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1

Dependence of egg diameter on the size and age of cultivated female lake trout (Salmo trutta m. lacustris L.)

100%
Bartel R., Falowska B., Bieniarz K., Epler P.
Archives of Polish Fisheries
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2005
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tom 13
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nr 1
The aim of this study was to determine the impact of the size and age of cultivated female lake trout on the size of their eggs. The material was collected from 1995 to 1999 at the Olszówka Fish Farm in southern Poland. Eggs were obtained from 310 trout females with a total length range of 30-53 cm (fish aged three to seven years). Following the hardening phase, the maximum and minimum diameters of the eggs were measured and the water volume (calculated based on water displacement) of thirty eggs was determined. The mean egg diameter ranged from 4.08 to 5.85 mm. The variance of egg size within age groups was not large, and the coefficient of variation (V, %) ranged from 2.64 to 6.91. The results indicate that the egg size of lake trout cultivated in ponds was significantly dependent on the size of the females and to a lesser degree on their age.
2
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Age, growth rate, and otolith growth of polar cod (Boreogadus saida) in two fjords of Svalbard, Kongsfjorden and Rijpfjorden

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Fey D. P., Weslawski J. M.
Oceanologia
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2017
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tom 59
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nr 4
This work presents biological information for polar cod (Boreogadus saida) collected with a Campelen 1800 shrimp bottom trawl in Kongsfjorden (two stations located in the inner part of the fjord adjacent to the glacier) and Rijpfjorden (one station at the entrance to the fjord) in September and October 2013. The otolith-based ages of polar cod collected in Kongsfjorden (6.1–24 cm total length TL; n = 813) ranged from 0 to 4 years. The growth rate was relatively constant at approximately 4.7 cm year−1 between years 1 and 4, which indicates that growth was fast in the glacier area. The ages of polar cod collected in Rijpfjorden (8.6–15.9 cm TL; n = 64) ranged from 2 to 3 years. The fish from Rijpfjorden were smaller at age than those from Kongsfjorden, and their growth rate between years 2 and 3 (no other age classes were available) was approximately 3.3 cm year−1. In both fjords, males and females were of the same size-at-age and the same weight-at-TL. The small sampling area means that the results on growth rate are not representative of the entire fjords. Instead, the results can be discussed as presenting the possible growth rates of some populations. A strong relationship was identified between otolith size (length and weight) and fish size (TL and TW), with no differences between males and females or the fjords. A significant, strong relationship was also noted between fish and otolith growth rates.
3
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The relationship between fish length and otolith size and weight of Acanthopagrus arabicus Iwatsuki, 2013 (Sparidae) collected from the Iraqi marine waters

100%
Jawad L., Qasim A., Al-Zaidy F. M., Waryani B., Rutkayova J.
Acta Scientiarum Polonorum. Zootechnica
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2021
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tom 20
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nr 1
4

Fish in the diet of the Cormorant and the Yellow-legged Gull breeding near fish ponds [upper Vistula river valley, Southern Poland] - preliminary study

100%
Gwiazda R.
Acta Zoologica Cracoviensia
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2004
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tom 47
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nr 1-2
Examination of fish in the diet of Cormorants (pursuit divers) and Yellow-legged gulls (surface plungers) in colonies in an area adjacent to fish-ponds was carried out in 2000-2003. The examined colony of Cormorants consisted of 41-45 nests and that of the Yellow-legged Gulls – 41-90 nests during the study. The diet of Yellow-legged Gulls in freshwater habitats is not well known. The prey of Cormorants consisted of only seven species of fish. Carp was the most numerous prey at 69% of consumed fish. Fourteen species of fish were recorded in the food of the Yellow-legged Gulls with the domination of carp (38%) and roach (34%). Rheophilous fish made up 5-19% of food by number. Both species caught large fish, but generally Cormorants caught on average larger fish. The same pattern was confirmed when carp was compared. The mean prey size of the Cormorants was 20.6 cm in total length (range 7-41 cm) and that of Yellow-legged Gulls 18.5 cm (range 9-47 cm). Fish are the principal food item for both Cormorants and Yellow-legged Gulls in the studied sites in southern Poland.
5

Sex structure, recruitment rate, and size of maturing specimens of European eel (Anguilla anguilla (L.)) in a population from lakes in northeastern Poland

