Piotr Hliwa

University of Warmia and Mazury in Olsztyn · Department of Ichthyology and Aquaculture

The aim of this study was to determine the influence of the temperature (range 15 to 25°C), pH (6 to 9) and salinity of water (between 0 to 10‰) on the growth, condition and survival of larvae of the Chinese sleeper. During the 28‐day experimental rearing, the highest average body weight of 81.3 ± 16.3 mg was reached in fish from the group maintain...

Knowledge about paternal-effect-genes (PEGs) (genes whose expression in the progeny is influenced by paternal factors present in the sperm) in fish is very limited. To explore this issue, we used milt cryopreservation as a specific challenge test for sperm cells, thus enabling selection amidst cryo-sensitivity. We created two groups of Eurasian per...

Knowledge about paternal-effect genes (the expression of which in progeny is controlled by the paternal genome) in fish is very limited. To explore this issue, we used semen cryopreservation as a specific challenge test for sperm cells, thus enabling selection amidst cryo-sensitivity. We created two groups of Eurasian perch (Perca fluviatilis) as a...

Globally, fish are frequently introduced beyond their native range. Some, like Ponto-Caspian gobies, are becoming invasive, achieving high colonization rates and constituting frequent prey for native predators. However, little is known about the effectiveness of antipredator behaviors of the invaders, which may shape their role in the invaded commu...

Transcriptomic analysis of freshly hatched fish larvae offers insights into phenotype development, yet it remains uncertain whether it reflects parental influence or predicts individual growth. This research scrutinizes the transcriptome of 16 Eurasian perch (Perca fluviatilis) larval groups alongside pre- and post-hatching traits. Despite consiste...

Did you know we could explore some paternal effect genes using semen cryopreservation as a challenge test? Please take a quick read of how we did that, what results we obtained, and what we have put forward in the form of a poster.

Telomerase activity has been found in the somatic tissues of rainbow trout. The enzyme is essential for maintaining telomere length but also assures homeostasis of the fish organs, playing an important role during tissue regeneration. The unique morphological and physiological characteristics of triploid rainbow trout, when compared to diploid spec...

Mercury belongs among the highly hazardous substances present in the environment and represents a great health risk for many animals including predatory and piscivorous birds. The aim of this study was to assess the total mercury content in the main detoxifying organs (liver and kidney) and in the muscles of adult great cormorants (Phalacrocorax ca...

The molecular identification of Cystidicola farionis (a swim bladder nematode of European smelt from the Vistula Lagoon in Poland) was performed. Their prevalence level was determined, and changes in the trehalose synthesis pathway in larvae and adult nematodes were demonstrated. The trehalose level was almost four times higher in adult nematodes t...

The aim of the study was to examine the daily and seasonal dynamics of changes in fish communities in two environmentally different littoral zones of the Włocławek Reservoir (central Poland), i.e., the floodplain (limnic Dobiegniewo site) and lotic area (Murzynowo site). During seasonal catches using trawl nets, in the daily cycle (at 00.00, 06.00,...

Use of parental individuals from allochthonous lineages to produce stocking specimens resulted in genetic contamination of many local European grayling (Thymallus thymallus) populations. Stocking programs including triploid individuals that are not able to reproduce with stocks located in natural habitats due to being reproductively sterile could c...

This study emphasis improved semen cryopreservation protocol for commercial scale fertilization in European perch. The optimized procedure involves a new extender (GM 25 K) containing 0.30 M glucose, 7.5% methanol and 25 mM KCl at 3.0 × 10⁹/mL spermatozoa. The supplementation of glucose-methanol extender with 25 mM KCl enabled high sperm motility (...

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are of increased concern due to their bioaccumulation in humans and the biota; the health risk they pose to humans and other animals; and their persistency in the environment. In this study, the occurrence of PFAS in selected tissues from pike (Esox lucius L.) and roach (Rutilus L.) collected fro...

The effects of three commercial diets (AF PE and PP) that differed in nutritional value on growth, cannibalism and survival in Eurasian perch post-larvae were performed. Of the feeds used, the PE feed contained a lower level of crude protein and a higher level of crude fat with a higher level of saturated fatty acids (SFA) and a lower level of poly...

