Triploid Fish Research Articles

Microhabitat use and seasonal movements of hatchery-reared and wild shortnose sturgeon in the Savannah River, South Carolina - Georgia

Summary Radio and acoustic telemetry were used to monitor the seasonal movement of hatchery-reared and wild shortnose sturgeon (622–927 mm total length) in the Savannah River. Diploid, and sterile hatchery-reared shortnose sturgeon, and wild shortnose sturgeon showed apparent similar seasonal patterns of movement within the river. We were unable to detect any significant differences in the seasonal mean river location, minimum daily distance moved, absolute distance moved, displacement or mean territory size among treatments. Fish moved throughout the brackish and freshwater interface area of the Savannah River during the summer months. Coinciding with decreasing fall temperatures, fish of all treatment groups moved downriver into brackish areas of the upper estuary, residing in the Front, Middle, and Back Rivers, where they remained through winter. Upriver movements of some hatchery-reared and wild groups began in early February as river temperatures began to increase. Shortnose sturgeon from each group selected apparent similar thermal, salinity and water depth conditions throughout the year. Hatchery-reared fish may be useful as surrogates for wild fish in behavioural studies. Triploid or surgically-sterilized fish may be used in situ behavioural studies where genetic contamination is a concern. It may be possible to monitor habitats used by released hatchery-reared fish to locate or verify remnant populations of rare or endangered species in systems where they are thought to be extirpated.

Ovaprim treatment promotes oocyte development and milt fertilization rate in diploid and triploid African catfish (Clarias gariepinus)

Triploid fish are increasingly used in aquaculture because they are generally unable to reproduce successfully. Energy is channeled into somatic growth rather than gonadal development, and in the event of escape, the animals are unlikely to breed successfully among themselves or with wild conspecifics. This study tested the ability of recently matured triploid African catfish (Clarias gariepinus) to produce and fertilize eggs with and without ovaprim treatment. Triploid females did not show the increase in ovary size observed in diploid members of the same cohort between 8 and 9 months of age, or the coincident decrease in visceral fat deposits, and this was unaffected by up to 5 weekly i.m. injections of 0.5 ml kg−1 Ovaprim. However, we observed advanced vitellogenin (Vtg) sequestration in oocytes of triploid females, albeit to a lesser degree and with lesser cortical alveoli, compared to oocytes from diploid cohort members. Histological sections revealed a positive trend of oocyte development up to the third weekly ovaprim injection followed by a negative gonadal development in weeks four and five. Milt from triploid males injected 9–12 h earlier with 0.25 ml kg−1 ovaprim i.m. fertilized more diploid eggs than milt from untreated triploid males (30 vs. 20%), but none of the developing embryos of triploid paternity survived to hatch. In contrast, milt of diploid males fertilized 49% of eggs, and 20% of the developing embryos hatched successfully. These rates were improved in ovaprim-injected diploid males to 70% fertilization and 33% hatch. This study demonstrates potential of overcoming non-viability of eggs from triploid female African catfish, and enhancing the ability of triploid milt to fertilize eggs.

Parr–smolt transformation in out-of-season triploid Atlantic salmon (Salmo salar L.)

Production of sterile triploid Atlantic salmon (Salmo salar) would appear to be the best strategy to address the growing concerns on environmental impacts of escapees. However, the industry relies on a year round supply of smolts to ensure continual production and to date the production of out-of-season (S0+) triploid smolts has not been reported. The present study demonstrates that S0+ triploid smolts can be produced using an accelerated “square-wave” photoperiod (LL–LD 9.5:14.5–LL) under ambient water temperature. Such a regime advanced the timing of smoltification by 3months (S0+) relative to their siblings under an ambient photoperiod (S1+) as observed through body silvering, fin darkening, decrease in condition and significantly increased gill Na+, K+-ATPase activity. Importantly, triploid S0+ fish smolted 4weeks earlier than their diploid siblings. In S1+ populations, no difference in smolt time was observed although triploid fish also achieved a higher weight. Furthermore, deformity prevalence was very low during the fresh (≤5%) and seawater (≤2.5%) stages within both ploidies mainly represented by spinal deformity and operculum shortening. Family effects for growth and condition were clear, however, no significant family/ploidy interactions were observed although this was based on only two full-sib crosses. These results are promising but there is still a long way to go before triploid can become a commercial reality. Further studies are required to optimize and refine husbandry protocols, define breeding strategies especially regarding family selection and overall better understand triploid salmon physiology.

