Crayfish Pontastacus Leptodactylus Research Articles

Single and combined effects of CuSO4 and polyethylene microplastics on biochemical endpoints and physiological impacts on the narrow-clawed crayfish Pontastacusleptodactylus

This study investigated the toxicity of polyethylene microplastics (MPs; <0.02 mm) and CuSO4, alone and in combination, on the freshwater crayfish Pontastacus leptodactylus. In this study, the crayfish were exposed to PE-MPs (0.0, 0.5, and 1 mg L−1) and CuSO4·5H2O (0.0, 0.5, and 1 mg L−1) for a period of 28 days. Next, multi-biomarkers, including biochemical, immunological, and oxidative stress indicators were analyzed. Results showed that co-exposure to PE-MPs and CuSO4 resulted in increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and decreased alkaline phosphatase (ALP), butyrylcholinesterase (BChE), and gamma-glutamyl-transferase (GGT). Triglycerides, cholesterol, glucose, and albumin content also increased. Although no significant change was observed in lysozyme and phenoloxidase activities in crayfish co-exposed to 0.5 mg L−1 MPs and 0.5 mg L−1 CuSO4, their activities were significantly decreased in other experimental groups. Oxidative stress parameters in hepatopancreas indicated increased superoxide dismutase (SOD), glutathione peroxidase (GPx), and in malondialdehyde (MDA) levels, but decreased catalase (CAT), glucose 6-phosphate dehydrogenase (G6PDH), and cellular total antioxidant (TAC). Results showed that the sub-chronic toxicity of CuSO4 was confirmed. The study confirmed the toxicity of CuSO4 and found that higher concentrations led to more severe effects. Co-exposure to PE-MPs and CuSO4 primarily compromised the endpoints, showing increased toxicity when both pollutants were present in higher concentrations. The activities of POX, LYZ, ALP, GGT, LDH, and CAT were suppressed by both CuSO4 and MPs. However, a synergistic increase was observed in other measured biomarkers in crayfish co-exposed to CuSO4 and MPs.

Comparison of exoskeleton microbial communities of co-occurring native and invasive crayfish species

Host-associated microbial communities are an important determinant of individual fitness and have recently been highlighted as one of the factors influencing the success of invasive species. Invasive hosts introduce their microbes into the new environment, and then both the host and its associated microbes enter into a series of interactions with the native macroscopic and microscopic biota. As these processes are largely unexplored, we aimed to compare the exoskeletal microbial communities of co-occurring and phylogenetically related crayfish: the native narrow-clawed crayfish Pontastacus leptodactylus and the invasive signal crayfish Pacifastacus leniusculus from the recently invaded Korana River, Croatia. The results of high-throughput 16S rRNA sequencing showed that the exoskeletal microbiome of both species is very diverse, significantly influenced by the local environment and dominated by low abundance bacterial families from the phylum Proteobacteria. Furthermore, the exoskeletal microbiomes of the crayfish species differed significantly in the composition and abundance of Amplicon Sequence Variants (ASVs), suggesting that they are to some extent shaped by species-specific intrinsic factors, despite sharing a common habitat. However, over 95% of the bacterial genera associated with the exoskeleton were detected in the exoskeleton samples of both native and invasive crayfish. We paid particular attention to two known crayfish pathogens, Aphanomyces astaci and Saprolegnia parasitica, and find that both species carry low amounts of both pathogens. On the side, we find that a non-standard ddPCR protocol outperforms standard qPCR test for A. astaci under low concentration conditions. Taken together, our results indicate the possibility of bidirectional mixing and homogenisation of exoskeleton microbiome. As such, they can serve as a baseline in future detangling of the processes that act together to shape the microbiomes of co-occuring native and invasive congeners during biological invasions.

Динамика промысла и популяционных характеристик раков в озере Мостовое Алтайского края

The long–toed crayfish Pontastacus leptodactylus (Eschscholtz, 1823) is the only object of freshwater commercial invertebrates living in the lake. Bridge of the Altai Territory. This paper presents the dynamics of crayfish production (catch) by organized fishing in the period 2010-2022. A review of changes in the state of the cancer population in terms of size, mass and sexual structure was carried out. The characteristic of the reasons for the change in the fishing stock and the assessment of its current state are also given.

Phylogeographic patterns of genetic diversity in Pontastacus leptodactylus (Decapoda: Astacidae): is the hypothesis of the taxonomically rich genus Pontastacus true?

