KONDICIJA ENDEMSKIH MEKOUSNIH PASTRVA SALMOTHYMUS OBTUSIROSTRIS NAKON MRIJESTA

The condition of endemic soft–muzzled trout Salmothymus obtusirostris from the Dalmatian river Žrnovnica was studied. The sampling results of the length–weight relationship in the post–spawning period showed as expected negative allometric growth with a low b–value of 2.26 (W=0.16.L2.26) and also negative relationship between condition factor and standard length (CF =2.775 — 0.051 SL; r = –0.767, p<0.01). Drop in condition occurs between 20 and 27 cm of standard length. These results indicate that the fish from this population partially start spawning in the third year, while most of them spawn from the fourth year on.Istraživali smo kondiciju endemske mekousne pastrve Salmothymus obtusirostris iz dalmatinske rijeke Žrnovnice. Rezultati dužinsko–masenih odnosa u razdoblju nakon mriješćenja pokazuju očekivani negativni alometrijski rast i nisku b vrijednost od 2,26 (W=0,16.L2,26), kao i negativni odnos između faktora kondicije i standardne dužine (CF = 2,775 — 0,051 SL; r = –0,767, p<0,01). Pad kondicije zamjećuje se između dvadesetog i dvadeset i sedmog centimetra standardne dužine. Ovi rezultati upućuju na djelomično mriješćenje riba ove populacije u trećoj godini života, a većina se njih mrijesti tek u četvrtoj godini života i poslije

KONDICIJA ENDEMSKIH MEKOUSNIH PASTRVA SALMOTHYMUS OBTUSIROSTRIS NAKON MRIJESTA

The condition of endemic soft–muzzled trout Salmothymus obtusirostris from the Dalmatian river Žrnovnica was studied. The sampling results of the length–weight relationship in the post–spawning period showed as expected negative allometric growth with a low b–value of 2.26 (W=0.16.L2.26) and also negative relationship between condition factor and standard length (CF =2.775 — 0.051 SL; r = –0.767, p<0.01). Drop in condition occurs between 20 and 27 cm of standard length. These results indicate that the fish from this population partially start spawning in the third year, while most of them spawn from the fourth year on.Istraživali smo kondiciju endemske mekousne pastrve Salmothymus obtusirostris iz dalmatinske rijeke Žrnovnice. Rezultati dužinsko–masenih odnosa u razdoblju nakon mriješćenja pokazuju očekivani negativni alometrijski rast i nisku b vrijednost od 2,26 (W=0,16.L2,26), kao i negativni odnos između faktora kondicije i standardne dužine (CF = 2,775 — 0,051 SL; r = –0,767, p<0,01). Pad kondicije zamjećuje se između dvadesetog i dvadeset i sedmog centimetra standardne dužine. Ovi rezultati upućuju na djelomično mriješćenje riba ove populacije u trećoj godini života, a većina se njih mrijesti tek u četvrtoj godini života i poslije

THE POSSIBILITIES OF SMALL FAMILY FISH FARMS MANAGEMENT

Tranzicijske promjene u Srednjoj Europi bitno su utjecale na ukupnu poljoprivrednu proizvodnju, pa tako i na slatkovodnu akvakulturu. U mnogim je zemljama proizvodnja smanjena na samo trećinu, a znatan broj velikih ribnjačarstava smanjio je svoje proizvodne površine. S druge strane, važnu ulogu odigrao je i rastući senzibilitet za probleme okoliša pridonijevši popularizaciji eksploatacije kopnenih voda za športski ribolov, šport i rekreaciju. Navedene su promjene utjecale i na neke male obiteljske farme koje do sada nisu bile angažirane u ribarstvu, da mu se posvete na drukčiji način. Stoga ovaj rad razmatra mogućnosti poslovanja malih obiteljskih ribnjaka u novim uvjetima. Posebno se analizira njihov rad kao objekata za komercijalni športski ribolov, te za ciprinidnu i salmonidnu akvakulturu.The transitional changes in Central Europe significantly influenced the entire agriculutral production, Croatian fresh-water aquaculture included. The production in many countries fell down to only one third, while many bih fish farms reduced their production acreage. On the other hand, more alert sensitivity to ecological problems made water exploitation for angling, sport and recreation purposes, quite popular. Some small farms that have not been into fisheries yet, were influenced to change their business policy and take part in new viewpoints of fisheries. The possibilities of small family fish farm management in new conditions in particular as regard to commercial sport fisheries, to cyprinid as well as salmonid aquaculture are therefore discussed in this paper