The culturable intestinal microbiota of triploid and diploid juvenile Atlantic salmon (Salmo salar) - a comparison of composition and drug resistance

BackgroundWith the increased use of ploidy manipulation in aquaculture and fisheries management this investigation aimed to determine whether triploidy influences culturable intestinal microbiota composition and bacterial drug resistance in Atlantic salmon (Salmo salar). The results could provide answers to some of the physiological differences observed between triploid and diploid fish, especially in terms of fish health.ResultsNo ploidy effect was observed in the bacterial species isolated, however, triploids were found to contain a significant increase in total gut microbiota levels, with increases in Pseudomonas spp., Pectobacterium carotovorum, Psychrobacter spp., Bacillus spp., and Vibrio spp., (12, 42, 9, 10, and 11% more bacteria in triploids than diploids, respectively), whereas a decrease in Carnobacterium spp., within triploids compared to diploids was close to significant (8% more bacteria in diploids). With the exception of gentamicin, where no bacterial resistance was observed, bacterial isolates originating from triploid hosts displayed increased resistance to antibacterials, three of which were significant (tetracycline, trimethoprim, and sulphonamide).ConclusionResults indicate that triploidy influences both the community and drug resistance of culturable intestinal microbiota in juvenile salmon. These results demonstrate differences that are likely to contribute to the health of triploid fish and have important ramifications on the use of antibacterial drugs within aquaculture.

Image cytometric measurements of diploid, triploid and tetraploid fish erythrocytes in blood smears reflect the true dimensions of live cells

Comparative image cytometry of erythrocytes of diploid and triploid tench Tinca tinca L. and evolutionary tetraploid sterlet Acipenser ruthenus L. was performed on whole live unstained cells, live cells with stained nuclei and on stained fixed whole cells and their nuclei to test if erythrocyte measurements made from blood smears reflect the true dimensions of live cells. Nuclear area and perimeter were the best ploidy level predictors distinguishing accurately among live and fixed diploid, triploid and tetraploid cells, without significant differences between live and fixed cells within a ploidy level. Redundancy analysis revealed insignificant marginal effect of fixation (explained 2.3% of variation, F = 0.804), whereas the effect of ploidy level was highly significant (explained 50.6% of variation, F = 34.874). The erythrocyte measurements of diploid, triploid and tetraploid fish erythrocytes and their nuclei made from blood smears reflect the true dimensions of live cells, and the fixation procedure did not substantially affect their predictive value for ploidy level determination.

High Gyrodactylus salaris infection rate in triploid Atlantic salmon Salmo salar

We describe an unusually high infection rate of Gyrodactylus salaris Malmberg in juvenile Atlantic salmon Salmo salar L. of Baltic Sea origin, which are generally believed to be more resistant to G. salaris than East Atlantic salmon populations. Based on analyses of mitochondrial (complete cytochrome oxidase 1 [CO1] gene, 1548 bp) and nuclear (ADNAM1, 435 bp; internal transcribed spacer [ITS] rDNA region, 1232 bp) DNA fragments, the closest relatives of the characterized Estonian G. salaris strain were parasites found off the Swedish west coast and in Raasakka hatchery, Iijoki (Baltic Sea, Finland). Analyses of 14 microsatellite loci of the host S. salarrevealed that approximately 40% of studied fish were triploids. We subsequently identified triploid Atlantic salmon of Baltic origin as more susceptible to G. salaris infection than their diploid counterparts, possibly due to compromised complement-dependent immune pathways in triploid salmon. This is in accordance with earlier studies that have shown elevated susceptibility of triploids to various viral or bacterial pathogens, and represents one of the first reports of increased susceptibility of triploid salmonid fish to an ectoparasite. However, further experimental work is needed to determine whether triploid Atlantic salmon is generally more susceptible to G. salaris compared to their diploid counterparts, irrespective of the particular triploidization method and population of origin.