Abstract The narrow-clawed crayfish Pontastacus leptodactylus is a large native European astacid crayfish species distributed in the drainage area of the Azov, Black and Caspian Seas. The species shows immense morphological diversity across its range. Various species and subspecies have been described and, recently, eight species and two subspecies were confirmed in the updated classification of freshwater crayfishes. However, genetic diversity studies of the species are scarce, mostly from limited geographical areas. Therefore, we aimed to analyse the genetic diversity of this species using mtDNA and nuDNA from across their distributional range to verify the presence of described species. Analyses of individuals from 65 populations and 14 countries confirmed the existence of three divergent mtDNA phylogroups corresponding to the geographical area of Central and Southern Europe, Eastern Europe and Asia, and Turkey. Analysis of ancestral ranges revealed the Black Sea basin as the most likely area of origin. The nuDNA analysis showed low diversity partially corresponding to the mtDNA pattern. All analyses showed mitonuclear discordance indicating the existence of a single species. Therefore, we point out the possibility of taxonomic inaccuracy with the current number of valid species within the P. leptodactylus species complex.

Populations of long-clawed crayfish Pontastacus leptodactylus: Effect of commercial fishing on the size and age structure

Fishing affects the population of crayfish, while it changes the size and age characteristics. The size and age parameters of two populations of the narrow-clawed crayfish Pontastacus leptodactylus in the Loktyshi (Brest Region) and Krasnoslobodskoe (Minsk Region) reservoirs in Belarus have been compared. The Krasnoslobodskoye reservoir is intensively exploited with an annual catch of 3–4 tons of crayfish. There is no commercial fishing in the Loktyshi reservoir. Studies show that the average size of individuals in an intensively exploited population is smaller in comparison with a population where there is no commercial fishing for crayfish. Since crayfish fishing is regulated by a commercial measure (10.5 cm of total length) in intensively exploited populations, the average sizes of individuals are close to these limiting values. The life expectancy of crayfish is somewhat higher in the Loktyshi reservoir, where only amateur crayfish fishing is noted. Intensive fishing increases the mortality of females, whose annual survival rate is 37 %, while in the absence of fishing, the survival of females increases up to 57 %. The annual survival rate of males is 41–49 %. The fishing pressure leads to decrease in the survival rate of individuals and disappearance of crayfish aged 9–10 years from the population.

Fecundity of the narrow-clawed crayfish Pontastacus leptodactylus in the water bodies of Belarus

Pre-larvae hatching fecundity and ovarian fecundity of narrow-clawed crayfish populations were estimated in the lakes and reservoirs of Belarus. Statistically significant differences in the fecundity of females from various water bodies were noted only for Lake Kichino. For all other water bodies, the fecundity dependence on the length of females did not differ statistically and was described by one equation. The greatest loss of eggs was noted during the spawning period (oviposition), insemination and attachment to pleopods of the female. During this short period (2–3 hours), egg mortality of females 120 mm TL is 30 %, it decreases for small females and increases for large ones. During the gestation period, egg mortality averages 8 %.

Состояние популяций, запасов и промысла раков в водоемах Алтайского края в период 2010-2021 годов

The long-toed crayfish Pontastacus leptodactylus Eschscholtz is one of the few invertebrates of freshwater reservoirs of the Altai Territory, representing a promising object of fishing. This paper provides an overview of changes in the state of cancer populations in commercial reservoirs of the Altai Territory in the period 2010-2021. The analysis of the dynamics of the main parameters reflecting the quantitative characteristics of cancer populations was carried out. The trend of decline in commercial stocks of cancer is traced, the dynamics of production (catch) of cancer by organized fishing is presented. The characteristic of the main causes of changes in commercial stocks of cancer, both natural and anthropogenic significance, is given.

