored, very little is known about their annual dynamics. Polychaetes were investigated seasonally from March 2003 to December 2006 on three offshore stations in the communities of coastal detritic and muddy coastal detritic bottoms. Sediment samples were collected with 0,1 m2 Van Veen grab and sieved through 2 mm and 1 mm mesh size consequently. Preliminary results of the analyses of 2 mm samples are given. 7295 Polychaetes were examined and 141 species belonging to 36 families were identified. This number represents 20% of the known Adriatic Polychaete fauna to date. Comparison with previous investigations indicates relatively rich Polychaete fauna in the research area. Seasonal fluctuation of abundance was different on three stations and didn’t show periodical pattern but was influenced by the population dynamics of characteristic and dominant species. Increase and decrease of abundance was not closely followed by the growth and reduction of species richness. The most abundant species, mutual for three stations, Notomastus latericeus, Owenia fusiformis and Myriochele oculata are characteristic species of detritic and muddy detritic bottoms. Analysis of population dynamics of species Owenia fusiformis and Notomastus latericeus revealed different pattern than in previous research. Reproductive features of these cosmopolitan species seem to be peculiar to certain population rather then the species itself and depend on different environmental conditions. Low seasonal alterations of structure and dynamics of Polychaete assemblages are consistent with the stable environmental conditions during research period
Echinodermata in the littoral area of Mljet National Park
No full textBackground and Purpose: Complete inventarization of the marine flora and fauna inhabiting Mljet National Park and mapping of benthic communities, have still not been made 35 years after the National Park was established. Due to that fact, the goal of this survey was to explore the echinofauna in the coastal area of Mljet National Park and to make a check-list of the species inhabiting it. Materials and Methods: Fifty-nine stations in the littoral area of Mljet Island were explored during the 1995-1998 period. Fifty-five stations were explored by SCUBA-diving, from which thirty-nine stations along the south-western and north-western coast of Mljet National Park and Mljet island and sixteen stations in Mljet Lakes. Samples from one station were collected by the trawl. Samples from old trammel bottom nets were explored at three stations.
Results: Fourteen benthic communities were registered in supralittoral, mediolittoral, infralittoral and circalittoral zones. 43 echinoderm species were found, from which 1 Crinoidea, 8 Holothuroidea, 13 Asteroidea, 10 Ophiuroidea and 11 Echinoidea species. Spatial distribution of echinoderms in the area explored depended mostly on the type of the bottom, where certain benthic communities developed. Twenty-eight species were found on rocky bottom while thirty-eight species were found on sandy, detritic and muddy bottoms. The richest communities were Posidonia oceanica meadows (27 species) and community of photophilic algae (24 species).
Conclusion: Forty-three species found in the explored area represent about 42% of the Adriatic Sea echinofauna known at present (101 species). Taking into consideration that most of the stations were explored only by SCUBA diving method up to the depth of 40 m, we can consider Mljet National Park as an area rich in echinoderms species
The role of environmental NGOs in public awareness raising and protection of endangered species (step toward the community based conservation)
No full textImpacts of different kinds of harbour pollution of the city of Rovinj (Croatia, northern Adriatic Sea) on polychaete fauna
No full textFaunal and biogeographic analysis of Syllidae (Polychaeta) from Rovinj (Croatia, northern Adriatic Sea)
No full textThe study of hard-bottom Syllidae (Polychaeta) of the Rovinj area provides an updated measure of syllid species diversity in the northern Adriatic Sea. Faunal research in the coldest Mediterranean sectors may also help to address possible ecological and biogeographical consequences arising from climate change. Thirty-nine species were found, of which 13 are new for the northern Adriatic, increasing the species recorded from the area from 53 to 66. Some newly recorded species are dominant and typical of warmer areas. The lack of previous taxonomic updates is responsible for the high number of new findings. However, the northern Adriatic Sea is possibly undergoing long-term changes, with modifications of diversity due to the establishment of warm-water species. Syllid fauna of Sveti Ivan Island and its bioclimatic affinity are, in fact, unexpectedly more similar to the ones of some southern Mediterranean areas than to those traditionally reported for the northern Adriatic
Two new species of Pista Malmgren, 1866 (Polychaeta: Terebellidae) from the Adriatic Sea (Mediterranean)
No full textTwo new species of Pista were collected in 2008 and 2010 from the muddy sand in the Northern Adriatic Sea (Mediterranean).
They were initially identified as Pista cf. lornensis (Pearson, 1969) however this seemed unlikely given that this species was
described from Loch Linnhe, on the north west coast of Scotland. Examination of the material in detail revealed two undescribed
species. Pista sp.n. (Rovinj city harbor, 7m, 30.09.2010.) is characterised by branchial filaments arranged in separate tiers from a
main stalk, lateral lobes continue mid ventrally, and anterior notopodia much smaller than subsequent ones. Pista sp.n. (offshore
station 13NM off the western coast of Istria, 31m, 05.12.2008.) has branchial filaments arranged in a spiral from the main stalk,
with 1st pair of notopodia very small with few small chaetae, and 2nd also small, subsequent notopodia with swollen glandular
bases, lower lip forms a ridged lobe and the shape and arrangement of lateral lobes on segments 2, 3 and 4 differs from Pista
sp.n. (Rovinj city harbor, 7m, 30.09.2010.) .These two new species are compared to other species described from the region, but
a complete revision of the genus is urgently needed
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