80%
Robak S.
Archives of Polish Fisheries
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2005
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tom 13
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nr 2
Studies of the sex structure and recruitment rates of silver eels from a population occurring in natural conditions in a large lake complex were conducted in the 1985-1990 period based on a sample of 6998 specimens. The fish were caught in 60 connected lakes with a combined surface area of 300 km2 using box traps, cross traps, stownets on stakes and electric fishing. It was determined that the share of males in the eel population occurring in the lakes was barely 1.03%, and in the group of fish with body lengths (Lt) of up to 46.0 cm it was 3.17%. Silver and yellow eels were noted among both males and females. The share of silver eels increased from 0 to 100% in the body length categories from 39.0 to 46.0 cm among males and from 47.5 to 95.0 cm among females. In both instances, the dependence of the share of silver eels on the total length of the body was described with linear regression with a high correlation coefficient and high regression significance (P < 0.05). The studies indicated that in the lakes of northeastern Poland, which are located within a large complex that is permanently connected, the share of males is small and the recruitment of silver eels from this group occurs within a narrower and lower size range than it does in females.
6

The influence of weight and length on the mercury content in the muscle tissue of fish from four lakes in the Olsztyn Lake District (Poland)

80%
Luczynska J.
Archives of Polish Fisheries
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2005
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tom 13
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nr 1
The total mercury content was determined in the muscle of northern pike, perch, and roach caught in four lakes (Łańskie, Pluszne, Dłużek, Maróz) in the Olsztyn Lake District (northeastern Poland) from October 1999 to October 2000. The total mercury was analyzed with flameless cold vapor atomic absorption spectrometry (CV AAS). The total mercury content in the muscle of pike ranged from 0.076 mg kg⁻¹ (Łańskie) to 0.902 mg kg⁻¹ (Pluszne), in perch from 0.104 mg kg⁻¹ (Pluszne) to 1.277 mg kg⁻¹ (Dłużek), and in roach from 0.074 mg kg⁻¹ (Maróz) to 0.278 mg kg⁻¹ (Maróz). In most cases, the strongest positive correlation (p < 0.001) was found between the Hg concentration in the muscle tissue of the fish and total body weight (0.825 < r < 0.967) or total body length (0.781 < r < 0.950). The exception was the roach from Lake Maróz, where the correlation coefficients between mercury content in the muscle of these fish and their body weight and total length were r = 0.794 and r = 0.788, respectively (p < 0.01). Similarly, with pike from Lake Maróz it was found that the correlation coefficient between the mercury concentration in the muscle of these fish and their total length was r = 0.781 (p < 0.01).
7

Morphometric relations for body size and mouth dimensions for four fish species in the Strait of Gibraltar

80%
Czerwinski I. A., Gutierrez-Estrada J. C., Soriguer M. C., Hernando J. A.
Acta Ichthyologica et Piscatoria
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2008
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tom 38
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nr 2
81-90
Background. The deep-water longline fishery of the blackspot seabream, Pagellus bogaraveo, is an economically important fishery in the Strait of Gibraltar, which is a very complex transition ecosystem between the Mediterranean Sea and the Atlantic Ocean with an extreme spatial and temporal variability. This paper presents a series of morphometric relations for the four most important species in this fishery. Some ecological considerations about the results are also discussed. Materials and Methods. The data were collected during a gear selectivity study, using different sizes of hooks baited with sardine. Relations for weight–length, length–length, and mouth dimensions for blackspot seabream, Pagellus bogaraveo (Brünnich, 1768); Atlantic pomfret, Brama brama (Bonnaterre, 1788); blackbelly rosefish, Helicolenus dactylopterus (Delaroche, 1809); and Mediterranean horse mackerel, Trachurus mediterraneus (Steindachner, 1868) were estimated and compared with the ones reported for the same species from other areas. Results. The sample size varied from 89 for T. mediterraneus to 2180 for P. bogaraveo. The fitted L–W relations explained more than 81% of the variance. For P. bogaraveo and T. mediterraneus, the estimated allometric coefficient was higher than those reported for other areas, showing a faster increase in weight, in contrast to H. dactylopterus and B. brama that showed a slower increase in weight. Moreover, linear and highly significant relations between mouth size and fish length were found for P. bogaraveo, H. dactylopterus, and T. mediterraneus. Conclusion. In this study, the first record for total length–standard length relation for H. dactylopterus is reported based on real measurements. There has been no previous studies on the relation between the different mouth size dimensions for the studied species as well as for mouth size and body length relations for P. bogaraveo and H. dactylopterus. The difference between estimated and reported coefficients might be attributed to different environmental adaptations and to the size ranges used due to the gear-size selectivity.
8

The effect of fish size on the content of zinc, iron, copper, and manganese in the muscles of perch [Perca fluviatilis L.] and pike [Esox lucius L.]