Domestication and selective breeding can mitigate current bottlenecks in European perch aquaculture. Monitoring the condition and stress tolerance of European perch stocks from different recirculating aquaculture systems is of general interest to set the baseline values of promising candidates for further breeding processes. We recorded morphometri...

Sex reversal has been used as a breeding strategy by salmonid fish to produce genetically and phenotypically single sex populations. Production of all-female fish has great importance for the creation of monosex female triploids of salmonid fish, which are valued for their sterility, lack of female maturation, and larger commercial size. Among salm...

To assess the effects on rainbow trout reproduction of feed contamination with zearalenone (ZEN) at the current European guidance value (2 mg∙kg⁻¹ feed), we performed a life-cycle feeding trial under aquaculture conditions. The trial began when the fish larvae commenced external feeding and continued for 96 weeks, up to the point when the fish reac...

The effect of size sorting on rearing effectiveness in Eurasian perch post-larvae was evaluated. A 34-day-old perch were reared for 2 weeks in three experimental groups as a small size group (SM, mean weight 0.061 ± 0.011 g), large size group (SL, mean weight 0.148 ± 0.024 g), and unsorted group (US, mean weight 0.105 ± 0.048 g) in recirculating aq...

To investigate the effects of feed contamination with zearalenone (ZEN) at the current European Commission (EC) guidance value (2 mg⋅kg⁻¹ feed) on the growth and health of rainbow trout, we performed a long-term feeding trial under aquaculture conditions. It started with the external feeding of the fish larvae, and continued for 96 weeks, at which...

Yellow semen syndrome (YSS) is the most widely recognized problem among male turkeys. Yellow semen is of low quality and, when used for insemination, results in reduction of fertility and hatchability. Elevated level of serum albumin-like protein accession no. XP_003205725 is a characteristic feature of yellow seminal plasma suggesting albumin role...

Reports published in recent years on the increased risk in the Baltic Sea of fish infection with larvae of nematodes potentially pathogenic to humans have prompted a study of European smelt Osmerus eperlanus with respect to the presence of these parasites in the Vistula Lagoon. Additionally, samples of this fish from Lake Hańcza were comparatively...

Investigation of the heterogametic sex in sterlet Acipenser ruthenus L. was performed using meiotic gynogenesis and gonadal histology. Eggs from the albino females were activated by UV irradiated sperm of wild colored males and exposed to a heat shock. The resultant fish were all albino and exhibited exclusively maternal inheritance of the microsat...

The aim of this study was to investigate the use of Artemia salina nauplii enriched with chosen fluorochromes for mass marking vendace Coregonus albula (L.) larvae. In the experiment, vendace larvae (6 DPH) were fed with live or frozen A. salina nauplii immersed in tetracycline hydrochloride (TC), calcein (Cal) or alizarin red S (ARS) for four subs...

The goal of the present research was to evaluate the efficiency of 11β-hydroxyandrostenedione (OHA) applied in the diet to achieve sex reversal in the European whitefish (Coregonus lavaretus). At 32 day post-hatching, fish were reared in four groups: fish fed with 10 ppm of OHA (10 OHA), fish fed with 20 ppm of OHA (20 OHA), fish fed without OHA (C...

The worldwide spread of bigheaded carp (Hypophthalmichthys spp.) is considered an ecological threat and problem in many countries. The aim of this study was to consider the likelihood of bigheaded carp reproduction in Lake Balaton and its catchment area (Hungary). The within-year trends of gonadosomatic index values show that female bigheaded carp...

In species like rainbow trout (Oncorhynchus mykiss) that show male heterogamety (XY), induced androgenesis results in production of females (XX) and males (YY). Morphological and genetic differences between rainbow trout X and Y chromosomes suggest that androgenetic males (YY) may show lower survival than androgenetic females (XX). To test this hyp...

In this study, gonadogenesis, the effect of temperature (15, 20 and 25 °C) on sex differentiation, and annual changes in the gonads of mature lake minnow Eupallasella percnurus (Pallas, 1814) were determined. The lake minnow was found to be a primary gonochoristic fish species, where gonads are formed directly in the ovaries or testes. The morpholo...