Differential incidence of gonadal apoptosis in triploid-induced male and female turbot ( Scophthalmus maximus)

In order to further investigate the reproductive physiology of triploid turbot, Scophthalmus maximus, the gonadal development and the incidence of apoptosis were studied in diploid and triploid fish at up to 28 months of age. Within the period studied, diploid males completed the reproductive cycle and produced spermatozoa, while the most advanced cell type observed in triploid males was spermatids. In diploid females, preovulatory oocytes were observed, whereas in triploid females a nearly total meiosis blockade was evident with only a small number of oogonia achieving the perinucleolar oocyte stage. Testosterone levels in males were similar regardless of ploidy level with peaks observed immediately before the completion of spermatogenesis; however, peaks were advanced in triploids. Estradiol levels remained very low in triploid females. In diploid males, apoptosis was observed only at the start of spermatogenesis and during testicular regression. In contrast, triploid males had an overall higher rate of apoptotic cells which was constant throughout the reproductive cycle. In diploid females, few or no apoptotic cells were observed in contrast to triploid females where these numbers were markedly increased followed by an overall downward trend as oogenesis progressed. These data suggest that apoptosis plays a role in the control of germ cell number and fate and this regulatory mechanism is magnified in females bearing three sets of chromosome. Thus, the sex-related effects of triploidy on gonadal development in turbot, and likely in fish, include an increase in apoptosis, particularly in females.

The fast growth and sterility of the growth hormone gene transgenic triploid carps

Triploid carps (100%) with 150 (3n=150) chromosomes were obtained by crossing improved tetraploid hybrids ( ♀ , 4n=200) of red crucian carp common carp with diploid yellow river carp (♂, 2n=100). Using PCR detection with specific primers, the transgenic triploid carps (positive triploid fish) which accounted for 44.2% and the non-transgenic triploid carps (negative trip-loid fish) were identified from the triploid carps. On tissue sections, the gonads of 24-month-old positive triploid fish were found to be sterile, and were not able to produce mature gametes during the breeding season. Morphologically, both the positive and negative triploid fish were similar. They had a spindle-shaped, laterally compressed, steel grey body with two pairs of bar-bels. Most of the countable and measurable traits of the triploid carps were intermediate between those of the two parents. Over the last 2 years, the positive and negative triploid fish have been raised in the same ponds. The mean body weight of the positive triploid fish was 2.3 times higher than that of the negative triploid fish. The highest body weight of the positive triploid fish was 2.91 times higher than that of the negative triploid fish. Thus, this study produced fast-growing transgenic triploid carps with reduced ecological risk because of their inability to mate and produce progeny.

Body shape variation in meiotic gynogenetic and triploid sea bass,Dicentrarchus labrax

A method of geometric morphometrics was used to characterize body shape variation in meiotic gyno- genetic and triploid sea bass in comparison with diploid controls. A total of 13 coordinate landmark data were recorded on the profile of 34-month-old control (n = 81), gynogenetic (n = 117) and triploid (n = 131) siblings generated from two females (A and B). Three main axes of morphometric variation were consistent, and these accounted for 60.8 and 57.6% of the total variability in females A and B, respectively. There were significant shape deviations of triploid and gynogenetic fish relative to the controls, and differences were particularly evident in the progeny of one female. Overall, triploids displayed a more slender shape than diploids, whereas gynogenetic fish were deeper bodied and had flexed caudal peduncles and cranial features. The results are discussed especially in relation to the characterization of triploid fish for commercial purposes.

Survival of Diploid and Triploid Rhamdia quelen Juveniles Under Different Oxygen Concentrations

The objective of this study was to determinate the lethal concentration of dissolved oxygen (DO) over 96 hours of exposure (LC50–96h) for diploid and triploid jundia Rhamdia quelen juveniles. Diploid and triploid fish weighing approximately 4 g were subjected to DO concentrations varying between 0.4 and 1.3 mg O2 L−1; water temperature was maintained at 27 °C and pH at 6.3. The LC50–96h for diploids of Rhamdia quelen was 0.535 mg O2 L−1, while the value obtained for triploids was 6% greater. These results demonstrated that triploids of Rhamdia quelen juveniles have greater sensitivity to hypoxia compared to diploids.

Genetic constitution and phylogenetic relationships of Japanese crucian carps (Carassius)

The genetic constitution and phylogenetic relationships among the proposed species and subspecies of the crucian carp complex in Japan (Carassius cuvieri, C. auratus subspp. 1 and 2, C. a. grandoculis, C. a. buergeri, and C. a. langsdorfii) were investigated based on analyses of the partial nucleotide sequences of the mitochondrial DNA control region and amplified fragment length polymorphisms of nuclear DNA. Our results demonstrate that C. cuvieri and C. auratus are different entities. However, although several distinct lineages were observed for C. auratus, none corresponded to the proposed subspecies. Moreover, the five subspecies of C. auratus were not necessarily separated genetically from each other. Triploid fish, which are currently classified as a single subspecies (C. a. langsdorfii) but are sometimes treated as an independent species, fell into various clades along with diploid individuals of other subspecies that have the same or similar mitochondrial haplotypes. This suggests that gynogenetic triploid crucian carps distributed throughout the Japanese Archipelago have polyphyletic maternal origins. Our results indicate that Japanese crucian carps are a much more complex assemblage than previously believed.