Comparison of non-destructive techniques and conventionally used spectrometric techniques for determination of elements in plant samples (coniferous leaves)

Conventionally used spectrometric techniques of inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma optical emission spectrometry (ICP-MS) usually involve time-consuming sample preparation procedure of a sample dissolution which requires the usage of aggressive and toxic chemicals. The need for suitable and sustainable analytical methods for direct multi-elemental analysis of plant samples has been increased in recent years. Spectrometric techniques for direct sample analysis, instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF) have been applied in environmental studies and various fields of screening tests. Nevertheless, these techniques are not commonly used for plant sample analysis and their performances need to be evaluated. This research aimed to assess how reliable non-destructive techniques are in the determination of elements in plants compared to conventionally used spectrometric techniques. A total of 49 plant samples of four conifer species (Pinus nigra, Abies alba, Taxus baccata and Larix decidua) were measured using two conventionally applied (ICP-MS, ICP-OES) and two non-destructive techniques (wavelength dispersive XRF (WD-XRF), INAA). The comparison was performed by investigation of relative ratios of concentrations and by correlation analysis. Moreover, precision of the techniques was examined and compared. The quality control included analysis of NIST pine needles certified reference material (1575a) using all examined techniques. Our results suggest that additional analytical and quality control steps are necessary for reaching the highest accuracy of multi-elemental analysis

Urban deciduous tree leaves as biomonitors of trace element (As, V and Cd) atmospheric pollution in Belgrade, Serbia

Leaves of common deciduous trees: horse chestnut (Aesculus hippocastanum) and linden (Tilia spp.) from three parks within the urban area of Belgrade were studied as biomonitors of trace element (As, V, and Cd) atmospheric pollution. The May–September trace element accumulation in the leaves, and their temporal trends, were assayed in a multi-year period (2002–2006). Significant accumulation in the leaves was evident for As and V, but not so regularly for Cd. Slightly decreasing temporal trends of V and As ac-cumulated in the leaf tissues were observed over the years. During the time span, the concentrations of Cd remained approximately on the same level, except in May 2002 and September 2005, when a rapid increase was observed. The May–September accumulations of As and V were higher in horse chestnut than in linden, although both may be used as biomonitors for these elements, and optionally for Cd in conditions of its high atmospheric loadings

RESEARCH METHODOLOGY ON NATURAL NUTRITION OF FRESH-WATER FISH

Ovaj rad daje cjelokupan prikaz metologije istraživanja prirodne prehrane riba. Podaci o prehrani slatkovodnih riba, napose gospodarstveno manje važnih vrsta, vrlo su oskudni. Pregledom literature ustanovljeno je da se autori služe različitim pristupima i metodama u procjeni parametara. U ovom se radu prikazuju najčešće primjenjivani parametri kvalitativne i kvantitativne analize. Kvalitativna analiza sastava hrane iznosi se kao ukupan popis taksona (uglavnom vrsta i rodova) koje je moguće determinirati, dok kvantitativna analiza obuhvaća procjenu pojedinih hranidbenih kategorija s pomoću hranidbenih indeksa i koeficijenata. Biološka identifikacija i numerička obrada dobivenih podataka može imati niz nedostataka kao što je efekt izbacivanja plijena ili stupanj probave plijena. Analiza tih faktora preteča je detaljne statističke obrade podataka sa svrhom da se obuhvati i prostorna distribucija pojedinih kategorijia plijena. U raspravi se ističe važnost tih podataka kako pri definiranju hranidbenih zahtjeva potencijalnih vrsta riba za uzgoj, tako i pri stvaranju novih spoznaja o nekom vodenom ekosustavu.This paper offers the entire review on the research methodology in natural nutrition of fresh-water fish. The data on fresh-water fish nutrition, particularly on fish of lower economic value, is inadequate. Reviewing the literature on assesment of nutritional parameters, the authors obviously use differenet approaches and methods. This paper is about most frequently used parameteres in qualitative and quantitative analysis. The qualitative analysis of food structure is the overall list of determinable taxa (mostlyu species and genera). The quantitative analysis comprises the assessment of particular nutritional categories by nutritional indices and coefficients. Bio-identification and numeric data processing can have numerous drawbacsk such as effect of regurgitation or the degree of digestion of the prey. The analyses of those effects proceed through statistical data processing in order to include spatial distribution of certain prey categories as well. The importance of this data is to determine the nutritional needs of potential species for culture as well as to come up with new insights on a particular aquatic ecosystem