The aim of this study was to investigate the effectiveness of the per os marking method of otoliths in burbot at different early life stages. In experiment E1 burbot larvae 12 (DPH) and in E2 - 22 (DPH) were fed with live artemia salina nauplii immersed in alizarin red S (ARS) and tetracycline hydrochloride (TC), for 1, 3, or 6 subsequent days (in...

The aim of the present study was to verify the feasibility of using live Artemia salina nauplii embedded with fluorochromes for the mass marking of pike Esox lucius (L.) larvae. In the experiment, pike larvae 6 days post hatch were fed ad libitum with nauplii dyed with 600 ppm tetracycline hydrochloride (TC) or 200 ppm alizarin red S (ARS) for 3 or...

The paper presents review of experimental triploidization trials in percid fishes, important for European aquaculture due to improve and diversification of fish production. The triploidization lead to obtain individuals with three sets of homologous chromosomes (3n) theoretically sterile and showing a faster growth rate compare to the normal diploi...

To gain insight into the possible implications for aquaculture of the presence of ZEN in fish feed at the EC guidance level, we determined the effects of over two months of feeding of premarket size rainbow trout (~ 250 g) with ZEN-contaminated feed at a dose of 1.81 mg·kg− 1 feed (90.5% of the current guidance value) under aquaculture conditions....

The effectiveness of restocking is an important element of sustainable fishery. In restocking programmes, where larvae and juveniles are used mass marking is carried out with non-toxic dyes such as fluorochromes transferred into the fish body by immersion or with feed. The experiment was carried out to assess the possibility of using commercial fee...

Monosex stocks of fish become increasingly important in the aquaculture. In fish with male heterogamety, mating females with neo-males i.e. hormonally sex reversed (masculinized) females results in “all-female” stocks. Masculinization is usually performed by administration of androgens such as 11β-hydroksyandrostenedione (OHA) to fish before or dur...

A method for the mass marking of ide Leuciscus idus larvae by feeding them Artemia salina nauplii that were immersed in different solutions of alizarin red S, tetracycline hydrochloride and calcein was tested. The best quality marks were obtained after feeding fish for 4 days with nauplii that had been immersed in 200 mg l(-1) alizarin red S. © 201...

The aim of this study was to develop effective methods for short-term storage and cryopreservation of lake minnow Eupallasella percnurus sperm using extenders. A total number of 50 and 40 individual semen samples were collected in 2010 and 2013 year, respectively. The extenders - VRT (Volckaert's solution), TLP (modified Tyrode's solution) and BWW...

Gametogenesis and the temporal changes occurring in the ovaries and testes throughout the reproductive cycle in the invasive alien bivalve, Chinese pond mussel Sinanodonta woodiana (Lea), from the heated Konin lakes system (central Poland) were studied using histological techniques. S. woodiana was confirmed to be a gonochoristic species with overa...

Parasitological studies were carried out on pulli (n = 20) collected on a breeding colony near the Włocławski Reservoir on the Vistula River (Central Poland). Larvae of the nematode Contracaecum rudolphii (mean intensity of infection 9.3) were detected in the stomachs of all chicks, with adult worms present in two chicks. Larvae of the nematode Por...

Sperm morphology and regulation of sperm motility of lake minnow Eupallasella percnurus, an endangered cyprinid, were investigated. Milt characteristics from two isolated populations of E. percnurus were compared to characterize the interpopulation diversity. Electron microscopic studies revealed that E. percnurus spermatozoa comprise simple, unifl...

The European bitterlings (Rhodeus amarus) from the Eastern locations were cytogenetically examined by conventional and molecular techniques. All analyzed individuals presented invariably the same chromosomal constitution of 2n = 48, with 8 metacentrics + 20 submetacentrics + 20 subtelo-acrocentrics and C-banding positive heterochromatin at the peri...

The effect of supplemented commercial diets with diethylstilbestrol (DES—15, 30 and 60 mg kg−1) and 17 β-estradiol (E2—30 and 60 mg kg−1), two chemicals commonly used in sex reversal procedure in fish, on survival and growth parameters of juvenile European catfish (Silurus glanis) was evaluated. During the two experiments, lasting 28 days each, fis...

