Miroslaw Luczynski

Effect of temperature on embryonic and larval development of bream (Abramis brama L.)

Influence of water temperature on embryonic and larval development of bream (Abramis brama L.) was stdied. Eggs of bream were incubated at eight constant water temperatures between 13.2 and 26.8°C. The temperature of 21.1°C gave highest hatching success, with no abnormalities in the eleutheroembryos and lowest mortality observed between eyed egg stage and the time of hatching. Developmental rate increased with increasing temperature. Duration of embryonic development (y; hours) decreased with increasing incubation temperature (x; °C) according to the formula: y=910.1−65.88 x+1.318 x2. Larvae were reared at eight constant temperatures ranging from 13.5 to 34.0°C. The instantaneous growth rate in wet weight increased with increasing test temperature from 13.5 to 29.9°C, and then decreased at higher temperatures. Individual growth of fish and biomass production rate were highest at 27.9°C. This temperature is considered optimal when food availability and photoperiod are no limiting factors.

Critical partial pressures of oxygen causing precocious hatching in Coregonus lavaretus and C. albula embryos

Abstract Embryos of whitefish ( Coregonus lavaretus ) and vendace ( C. albula ) were exposed to various hypoxic conditions at constant temperatures of 8°C and 11°C at the developmental stages of “eye movement visible” and “first embryos hatched”. Eggs exposed to hypoxia responded with precocious hatching and the response depended on the degree of hypoxia, test temperature, and developmental phase. The calculated critical partial pressures of oxygen ( p O 2 ) causing precocious hatching at 8°C were 40 mm Hg (3.0 ppm dissolved oxygen concentration—DO) for whitefish and 28 mm Hg (2.1 ppm DO) for vendace embryos. The sensitivity of embryos to hypoxic stress increased rapidly as development progressed. Eventually, the critical p O 2 for vendace eggs increased to 81 mm Hg (6.0 ppm DO) at the stage of “first embryos hatched”. Higher temperatures caused stronger response of embryos to hypoxia: exposure of whitefish embryos for 60 min to p O 2 of 3 mm Hg (0.2 ppm DO) at 8°C resulted in hatching of 43% of eggs, whereas at 11°C, hatching increased to 95% (at the same oxygen concentration). Adequate DO concentrations must be provided in incubation to prevent early hatching and increased mortality.

The effect of egg yolk, low density lipoproteins, methylxanthines and fertilization diluent on cryopreservation efficiency of northern pike (Esox lucius) spermatozoa.

The effect of egg yolk, low density lipoproteins (LDL) as well as methylxanthines (caffeine and theophylline) and fertilization diluent on cryopreservation efficiency of northern pike, Esox lucius, spermatozoa was tested. Milt was cryopreserved in pellets on dry ice then stored in liquid nitrogen. The extender consisted of 0.6 M sucrose + 15% DMSO supplemented with egg yolk or LDL fractions. The most effective results (77.3% hatched larvae vs 74.1% in the control group) were obtained from extender that contained only 0.6 M sucrose + 15% DMSO and was used for freezing, while the fertilization diluent was used for thawing. Addition of egg yolk or LDL to the extender did not improve the results. The presence of caffeine in the thawing solution significantly lowered fertilization rate of cryopreserved spermatozoa, whereas theophylline did not significantly affect the results. The addition of fertilization diluent to the eggs prior to insemination was superior to the other treatments. The proposed procedure constitutes a complete method for the efficient cryopreservation of northern pike semen.

Rearing of larvae of four coregonid species using dry and live food

Abstract After hatching, the larvae of vendace ( Coregonus albula ), whitefish ( C. lavaretus ), muksun ( C. muksun ) and peled ( C. peled ) were fed solely on a dry diet and compared with those fed zooplankton. The survival rates of the fish groups fed zooplankton were similar (vendace and muksun) or lower (whitefish and peled) than those of the groups fed on the dry diet, whereas the growth rate of the fish fed the live prey was better than that of those fed the pelleted food. It is concluded that the larvae of the examined Coregoninae species can be fed solely on a dry food after hatching with satisfactory growth and survival.