Effect of triploidization on juvenile African catfish (Clarias gariepinus)

Triploid African catfish (Clarias gariepinus) produced through cold shock 3 min post fertilization were compared to diploid offspring of the same parentage at 66 days of age. Triploid fish were significantly shorter (11%) and weighed less (18%) than diploids but showed no significant difference in mortality or cannibalism, which can be an important source of losses under aquaculture conditions. Erythrocytes of triploid fish were more oval shaped than the normal spherical shape of diploid erythrocytes, were significantly larger (38%) and had nuclei that were significantly larger (25%) than observed in diploid fish. Erythrocyte morphological characteristics show potential as an indicator for the detection of triploidy in African catfish.

Does triploidization produce functional sterility of triploid males of tench Tinca tinca (L.)?

Triploidy interferes with gametogenesis in all fish species tested so far. In fish it results in complete female sterility however, males are still able to develop testis. The reason why sterility levels in triploid fishes differ among species and between sexes is unclear. In the present study the reproductive capacity of triploid males of tench was studied. Flow cytometry revealed sperm cells of triploids to be largely aneuploid with high mosaic DNA, oscillating from haploid DNA to diploid DNA content. Analysis of variance showed an insignificant influence of ploidy level on the percentage of motile spermatozoa, as well as on spermatozoa velocity. Experimental crosses between normal diploid female and triploid males resulted in the appearance of triploid progeny, which exhibited genotypes composed of microsatellite alleles inherited from the founder female and additional allele derived from the donor male. We can conclude that the triploid males analysed in the present study were capable to fertilize eggs derived from diploid females.

Coronary vascular volume remodelling in rainbow troutOncorhynchus mykiss

The 34% increase in relative ventricular mass (Mrv) resulting from chronic anaemia (induced by an intraperitoneal injection of phenylhydrazine hydrochloride) was accompanied by a 117% increase in coronary vascular volume of diploid rainbow trout Oncorhynchus mykiss. Coronary vascular volume of normocythemic triploid fish was similar to that of normocythemic diploid fish despite a larger Mrv. These observations, in combination with previous studies, suggest that the vascularity of compact myocardium in O. mykiss can vary independently of Mrv.

Survival of diploid and triploid Rhamdia quelen juveniles in different ammonia concentrations

Triploidy is a common chromosomic manipulation technique used in fish culture to eliminate gonadal maturation and also to obtain other advantages. However, studies demonstrate that triploid fish exhibit some structural differences in the central nervous system and sensory organs, suggesting distinct behavioral or physiological responses to the environment when compared to diploid fish. The objective of this study was to determine the lethal concentration of ammonia nitrogen (NH 3–N) over 96 h of exposure (LC50-96h) for diploid and triploid jundiá Rhamdia quelen juveniles. Diploid and triploid fish weighing approximately 10 g were subjected to NH 3–N concentrations varying between 0.8 and 3.4 mg L − 1 NH 3–N; the dissolved oxygen concentration remained saturated, with a pH of 8 and a water temperature of 25 °C. The LC50 for the diploid fish was 2.99; 2.26; 2.00 and 1.91 mg L − 1 NH 3–N and for triploid 2.39; 2.03; 1.96 and 1.91 mg L − 1 NH 3–N, in 24, 48, 72 and 96 h, respectively. The results indicate a greater sensitivity of triploid fish in the first 48 h of exposure to ammonia than of diploid ones; however, the tolerance of the ammonia for triploid fish increased with exposure time, and the accumulated mortality value became similar between both ploidies after 96 h of exposure.

