The discovery of individuals of softmouth trout Salmo obtusirostris in the marine environment has been recorded several times in the period from 2015 to the present day in the wider area of the ...Neretva River delta and southern Adriatic coast. Although this phenomenon appears to be happening more frequently along the Adriatic coast, scientific reports regarding family Salmonidae species found in the marine environment are still very rare in the eastern Adriatic, especially for the softmouth trout. The findings reported here represent the first marine records of this endemic freshwater species. An increasing frequency of these findings may indicate that a higher number of individuals are ending up in the coastal environment during heavy storm events or other unusual hydrologic occurrence. Extreme weather conditions have become more frequent in recent years, mainly as a result of climate change and have led to unexpected phenomena and impacts on nature. The long-term effects on fish and community structure of rivers flowing into the sea require further research, as these weather-induced situations can be expected to become more common. Further investigation into the physiological costs and population consequences of these unusual ecological findings is warranted.
Fish otoliths pose increasing interest due to their potential of rendering information about environmental changes, underlined in their non-linear time-dependent biogenic crystal growth. Otoliths are ...acellular, metabolically inert and continuously grow in a complex process which still needs to be understood. In the present work confocal Raman microspectroscopy (CRM) and imaging is employed to investigate the growth pattern in otoliths from Sparus aurata of Mediterranean provenance. CRM signal acquired from otolith sagittal section is exploited to associate it with the periodic growth increments denoted as rings. Raman signal collected from the core to the margins with micrometer spatial resolution invariably revealed characteristic signal of aragonite. Relative intensity variability was observed particularly for the lattice modes, indicating changes in crystalline orientation relative to incident laser. Bands associated with organic fraction were absent in the 90-1840 cm.sup.-1 spectral range. Daily growth rings were further studied using the Raman mapping of main aragonite bands intensities at 1083, 704 and the lattice modes in the 100-350 cm.sup.-1 range. The spectral intensity pattern closely follows the daily growth pattern. Traces of toxic or heavy metals incorporated in biogenic carbonate mineral were spuriously detected in the mapped areas, according to the position and width of the Raman bands of witherite (BaCO.sub.3), strontianite (SrCO.sub.3), along with the main aragonite and trace of its calcite polymorph. Keywords: Confocal Raman micro-spectroscopy, fish otoliths, Raman mapping, growth rings, aragonite.
An outbreak of bluetongue virus serotype 9 in Southern Croatia Listes, E., Croatian Veterinary Inst., Split (Croatia). Regional Veterinary Inst; Bosnic, S., Croatian Veterinary Inst., Zagreb (Croatia); Benic, M., Croatian Veterinary Inst., Zagreb (Croatia) ...
Acta veterinaria Brno,
12/2011, Letnik:
80, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The aim of this study was to provide a description of the first epidemic of bluetongue and the first survey on midges of the genus Culicoides in Croatia. Clinical signs were firstly observed on ...November 2001 in sheep in Konavle, Dubrovnik - Neretva County. During this epizootic the overall sheep morbidity and mortality were 5.2% (95% confidence interval (c.i.), 4.1-6.6%) and 2.29% (95% c.i., 1.6-3.3%), respectively. After the outbreak, 3,318 serum samples of ruminants from 53 villages of the Dubrovnik - Neretva County were examined for bluetongue virus (BTV) antibodies by competitive enzyme-linked immunosorbent assay (cELISA). In forty nine (92.45%, 95% c.i., 82.11-96.92%) of the 53 villages, animals with antibodies against bluetongue virus were found. In particular, a total of 178 cattle (49.86%, 95% c.i., 44.7-55.0%), 174 sheep (13.72%, 95% c.i., 11.9-15.7%) and 270 goats (15.95%, 95% c.i., 14.3-17.8%) were seropositive. Antibodies to bluetongue virus serotype 9 were detected in 212 positive sera by serum neutralization test. The percentage of positive animals decreased from the east to the west suggesting a possible east westward spreading of BTV infection. Fourteen light-trap midge collections from seven different sites were examined. Out of the 4,872 Culicoides spp. collected, 92% (95% c.i., 91.4-92.9%) of them belonged to the species of Obsoletus complex. This study showed for the first time that a pathogenic strain of BTV-9, probably from Montenegro, entered Croatia causing disease and death in local sheep and that C. obsoletus and C. scoticus were likely the major vectors of infection.
Weight-length regressions are presented for 40 fish species caught during the period 1 January 1991–1 January 1995 in the eastern Adriatic (Croatian waters). Samples were collected with beach seine, ...gill and trammel nets. The values of the exponent
b in the weight-length relationship
W =
aL
b
ranged from 2.607–3.512 and the median value was 3.038, whereas 50% of the values ranged between 2.939 and 3.196. The application of these regressions should be limited to the observed length ranges.
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