Comparative transcriptome sequencing analysis of the narrow-clawed crayfish Pontastacus leptodactylus (Eschscholtz, 1823) and discovery of candidate sex-related genes

The comparative analysis of the gonads transcriptomes of the narrow-clawed crayfish Pontastacus leptodactylus were conducted to screen for sex-differentiation related genes based on Illumina RNA-seq technology. The transcriptome sequencing of cDNA libraries generated 543 million clean reads, and the N50 and mean length of the identified 59,348 unigenes were 1205 and 746 bp, respectively. A total of 4875 differentially expressed genes (DEGs) were obtained between the two sexes, of which 1627 predicted to be up-regulated in ovaries and 3248 in testes. A total of 86 candidate genes known to be associated with sexual differentiation and development were searched in the transcriptome of P. leptodactylus. Our results showed that the highly expressed male-related genes (dmrt1, amh, gsdf, spata 1, spata 13, spata 2, srm and smox) were significantly up -regulated to a substantial degree, suggesting the potential roles of these genes in gonads of P. leptodactylus. In addition, 11,989 potential simple sequence repeats (SSRs) and 190,655 putative single nucleotide polymorphisms (SNPs) were detected. The putative DEGs between the gonads provide an important source of information for further study of the sex-differentiation related genes in P. leptodactylus as well as development of molecular markers.

Effects of methyl farnesoate injection on spermatozoa number and reproductive indices in the narrow-clawed crayfish Pontastacus leptodactylus

In this study, the effect of methyl farnesoate (MF) injection on haemolymph MF levels, spermatozoa production and the reproductive indices of gonadosomatic index (GSI), testicular index (TI) and vasosomatic index (VSI) were investigated in males of Pontastacus leptodactylus (Escholtz, 1823). Sixty male P. leptodactylus were used for the study. They were housed in a total of twelve tanks in their normal reproductive season in 2018 and were fed ad libitum with a pelleted food. Animals were injected once a week for five consecutive weeks, at doses of 250 (G2), 500 (G3) and 1000 (G4) ng MF g-1 of body weight. The doses of the injections, the durations used, and the frequency of administration were determined according to the literature. An increase was observed in gonadosomatic index and spermatozoal number of crayfish injected with 1000 ng of MF g-1 of body weight when compared to control (G1, no MF injection applied) and other experimental groups. In addition, the present study indicated that G4 crayfish had a higher GSI, TI and VSI than control crayfish. There was no difference in the level of hemolymph MF between control and MF injected crayfish. In conclusion, MF injection is effective for inducing increased gonadasomatic index and spermatozoal number in P. leptodactylus.

Effect of feed supplementation with effective microorganisms (em) bokashi onhepatopancreas and gut histology, growth performance, and survival rate of freshwatercrayfish Pontastacus leptodactylus (Eschscholtz, 1823)

A sixty-day feeding trial was conducted to investigate the effect of dietary effective microorganisms (EM) Bokashi on organ histology, growth performance, and survival rate of freshwater crayfish Pontastacus leptodactylus (Eschscholtz, 1823). Bokashi serum and powder consisted of two major microorganisms as Bacillus amyloliquefaciens spp. plantarum and Lactobacillus plantarum. Four treatment groups were established in control (without bokashi), bokashi powder 1% and 5% supplemented to diets. Bokashi serum was added at a ratio of 0.01% (v/v) of the total volume of the tank water once a week into which there was a constant flow of fresh water at a flow rate of 1.2 L min$^{-1}$. The crayfish were fed ad libitum with treatment diets for 60 days. The results showed that there was no significant difference in growth performance among the groups, but survival rates were significantly different between groups (p < 0.05). As a result of the microscopic examination of the intestine, pathological changes such as inflammatory cell infiltrations in the interstitial tissue, and lack of B, F, and R epithelial cells were found in the groups that were supplemented with bokashi while the control group exhibited normal tissue histology. As a result of this study, the addition of nonindustrial bokashi to crayfish diets had no effect on growth. In addition, nonindustrial bokashi products supplementation to crayfish diets caused severe pathological findings in hepatopancreas and

Disturbance in invasion? Idiopathic necrotizing hepatopancreatitis in the signal crayfish Pacifastacus leniusculus (Dana, 1852) in Croatia.

As the most successful crayfish invader and possible vector for infectious agents, signal crayfish Pacifastacus leniusculus is among the major drivers of the native crayfish species decline in Europe. We describe histopathological manifestation and frequency of newly detected idiopathic necrotizing hepatopancreatitis along the invasion range of the signal crayfish in the Korana River in Croatia. Our results show extremely high prevalence of necrotizing hepatopancreatitis (97.3%), with 58.9% of individuals displaying mild and 31.5% moderate histopathological changes in the hepatopancreas, also reflected in the lower hepatosomatic index of analysed animals. Recorded histopathological changes were more frequent in the invasion core where population density is higher. Our preliminary screening of co-occurring native narrow-clawed crayfish Pontastacus leptodactylus showed lower incidence (33.3%) and only mild hepatopancreatic lesions, but potentially highlighted the susceptibility of native crayfish populations to this disease. Pilot analyses of dissolved trace and macro elements in water, sediment fractions and crayfish hepatopancreas do not highlight alarming or unusually high concentrations of analysed elements. Hepatopancreas microbiome analysis, using 16S rRNA gene amplicon sequencing, identified taxonomic groups that should be further investigated, along with impacts of the disease on health and viability of both invasive and native crayfish populations.