Transcriptional differences between triploid and diploid Chinook salmon (Oncorhynchus tshawytscha) during live Vibrio anguillarum challenge

Understanding how organisms function at the level of gene expression is becoming increasingly important for both ecological and evolutionary studies. It is evident that the diversity and complexity of organisms are not dependent solely on their number of genes, but also the variability in gene expression and gene interactions. Furthermore, slight differences in transcription control can fundamentally affect the fitness of the organism in a variable environment or during development. In this study, triploid and diploid Chinook salmon (Oncorhynchus tshawytscha) were used to examine the effects of polyploidy on specific and genome-wide gene expression response using quantitative real-time PCR (qRT-PCR) and microarray technology after an immune challenge with the pathogen Vibrio anguillarum. Although triploid and diploid fish had significant differences in mortality, qRT-PCR revealed no differences in cytokine gene expression response (interleukin-8, interleukin-1, interleukin-8 receptor and tumor necrosis factor), whereas differences were observed in constitutively expressed genes, (immunoglobulin (Ig) M, major histocompatibility complex (MHC) -II and beta-actin) upon live Vibrio anguillarum exposure. Genome-wide microarray analysis revealed that, overall, triploid gene expression is similar to diploids, consistent with their similar phenotypes. This pattern, however, can subtly be altered under stress (for example, handling, V. anguillarum challenge) as we have observed at some housekeeping genes. Our results are the first report of dosage effect on gene transcription in a vertebrate, and they support the observation that diploid and triploid salmon are generally phenotypically indistinguishable, except under stress, when triploids show reduced performance.

INDUCTION OF GYNOGENESIS IN GOLDFISH USING SPERMATOZOA OF BLUNT SNOUT BREAM

Our previous studies reported that a new triploid fish was produced by crossing the females of goldfish(Carassius auratus Goldfish) with the males of allotetraploid hybrids of red crucian carp(♀) × common carp(♂).Compared this new triploid fish with Xiangyun crucian carp(Japanese crucian carp(♀) × allotetraploid hybrids(♂)),the new type of triploid crucian carp not only presented some advantages which the Xiangyun crucian carp had,such as faster growth rate,wider adaptability,sterility and stronger anti-disease ability,but also got some new good performances like the high ratio of the width to the length of the body and sweet flesh.Goldfish is a kind of the most important species of ornamental fish in China that has centuries-old feeding history,but it has poor capacity of disease resistance and adaptability and so on.As the female parent of the new type triploid hybrids,goldfish was highly expected to be genetically improved.In order to reach the aims,we used sperm from blunt snout bream(Megalobrama amblycephala) which were genetically inactivated by an appropriate UV dosage to activate the development of the egg of goldfish to artificial gynogenesis.In this paper,gynogenetic diploid was induced in goldfish eggs to gynogenesis using UV-irradiated spermatozoa from blunt snout bream,then the maternal DNA was duplicated with cold shock in the 0—4℃ cold water for 51—58 min to retain the second polar body.The experiment could obtain survivable individuals,and the fertilization rate,hatching rate and survival at the first feeding were(62.7±2.7)%,(30.1±4.3)% and(6.2±1.1)%,respectively.In this paper,we checked the individuals by morphological characteristics,chromosome number and the degree of gonadal development.Because blunt snout bream and goldfish belong to different subfamilies in zootaxy,using UV-irradiated spermatozoa of blunt snout bream not only can make the evaluation of gynogenetic status more easily,but also more easily to distinguish gynogenetic goldfish from the control hybrids just according to the chromosome number,the morphological characteristics and the degree of gonadal development.The successful gynogenetic goldfish generated offspring with 100 chromosomes,all of which were female that had double tails,looked like the goldfish and had normal gonadal.However,the individuals with 124 chromosomes were generated by hybrids of goldfish × blunt snout bream.They had single tail looked like the crucian,and the gonadal development was delayed.In the present study,it suggested that the spermatozoa of blunt snout bream were an effective activation source for inducing gynogenesis in crucian carp,and we could avoid exploring the genetic markers at the biochemic or molecular levels.This research obtained gynogenetic goldfish that no male was found in all gynogenetic goldfish examined randomly,and the presence of all female gynogenetic diploids matured at one year old provided cell genetics evidence to the goldfish's sex determination mode-XX/XY.Furthermore,the gynogenetic individuals had two types of offspring which had two kinds of color that were different from their female parent,and it might be conduced by allele homologizing or by allogynogenesis.