Chromosome polymorphism in Salmo trutta morpha lacustris from Poland, Wdzydze Lake population: Variation in the short arm length of chromosome eleven

Abstract: A population of Salmo trutta m. lacustris from Lake Wdzydze was karyotyped using C-banding and fluorochrome staining techniques. The chromosome number was 2n = 80, and the chromosome arm number (NF) was 100-102. Variation in the size of the short arm of chromosome pair eleven was observed: the presence of heterochromatin on this arm was confirmed by C-banding and DAPI staining. Chromomycin A3 and silver stainings revealed the presence of nucleolar organizer region (NOR) on this arm. Additional CMA3-positive regions were observed on two acrocentric chromosomes. The polymorphism of chromosome pair eleven observed in Salmo trutta m. lacustris probably resulted from deletions or multiplications of heterochromatin connected to NOR. The karyotype and observed polymorphism of the NOR-bearing chromosome pair was the same as observed in other ecological forms of Salmo trutta.

Ploidy Level Determination in Genetically Manipulated Northern Pike Based on the Number of Active Nucleoli per Cell

Abstract Silver-staining of cell preparations followed by counting of the mean number of active nucleoli per cell enabled determination of the ploidy level in genetically manipulated northern pike Esox lucius. Haploid pike resulted from activation of eggs with sperm irradiated with ultraviolet light, and triploid specimens were obtained by applying high-temperature shock. Cells of haploid individuals had one (almost 100% of cells examined) or, sporadically, two nucleoli. Depending on the specimen, mean number of nucleoli per nucleus ranged from 1.0 to 1.06. In diploid fish, the mean number of active nucleoli per cell ranged from 1.58 to 1.81. In triploids, the mean ranged from 2.08 to 2.46. Positive identification of ploidy level in northern pike required examination of up to 40 cells per individual, as determined by the regression analysis. The method required a very small amount of any kind of tissue, enabling determination of ploidy level in juvenile fish without sacrificing them.

Cytogenetic Characterization of Sea Trout (Salmo trutta) from Poland

Cytogenetic analysis of two local populations of sea trout (Salmo trutta) revealed a diploid chromosome number (2n) of 80 and a diploid chromosome arm number (NF) of 102. Two heteromorphic chromosome pairs were identified, based on Cbanding and DAPIand CMA3-staining: NOR-bearing pair 11 and metacentric pair 6. The study was designed to search for chromosome markers enabling separation of fish from one of the Pomeranian rivers (Slupia River) compared to those from the Vistula River. Frequencies of the heteromorphic chromosome pairs identified genetic differences between the two groups.

Heterochromatin and NOR location in northern pike (Esox lucius)

Abstact: Heterochromatin and the location of nucleolar organizer regions (NOR) were analyzed in northern pike (Esox lucius). The degree to which heterochromatin is present and its location are indicators of reorganization in karyotypes. Karyotypic analysis along with the use of conventional banding techniques and fluorochromes showed that the standard karyotypes was 2n = 50 chromosomes, with 50 chromosome arms (NF). NOR showed C- and CMA3-positive staining and were localized near the centromere of chromosome pair No. 11. Sequential staining using C-banding and DAPI techniques showed bright dots in the same region where NOR were localized.¶No sex heterochromosomes were recognizable on the basis of the staining techniques applied.

Recovery and Analysis of Mitochondrial DNA from Ancient Bones of Common Bream, Abramis brama L.

Cyprinid remains were collected from an archaeological site at Wolin, Poland. DNA has been extracted from a 1000 years old bone of common bream, and a 172 bp fragment of the cytochrome b gene of the mitochondrial DNA (mtDNA) successfully amplified by the polymerase chain reaction. The obtained fragment has been sequenced, and showed one point mutation (G ! A) at the position 123 of the gene.

Masculinization of Northern Pike Fry Using the Steroid 11 β-Hydroxyandrostenedione

Abstract Morphological and histological studies of gonads demonstrated that 11 β-hydroxyandrostenedione (11 β-HA) can be used to control the phenotypic sex in northern pike Esox lucius. Oral administration of 11 β-HA (30 mg/kg pelleted food) to northern pike juveniles (average total length ± SD = 2.80 ± 0.18 cm) for 2 weeks resulted in sex reversal of most of the females and produced a stock that consisted of 87% males and 13% bisexual animals. Testes of hormone-treated fish possessed seminal ducts and were characterized by a regular morphology, but histological observations showed that germ cells differentiated earlier in ontogeny than we observed in the gonads of untreated fish. Gonads of bisexual fish were morphologically ovaries or testes but in either case contained both female and male germ cells, although in some individuals atrophy of individual oocytes was observed. We obtained practical information on effectiveness of the androgen application (timing, duration, and dose) to northern pike juveniles.