Effects of serotonin (5‐HT) on juvenile culture of narrow‐clawed crayfish Pontastacus leptodactylus (Eschscholtz, 1823)

Serotonin was used for the first time in this study as a feed additive in juvenile freshwater crayfish Pontastacus leptodactylus, (stage II-V) to investigate its effects on growth performance, survival and immune response based on total haemocyte count (THC). Serotonin was included in diets at levels of 0 (control), 5, 10, 20 and 40 mg kg−1. When the results were examined, a significant quadratic increase was observed in the values of final total length: FTL and final body weight: FBW, weight gain (WG), length gain (LG) and specific growth rate (SGR) with dietary serotonin amounts (Plinear and Pquadratic <0.05). The survival rates of crayfish showed a significant linear increase with doses of serotonin (Plinear = 0.001). THC values, on the other hand, were not affected by serotonin amounts in experimental diets. The broken line models estimated optimum dietary serotonin inclusions based on FBW and FTL as 20.03 and 20.44 mg kg−1, respectively. In conclusion, dietary serotonin can be used in growing juvenile P. leptodactylus during the developmental stages of II-V.

Role of river crayfish Pontastacus leptodactylus (Esch.) in maintaining the stability of freshwater bodies in Eurasia

The role of the long-toed crayfish (Pontastacus leptodactylus leptodactylus) in the hydrocenosis of a water body in the floodplain of the Rutka River, one of the tributaries of the Middle Volga, was studied in order to determine an ecologically grounded catch rate. During the study period, the population of P. l. leptodactylus had a high productivity and occupied the dominant status in the biocenosis among the components of animal origin. The amount of plant biomass consumption in summer by juveniles and sexually mature crayfish was calculated. Zoobenthos is consumed in relatively small quantities by all age groups of the crayfish population; zooplankton – by underyearlings. The consumption of aquatic vegetation by crayfish determines the importance of their role in restraining its growth and in limiting the eutrophication of the water body. The biomass of the P. l. leptodactylus population was calculated. It must always be present in the water body to maintain the stability of its biocenosis, which is possible if the annual catch of crayfish is limited to 10-15% of their commercial stock.

Molecular identification of burn spot disease syndrome agent Fusarium avenaceum in Turkish crayfish Pontastacus leptodactylus populations.

In this study, we aimed to isolate and identify the causative agent of burn spot disease syndrome from crayfish populations within Turkish water bodies. Crayfish Pontastacus leptodactylus samples were captured from Bayramşah Reservoir, Karaidemir Reservoir and Keban Reservoir (Turkey). Fungi samples were taken from symptomatic crayfish and cultured in potato dextrose agar, and DNAs were extracted. Species-specific PCR primers (FAF1 and FAR) were used in order to amplify the internal transcribed spacer (ITS) region of fungal DNA. Sequences obtained from the amplified regions were analyzed using GenBank and identified. As a result, a molecular diagnosis of the fungi samples was made, and the pathogen was identified as Fusarium avenaceum. In addition, a challenge test with healthy crayfish was conducted to evaluate the pathogenicity of the fungi. F. avenaceum was reisolated from experimentally infested individuals, and thusly we confirmed the disease. It was concluded that F. avenaceum causes burn spot disease syndrome in P. leptodactylus.

Detection of fish pathogen Saprolegnia parasitica in environmental DNA samples by droplet digital PCR