STUDIES ON CLONAL DIVERSITY OF GIBEL CARP, <I>CARASSIUS AURATUS GIBELIO</I>, FROM THE IRTYSH RIVER WATER SYSTEM IN XINJIANG PROVINCE

Gibel carp, Carassius auratus gibelio Bloch, as a subspecies of Carassius auratus, has a wide geographic distribution from northern Europe to Asia. As a new culture target, it has been used widely for aquaculture practice in recent 30 years in China, and its production capacity has increased up to 2 billion kilograms annually. Gibel carp possess several interesting characteristics: 1) It is a triploid fish with more than 150 chromosomes, 2) It exists as a bisexual population with predominantly more females (an 80 : 20 female: male ratio) in natural habitats, 3) It has dual reproductive modes of gynogenesis and bisexual reproduction, 4) Various gynogenetic clones have been identified. These features make gibel carp a promising study model for evolutionary genetics, developmental biology and selective breeding. Recently, we have detected clonal diversity of gibel carp in Fangzheng stock hatchery of Heilongjiang Province and Qihe stock hatchery of Henan Province. Up to now, however, little information had been known about the status of gibel carp populations from the Irtysh River water system in Xinjiang Province. In order to obtain a better understanding of the status of clonal diversity of the gibel carp populations, four populations of Carassius auratus were collected from the Irtysh River water system in this study. Flow cytometry was applied to analyze their blood cells, revealing that all of them were triploid gibel carp. Then, a total of eight different clones were clearly discriminated from these gibel carp populations by analysis of serum transferrin phenotypes. Among them, four clones were identical to those identified previously, whereas, the other four were new. Clones A and M were the most wide-ranging, occurring in all of the four populations. Clone J appeared in two populations. Each of the other five clones was specific to single population. These distribution patterns of different clones within populations might reflect clones being able to migrate and differences in viability of a clone among different water bodies. Among these sampled populations of gibel carp, one had the level of clonal diversity obviously lower than those in the other tree, similar to those in populations reported, probably suggesting negative effects of human activities such as hydraulic engineering construction and overharvesting. The clonal diversity revealed in this study will likely benefit evolutionary genetics and selective breeding studies. At the same time, this work also highlights the significance of protecting clonal diversity Of gibel carp in the Irtysh River water system.

Milt characteristics of diploid and triploid Atlantic cod (Gadus morhuaL.)

The work compares the characteristics of milt produced by diploid and triploid Atlantic cod in terms of sperm motility, density, DNA content, seminal-fluid composition and the ability of sperm to fertilize the eggs. The mean track velocity (VCL) was higher in the sperm of diploid than in the triploid males at 20 s post-activation (p.a.; 124.04 ± 6.91 vs. 113.32 ± 6.32 μm s−1), but not at 40 s p.a. No differences between ploidies were observed for the remaining sperm-motility descriptors as for spermatozoa density, spermatocrit or seminal fluid's variables like pH, osmolarity, Cl−, Na+, Ca2+ and K+ concentration. Triploid males produced aneuploid sperm cells (average 1.46n, range 1.2–1.6n) and the larvae generated from artificial crossings with diploid females showed abnormal morphology and did not survive to exogenous feeding. Plasma concentration of 11-ketotestosterone in sexually mature diploid and triploid males was similar (5.35 ± 1.54 vs. 4.82 ± 1.15 ng mL−1) and no differences were found in the ability of males of both ploidies to induce spawning when held in tanks with diploid females. The paper provides evidence of gametic sterility of triploid males and examines the use of triploid fish as a management option to address the issues of genetic containment of farmed cod alongside measures for securing present fish-farming technologies.

Hematological characteristics and correlations of diploid and triploid Caspian salmon Salmo trutta caspius in juvenile stage

Hematological analysis can provide valuable knowledge for monitoring the health and conditions of both wild and cultured fishes. The objective of this work was to measure and compare of blood parameters and studying their correlations for Caspian salmon Salmo trutta caspius. The values for Hb and HCT were higher for diploid than triploid Caspian salmon (P 0.05) between two ploidies. Lymphocyte individually showed more values for triploid than diploid (P 0.05) in MCV, MCH, and MCHC among diploid and triploid fishes and we found their proportions with greater values for triploid Caspian salmon. The highest and lowest correlation between hematological parameters for diploid Caspian salmon has been found for RBC-MCH (r = -0.81, n = 30, P 0.05), respectively. The greatest and lowest correlation for triploid Caspian salmon were found for MCV-MCH (r = 0.92, n = 30, P 0.05), respectively. Key words: Caspian salmon, Salmo trutta caspius, correlation, diploid, hematological parameters, triploid.