Ultrasound approach has been used to assess morphology of the gonadal structure in the sex-reversed rainbow trout females (neomales) provided in the course of 11β-hydroxyandrostenedione treatment applied within gonadal differentiation period. Eighteen matured individuals (in range 38.0–48.6 cm of body length and 802–1644 g of body weight) were scan...

Although brook trout and the Arctic char hybrids are able to reproduce, indi-viduals with decreased fertility or even fish that are unable to produce any gametes have been also described. Abnormal gonadal development and disturbances in the gamete production in the char hybrid offspring may be triggered by the odd chromosome number and disturbances...

and histological studies of the brook trout, Salvelinus fontinalis (Mitchill), and the Arctic char, S. alpinus (L.) hybrids Abstract Although brook trout and the Arctic char hybrids are able to reproduce, indi-viduals with decreased fertility or even fish that are unable to produce any gametes have been also described. Abnormal gonadal development...

During the spawning migrations of whitefi sh (Coregonus lavaretus f. lavaretus L.) to Lake Łebsko in Poland during 2009 and 2010, a total of 276 individuals was caught and analysed to determine the retention time of alizarin red S (ARS) marks in their otoliths following marking in 2004 and 2005. ARS marks were visible in the otoliths of 89 specimen...

The aim of the present study was to analyse the occurrence of macroscopically visible ovary alterations in 2 populations of northern pike Esox lucius L. originating from lakes in the Mazurian Lake District (NE Poland). The alterations were characterised by ovary tissue that was morphologically malformed, in part or in whole, and contained immature...

The effect of Ovaprim (salmon GnRH analogue and a dopamine antagonist) treatment on the quantity and quality of smelt (Osmerus eperlanus L.) sperm was studied in relation to time after hormonal stimulation. Sperm was obtained at 0, 24, 48 and 72 h after treatment (n=13/each time point). Computer Assisted Sperm Analysis (CASA) was used to evaluate s...

The production of all-female populations has important economic benefits in commercial rainbow trout aquaculture. The procedure commonly implemented to produce all-female stocks centers on the sex reversal of rainbow trout females via the administration of androgens in the early developmental stages, followed by the egg fertilization of normal fema...

The aim of this study was to describe possible changes in protease and anti-protease activity in the seminal plasma of European perch (Perca fluviatilis L.) during the spawning time. No significant difference in proteolytic activity was observed between the beginning and the late period of the spawning season in perch. Anti-protease activity signif...

This works studies the biochemical (protein concentration, osmolality, antitrypsin activity, lactate dehydrogenase activity) and physiological characteristics (sperm motility characteristics) of semen of sex-reversed female rainbow trout (n=42) obtained with the application of 11β-hydroksyandrostendione for sex reversal. All data were arbitrarily d...

Active protection measures towards the population of lake minnow, Eupallasella percnurus (Pall.), require comprehensive studies on the reproduction biology of this endangered representative of the native ichthyofauna. One of the key issues is the analysis of the reproduction cycle of sexually mature individuals, which enables the explicit determina...

The objectives of this study were to determine the basic parameters of lake minnow, Eupallasella percnurus (Pall.), semen in terms of sperm concentration, seminal plasma composition, and sperm motility. Although E. percnurus milt characteristics are similar in many respects to those of common carp, Cyprinus carpio L., distinct species-specific diff...

Cadmium is a widespread heavy metal that enters the aquatic environment and affects many processes involved in fish reproduction such as sperm motility. Fish seminal plasma proteins can protect spermatozoa against toxic effects of heavy metals. The objective of this study was to demonstrate the ability of a major carp seminal plasma protein-transfe...

The anatomical structure of gonads in coregonids is characteristic for teleost fishes with follicular, synchronous group tape-like ovaries and acinose type, lobulated testes. In some alpine lakes in Switzerland and in water bodies in northern Poland, certain disorders and changes in the macroscopic structure of whitefish Coregonus sp. gonads have b...

During a parasitological survey of two non-native fish species-racer goby Neogobius gymnotrachelus and monkey goby Neogobius fluviatilis-in the Włocławek Reservoir on the lower Vistula River, the monogenean Gyrodactylus proterorhini was recorded for the first time in Poland, and for the first time, the racer goby was listed as the parasite host. Sp...