Oomycetes are fungal-like microorganisms parasitic towards a large number of plant and animal species. Genera from order Saprolegniales, such as Saprolegnia and Aphanomyces, cause devastating infections of freshwater animals. Saprolegnia parasitica is a widely distributed oomycete pathogen that causes saprolegniosis, a disease responsible for significant economic losses in aquaculture, as well as declines of natural populations of fish and other freshwater organisms. Despite its negative impact, no monitoring protocol for S. parasitica has been established to date. Thus, we aimed to develop a droplet digital PCR (ddPCR) assay for the detection and quantification of S. parasitica in environmental DNA samples. Saprolegnia parasitica-specific primers were designed to target internal transcribed spacer region 2 (ITS 2), based on the alignment of ITS sequences of S. parasitica and a range of Saprolegnia spp., as well as other oomycetes. The specificity of primers was tested using genomic DNA of S. parasitica (as positive control) and DNA of non–S. parasitica oomycete isolates, as well as trout/crayfish DNA (as negative control). The primers specifically amplified a segment of the ITS region of oomycete pathogen S. parasitica, while no amplification (i.e. no positive droplets) was obtained for closely related Saprolegnia spp. (e.g. Saprolegnia sp. 1 and S. ferax) and other more distantly related oomycetes. Next, the limit of detection (LOD) of the assay was established by using serial dilutions of the S. parasitica genomic DNA. The determined sensitivity of the assay was high: LOD was 15 fg of pathogen’s genomic DNA per µL of the reaction mixture. Assay performance was further assessed with environmental DNA samples isolated from water from the trout farms and natural environments, as well as (ii) biofilm from the host surface (swab samples). Water samples were collected from 21 different locations in Croatia, while swab samples were collected from S. parasitica host/carrier species: (i) skin and eggs of the rainbow trout (Oncorhynchus mykiss Walbaum, 1792) and brown trout (Salmo trutta Linnaeus, 1758), and (ii) cuticle of signal crayfish (Pacifastacus leniusculus Dana, 1852) and narrow clawed crayfish (Pontastacus leptodactylus Eschscholtz, 1823). Samples were classified into agent levels A0 to A6, depending of the number of S. parasitica ITS copies per ng of total DNA. Saprolegnia parasitica was detected in 76 % of water samples (16/21) and the range of pathogen’s ITS copies in positive samples was between 0.02 and 14 copies/ng of total DNA (agent levels A1 to A3). Regarding the swab samples, S. parasitica load was significantly higher in diseased trout than in those with healthy appearance: 9375 vs 3.28 S. parasitica copies/ng of total swab DNA (average agent level A6 vs. A2, respectively). Despite the fact that none of the sampled crayfish had signs of infection, the pathogen was detected in all tested cuticle swabs. Swabs of P. leniusculus, a known S. parasitica host, had significantly higher S. parasitica load than swabs of P. leptodactylus, S. parasitica carrier: 390 vs 83 S. parasitica copies/ng (agent level A5 vs. A4, respectively). In conclusion, our results demonstrate the applicability of the newly developed ddPCR assay in monitoring and early detection of S. parasitica in aquaculture facilities and natural freshwater environments. This would help in a better understanding of S. parasitica ecology and its effects on the host populations.

Only one can remain? Environmental and spatial factors influencing habitat partitioning among invasive and native crayfishes in the Pannonian Ecoregion (Hungary)

Biological invasions have increasingly threatened indigenous species, influence metacommunity organisation and consequently, global biodiversity. World-wide expansion of non-indigenous crayfish (NICS) is associated with dramatic changes in species poor indigenous crayfish (ICS) assemblages challenging conservation planning. We analysed long-term changes of crayfish occurrences from the pre-invasion state, through the first appearance of NICS, to their intensive spread in Hungarian waters. Further, we analysed present-day crayfish metacommunity patterns for co-occurrences and influence of spatial and environmental factors. Historic data revealed a marked pre-invasion decline in indigenous noble crayfish Astacus astacus and stone crayfish Austropotamobius torrentium populations, but not in the narrow-clawed crayfish Pontastacus leptodactylus. Historic data provided no direct evidence for the impact of NICS on ICS, rather it supported that NICS often entered areas where ICS had been extinct or were not present at all. Crayfish species extremely rarely co-occurred which could indicate their strong competition and be related to utilization of empty sites by NICS. Crayfish metacommunities were predominantly spatially structured indicating the primary influence of ongoing invasion. Crayfish species also exhibited different environmental preferences mainly along the altitude and temperature gradients. We conclude that the invasion is still in the expanding phase and without an effective conservational program the future of ICS is doubtful in Hungary. Conservation policy should focus on the preservation and reintroduction of the stone and noble crayfishes in highland refugees. Expansion of NICS should be prevented in refugee areas by utilizing possibilities provided by natural and artificial barriers, and education and strict ban should be simultaneously applied to prevent further illegal releases by aquarists.