80%
Luczynska J., Tonska E.
Archives of Polish Fisheries
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2006
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tom 14
|
nr 1
The correlation coefficients between fish size (body weight and total length) and the content of zinc, iron, copper, and manganese in muscles of perch, Perea fluviatilis L., and pike, Esox lucius L., were determined. The fish were caught in four lakes (Łańskie, Pluszne, Dłużek, Maróz) located in the Olsztyn Lake District (northeastern Poland) during 1999 - 2000. With the exception of copper in the perch from Lake Pluszne, in all cases the concentrations of zinc, copper, and manganese in muscle tissue decreased with perch body weight and total length. The content of iron in the muscles of perch from Lake Łańskie was correlated negatively with the size of these fish, but in other cases the levels of iron increased or remained constant. The zinc concentration in muscles of pike was correlated positively with the body weight and total length of these fish. A negative correlation between fish size and iron and manganese content was noted at all sites, except with regard to iron in pike from Lake Pluszne. There was a positive correlation between weight or length and copper concentration in pike from lakes Łańskie and Maróz. However, there was a negative correlation between size and copper content in the muscles of pike from lakes Pluszne and Dłużek. The relationship between the contents of selected metals was calculated.
9

Fish digeneans from the Seven Islands Ornithological Reserve at Oswin Lake. Part II. The eyeflukes - Diplostomum spp. and Tylodelphys clavata [Von Nordmann, 1832]

80%
Mierzejewska K., Wlasow T.
Acta Ichthyologica et Piscatoria
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2005
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tom 35
|
nr 1
Background. Aparasitological survey was carried out in a shallow, eutrophic Oświn Lake (north-eastern Poland), within the Seven Islands ornithological reserve. We intended to compare the occurrence of eyeflukes in fish from two, distinctly demarcated pools of the lake, differing in environmental conditions. The effect of fish size and sampling season on the infection parameters was analysed and the present state of the parasite faunas was compared to the literature data. Materials and Methods. Within 1998 and 1999, a total of 1091 fishes representing 8 dominant species was examined. Samples were collected four times a year (in May, July, August, and October) simultaneously from the eastern- and western parts of the lake. Results. Diplostomum spp. occurred in all the fish examined, numerously in roach, rudd, white bream, and carp bream. The parasite was less abundant in northern pike, crucian carp, and European perch. Tylodelphys clavata was found in roach and it sporadically occurred in northern pike, rudd, white bream, carp bream, and European perch. The infection rates of rudd and white bream in the eastern part of the lake were significantly higher than the respective values from the western part. The infection with both eyeflukes did not correlate with the fish length. The infection of roach, rudd, white bream, and carp bream with Diplostomum spp. and roach with T. clavata varied significantly in different experimental periods. Conclusion. The eyeflukes as well as P. cuticola were sensitive indicators, reflecting the environmental pressure-both, spatial differences in ecological conditions within the same water body and long-term alterations. Diplostomum spp. did not accumulate with the age of fish. No seasonality was found for Diplostomum spp. or Tylodelphys clavata. Locationdependent occurrence of Diplostomum spp. in rudd and white bream indicated a limited fish interchange between the two pools of the lake.
10

The relationship between the content of lead and cadmium in muscle tissue and the size of fish from lakes in the Olsztyn Lake District of northeast Poland

71%
Luczynska J., Brucka-Jastrzebska E.
Archives of Polish Fisheries
|
2005
|
tom 13
|
nr 2
Concentrations of lead and cadmium were measured in the muscle of four fish species: pike, Esox lucius L., Eurasian perch, Perca fluviatilis L., roach, Rutilus rutilus (L.), and bream, Abramis brama (L.) collected from four lakes in the Olsztyn Lake District of northeast Poland. The fish were caught in the 1999-2000 period. Heavy metals contents were determined using the flameless atomic absorption spectrophotometry method (GF AAS). The mean lead content in the muscle of pike, perch, roach, and bream was 0.084, 0.098, 0.094, and 0.083 mg kg-1, respectively. Positive correlation coefficients (P< 0.001) were noted between Pb concentration and the body weight and total length of roach and perch (0.481 < r < 0.676, respectively). Negative correlation factors between Pb content and the body weight and length of pike (r = - 0.378, P < 0.01 and r = - 0.549, P < 0.001) and bream (r = - 0.557 and r = - 0.519, P < 0.001, respectively) were noted. The mean content of cadmium in the muscle of pike, perch, roach, and bream ranged from 0.0023 to 0.0025 mg kg-1. There were positive correlations between the levels of Cd in the muscle of roach and perch and body weight (r = 0.401, P < 0.01 and r = 0.323, P < 0.05, respectively) and total length (r = 0.436, P < 0.01 and r = 0.354, P < 0.05, respectively). The correlation coefficients between body weight and total length and the content of cadmium in pike and bream were – 0.228< r < 0.075.
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