THE USE OF MOLECULAR METHODS IN FISHERIES

Velika različitost među ribljim populacijama i vrstama, od kojih neke nisu do kraja definirane (npr. vrste roda Cobitis), te negativni čovjekov utjecaj zbog prevelike eksploatacije, neadekvatnih poribljavanja, te promjena prirodnih sredina osigurali su činjenicu da su ribe postale središtem brojnih molekularno –bioloških istraživanja. Ovdje dajemo pregled nekih češće primjenjivanih tehnika u razlikovanju ribljih populacija, osvrćemo se na njihove prednosti i nedostatke. U uzgoju riba daje se uvid u problem redukcije genetske različitosti, kako u slatkovodnom ribarstvu (npr. šarana, Cyprinus carpio), tako i u marikulturi (npr. lubina, Dicentrarchus labrax).The existence of high diversity between fish populations and species, among which some are not completely defined (for instance species of genus Cobitis), as well as negative human influence through overexploitation, non adequate fish stockings and changes of natural habitats, both ensured the fact that fish entered into the focus of many molecular biological investigations. In this paper has been given the review of the most used techniques in the differentiation of fish populations, including their advantages and weaknesses. The problem of the reduction of genetic diversity in freshwater (for instance common carp, Cyprinus carpio) and marine (for instance seabass, Dicentrarchus labrax) aquaculture is also discussed

RESEARCH METHODOLOGY ON NATURAL NUTRITION OF FRESH-WATER FISH

Ovaj rad daje cjelokupan prikaz metologije istraživanja prirodne prehrane riba. Podaci o prehrani slatkovodnih riba, napose gospodarstveno manje važnih vrsta, vrlo su oskudni. Pregledom literature ustanovljeno je da se autori služe različitim pristupima i metodama u procjeni parametara. U ovom se radu prikazuju najčešće primjenjivani parametri kvalitativne i kvantitativne analize. Kvalitativna analiza sastava hrane iznosi se kao ukupan popis taksona (uglavnom vrsta i rodova) koje je moguće determinirati, dok kvantitativna analiza obuhvaća procjenu pojedinih hranidbenih kategorija s pomoću hranidbenih indeksa i koeficijenata. Biološka identifikacija i numerička obrada dobivenih podataka može imati niz nedostataka kao što je efekt izbacivanja plijena ili stupanj probave plijena. Analiza tih faktora preteča je detaljne statističke obrade podataka sa svrhom da se obuhvati i prostorna distribucija pojedinih kategorijia plijena. U raspravi se ističe važnost tih podataka kako pri definiranju hranidbenih zahtjeva potencijalnih vrsta riba za uzgoj, tako i pri stvaranju novih spoznaja o nekom vodenom ekosustavu.This paper offers the entire review on the research methodology in natural nutrition of fresh-water fish. The data on fresh-water fish nutrition, particularly on fish of lower economic value, is inadequate. Reviewing the literature on assesment of nutritional parameters, the authors obviously use differenet approaches and methods. This paper is about most frequently used parameteres in qualitative and quantitative analysis. The qualitative analysis of food structure is the overall list of determinable taxa (mostlyu species and genera). The quantitative analysis comprises the assessment of particular nutritional categories by nutritional indices and coefficients. Bio-identification and numeric data processing can have numerous drawbacsk such as effect of regurgitation or the degree of digestion of the prey. The analyses of those effects proceed through statistical data processing in order to include spatial distribution of certain prey categories as well. The importance of this data is to determine the nutritional needs of potential species for culture as well as to come up with new insights on a particular aquatic ecosystem