New records and disappearance from old sites of narrow-clawed crayfish Pontastacus leptodactylus in northwestern Russia

New records and disappearance from old sites of narrow-clawed crayfish Pontastacus leptodactylus in northwestern Russia

Fusarium oxysporum causes black gill disease in narrow-clawed crayfish Pontastacus leptodactylus.

Morphological and molecular analyses were carried out to determine the causative agent of black gill disease in narrow-clawed crayfish Pontastacus leptodactylus specimens collected from 6 lakes (Taşkısığı, Beyşehir, Karaidemir, Karataş, Manyas, and Gölhisar) in Turkey. Fungi were isolated from the tissues of crayfish displaying putative black gill disease symptoms. Morphological evaluation was conducted, and the isolates were determined to be similar to Fusarium oxysporum. Subsequent molecular cloning of the ITS region of nrDNA by PCR confirmed species identification; DNA sequences from all 6 isolates were 99% similar to those of F. oxysporum. An experimental infection trial was conducted in triplicate using 1 of the 6 isolates to fulfill Koch's postulates. Three groups of crayfish were used: (1) wounded and contaminated (WC), (2) wounded and not contaminated (WNC), and (3) non-wounded and contaminated (NWC). On Day 3, one individual died in the WC group. Throughout the total 74 d monitoring period, no other mortality was recorded. On Day 14, all crayfish in the WC group showed blackened gills, whereas all crayfish in the NWC displayed partial blackening and all crayfish in the WNC group displayed normal gill coloration. F. oxysporum was re-isolated in pure culture from the WC and NWC groups; thus, the disease was confirmed. Our results indicated that F. oxysporum causes black gill disease in P. leptodactylus crayfish. Moreover, we demonstrated that F. oxysporum can also infect non-wounded crayfish.

Protein and amino acid composition of wild caught freshwater crayfish (Pontastacus leptodactylus) in the reproductive season

Interest in feeding crayfish under culture conditions has increased in the last few years; however, there is still a lack of information on feeding crayfish according to their nutritional requirements (i.e., protein and amino acid dietary demands of broodstock). In this study, the protein and amino acid composition of abdominal muscle, gonads and hepatopancreas of male and female broodstock crayfish Pontastacus leptodactylus (Eschscholtz, 1823) were determined in the reproductive season. The results show that in P. leptodactylus, the amount of protein in the ovary was 47.25 mg/g and that it was 35.03 mg/g and 39.36 mg/g in the testes and vasa deferentia, respectively. In males, the values of essential amino acids (EAA) obtained in the abdominal muscle were significantly lower than those obtained from the hepatopancreas, testes and vasa deferentia (P < 0.05). In female crayfish, EAA/total amino acids (TAA) were found to be 45.48 % in the ovary, which is significantly higher than that of the abdominal muscle (40.19 %) and hepatopancreas (42.14 %) (P < 0.05). The results also show that abdominal valine, threonine, lysine, and histidine were statistically higher in female crayfish than male crayfish (P < 0.01). Leucine was the major EAA found in males in abdominal muscle (8.73 %). In conclusion, this study analyzed the protein and amino acid composition of abdominal muscle, hepatopancreas and gonad of crayfish in the breeding season in order to understand the protein and amino acid contents of wild caught crayfish and get an idea on the nutritional requirements of P. leptodactylus in the reproductive season.

First Report of Albinism in Turkish Crayfish Pontastacus leptodactylus (Eschscholtz, 1823) (Crustacea, Decapoda, Astacidae)

A female albino crayfish Pontastacus leptodactylus (Eschscholtz, 1823) was captured from Atikhisar Reservoir in Çanakkale, Turkey on July 18, 2020. The albino crayfish is lacked melanin that is normally found on normal crayfish. The compound eyes of the albino crayfish were black as in normal crayfish. Morphometric characteristics were measured and the total length was 101.98 mm, carapace length was 50.04 mm, carapace width was 26.56 mm and weight was 35.90 g. Albinism is a widespread disorder in the animal kingdom and is triggered by the absence of melanin in the skin, eyes, or hair. Investigation on albinism has commonly focused on mice and humans. Therefore, there is restricted research on albino crayfish. In the present paper, the occurrence of albinism in crayfish is firstly reported from Atikhisar Reservoir in Çanakkale, Turkey. Therefore, this paper significantly contributes to the scientific literature by providing the first knowledge on the presence of albino crayfish in the Atikhisar Reservoir, Çanakkale, Turkey.