Abbottina Rivularis Research Articles

Relationship between fish traits and the methane‐derived carbon contribution to fish in a shallow lake

Abstract Although the transfer of methane‐derived carbon (MDC) to benthic macroinvertebrates such as chironomid larvae and oligochaetes has been well documented, knowledge of the transfer of MDC to fish is limited. We investigated the MDC contribution to 28 fish species through their growth stages and examined the relationship between fish traits including body size, and MDC contribution to fish within species in Lake Kasumigaura, Japan. We used carbon stable isotope ratios and a two‐source mixing model (methane‐oxidation bacteria [MOB] and particulate organic matter) to estimate the MDC contribution to fish. The MDC contribution to individual fish ranged from 0% to 21.5%. Anguilla japonica showed the highest MDC contribution (mean 3.8%). Fish species were classified into four groups according to two criteria: (a) whether the correlation between the MDC contribution and fish size (within species) was significantly negative (negative vs. not significant; ns); and (b) whether the 90th percentile of MDC contribution was 0% or not. The mean MDC contribution was highest (2.18% ± 2.93%, 12 species) for the group with (a)ns/(b)>0%, including the high contribution species such as Abbottina rivularis (mean 5.5%) and Biwia zezera (mean 9.8%). This group (12 species) included relatively high numbers of benthic habitat use (eight species) and omnivores (nine species). The mean MDC contributions were almost zero for the group with (a)ns/(b)=0% (seven species), which included only two species of benthic habitat use and one species of omnivores. The mean MDC contributions were intermediate for the other groups with (a)negative/(b)>0% (1.30% ± 1.17%, seven species) and (a)negative/(b)=0% (0.10%, two species). The negative correlation between fish size within species and MDC contribution in groups with (a)negative/(b)>0% and (a)negative/(b)=0% indicated that ontogenetic habitat and dietary shifts induced changes in MDC transfer. Our results suggest that 21 out of 28 fish species were involved in the MDC transfer in a shallow lake, but variation in MDC transfer could be explained by fish traits (trophic guild and habitat use). Although the mean MDC contribution to all fish species was low (0.61% ± 1.97%), the roughly estimated annual consumption rate of fish on MOB corresponded to approximately 10% of the MOB production in the sediment, suggesting that fish contribute to methane dynamics from the perspective of biogeochemical cycles.

Diversity of the ichthyofauna in small rivers of the northern macro-slope of Saur-Tarbagatai (Central Asia)

Studying the fish composition of small rivers and streams allows us to understand the diversity of species, their ecology, and the interrelationships in the ecosystem. Monitoring of these species can help in assessing the state of aquatic ecosystems and identifying potential problems. This paper shows the results of fish diversity studies of in 12 rivers flowing on the northern slope of the Saur-Tarbagatai Mountains. The study of fish diversity of 12 rivers in 2023 showed the presence of 10 species, representing native and alien ichthyofauna of Kazakhstan. The highest fish diversity was found in the Saryeshki river and the Kendirlik river. Only one fish species is represented in the rivers Zhinishkesu and Sarybulak. The dominant species in numbers are Siberian gudgeon, stone loach, European minnow, Chinese false gudgeon and naked osman. Aboriginal species spined loach is the least represented in all water bodies encountered, and as of 2023 it can be classified as a rare native fish.

The feeding habits of the Amur whitefish Coregonus ussuriensis in the Amur River, China