Natural diet of barbel Barbus peloponnesius (Valenciennes, 1842) from the Sava river

Elektroribolovom, od lipnja do listopada 2001. g., lovljena je mrena (Barbus peloponnesius) iz rijeke Save na lokaciji Medsave. Ciljevi ovog istraživanja bili su dobiti podatke o hranidbi ove vrste riba u prirodnim uvjetima, utvrditi sastav sadržaja probavila i njegov odnos spram raspoloživih biljnih i životinjskih svojti istraživanog područja. U proljetnom razdoblju, strukturu hranidbe mrene čine Chironomidae, Oligochaeta i Cladocera, u ljetnom razdoblju Chironomidae, Ephemeroptera, Trichoptera s kombinacijom Bacillariophyceae i Chlorophyceae. U jesenskom razdoblju glavna hrana su ličinke Insecta i Bacillariophyceae. Hranidba nižih dužinskih kategorija mrene temelji se na životinjskim i biljnim komponentama, dok u hrani jedinki većih dužina prevladava životinjski materijal. Selektivnost hranidbe s raspoloživim svojtama u okolini, različita je u pojedinim razdobljima. Pozitivnu selekciju u lipnju pokazivale su prema Xantophyceae i makroavertebrata, u srpnju prema Chlorophyceae, Bacillariophyceae i makroavertebrata, a u listopadu prema Bacillariophyceae i makroavertebrata.The barbel population (Barbus peloponnesius) was studied in the Sava River at Medsave from July to October 2001. The main objective of the study was to obtain data on diet composition of this species in natural biotopes with relation to food availability in the river. In the spring, the dominant food items of barbel were Chironomidae, Oligochaeta and Cladocera. In the summer, they preferred Chironomidae, Ephemeroptera, and Trichoptera with a combination of plant foods Bacillariophyceae and Chlorophyceae. The main foods of this species in the autumn were larvae of Insecta and Bacillariophyceae. Smaller barbel preferred animal prey and less plant items, while larger sizes of this species preferred only animal prey. Diet selectivity with relation to food availability in the environment was diverse in various investigated period. Positive selectivity in June was found for Xantophyceae and makroavertebrates, in July for Chlorophyceae, Bacillariophyceae and macroinvertebrates and in October for Bacillariophyceae and macroinvertebrates

THE USE OF MOLECULAR METHODS IN FISHERIES

Velika različitost među ribljim populacijama i vrstama, od kojih neke nisu do kraja definirane (npr. vrste roda Cobitis), te negativni čovjekov utjecaj zbog prevelike eksploatacije, neadekvatnih poribljavanja, te promjena prirodnih sredina osigurali su činjenicu da su ribe postale središtem brojnih molekularno –bioloških istraživanja. Ovdje dajemo pregled nekih češće primjenjivanih tehnika u razlikovanju ribljih populacija, osvrćemo se na njihove prednosti i nedostatke. U uzgoju riba daje se uvid u problem redukcije genetske različitosti, kako u slatkovodnom ribarstvu (npr. šarana, Cyprinus carpio), tako i u marikulturi (npr. lubina, Dicentrarchus labrax).The existence of high diversity between fish populations and species, among which some are not completely defined (for instance species of genus Cobitis), as well as negative human influence through overexploitation, non adequate fish stockings and changes of natural habitats, both ensured the fact that fish entered into the focus of many molecular biological investigations. In this paper has been given the review of the most used techniques in the differentiation of fish populations, including their advantages and weaknesses. The problem of the reduction of genetic diversity in freshwater (for instance common carp, Cyprinus carpio) and marine (for instance seabass, Dicentrarchus labrax) aquaculture is also discussed