To study their feeding habits, Coregonus ussuriensis samples were collected seasonally in the Amur River, China. A total of 574 samples were collected, including 200 individuals with empty stomachs. The stomach contents of the remaining 374 samples were identified, counted, weighed, and analyzed. The results showed that the vacuity rate of Coregonus ussuriensis was 34.84% in total; the rates in summer and autumn were higher than in spring and winter. Prey items could be divided into three categories: fish, benthos, and mammals, with 62 taxonomic units. Of these, fish had the highest relative importance index (IRI), followed by benthos and mammals. Specifically, Exopalaemon modestus was the dominant species among the food species of Coregonus ussuriensis, and unidentified fish, Hydropsyche sp., Hemiculter leucisculus, Abbottina rivularis, and Saurogobio dabryi were important species. The average repletion index (RI, %) of Coregonus ussuriensis was highest in autumn (1.86), followed by winter (1.40), summer (1.26), and spring (1.02). The main food of Coregonus ussuriensis was benthos in spring and autumn, and fish in summer and winter. Cluster analysis showed that, according to the similarity level of the bait biological composition, the fork length group samples of Coregonus ussuriensis could be divided into three groups: 210–330 mm, 330–450 mm, and >450 mm. The highest IRI% of feed organisms in these three groups of samples were fish (73.67%), benthos (75.12%), and benthos (94.46%), respectively. It can be observed that with the growth of the fork length of Coregonus ussuriensis, the importance of benthos in its diet increases. The results of an RDA analysis on the relationship between main bait organisms and various factors indicated that season, river level, river width, and fish size have a significant impact on bait organisms and a positive or negative impact on the quality scores of some bait species. This study filled the gap in biological research on the feeding ecology of Coregonus ussuriensis and laid a research foundation for ecological research on this species and its resource protection and aquaculture.

Length-Weight Relationships for Ten Fish Species from Rivers in the Qinling Mountains, China

Length-weight relationships (LWRs) were reported for ten fish species (Abbottina rivularis, Hemibarbus labeo, Hemibarbus maculatus, Onychostoma macrolepis, Opsariichthys bidens, Rhynchocypris lagowskii, Schizothorax prenanti, Sinibrama macrops, Zacco platypus, and Siniperca scherzeri). Fishes were collected from 62 sampling stations covering an area of ∼7000 km2 in the Qinling Mountains, characterized by unique fauna and distribution pattern, using gillnets and ground cages during June to December 2022. The intercept a ranged from 0.013 for S. prenanti to 0.060 for H. labeo, and the slope b ranged from 2.537 for H. labeo to 3.079 for Z. platypus.

Distribution and morphobiological characteristics of the chinese false gudgeon Abbottina rivularis (Basilewsky, 1855) in the Ile river basin (Balkhash basin, Republic оf Kazakhstan

As a result of intentional and accidental introduction of alien fish species in most reservoirs of Southern and South–Eastern Kazakhstan, there was a significant change in the composition of the ichthyofauna. Alien low-value fish species have become numerous in many small reservoirs of the basin. In 2019-2021, the distribution of the river abbottina Abbottina rivularis (Basilewsky, 1855) was studied in several small reservoirs of the Ile River basin. The purpose of the research: to study the morphobiological characteristics of two populations of river abbotina in the basin of the Ile and give an assessment of their condition. Biological and morphological analyses of samples were carried out according to the most common scheme. The variability of 33 plastic and 7 counting features of two samples was studied. An indicator of fluctuating asymmetry was used to assess the conditions of existence. As a result of morphometric measurements of fish, out of 20 indicators of plastic measurements, significant changes were found in 9 (45%) plastic signs compared to the mother reservoir. In fish, the antedorsal distance (aD) increased by 6%, the length of the dorsal fin base (lD) by 25%, the height of the dorsal fin (hD) by 6.3%, the length of the anal fin (lA) by 51.4%, the length of the pectoral fins (lP) by 10.8%, the length of the ventral fin (lV) increased by 18%. The length of the head (c) increased by 11.2%, the highest body height (H) decreased by 5.3%, the lowest body height (h) increased by 26.4%. Despite significant violations of homeostasis in development, fish in ponds reach large sizes.Тhe Bakanas irrigation irrigation system can be a supplier of juvenile river abbotina for the Ile River. The size and weight indicators of the studied populations of the river abbotina from two samples showed lower values when compared with similar data from the Issyk River (1975) and the mother reservoir of the Amur River (1956). Key words: acclimatization, alien species, river abbotina, Balkhash – Ili basin, small reservoirs, morphometric characteristics, fluctuating asymmetry.

Abbottina rivularis (Chinese false gudgeon)

This datasheet on Abbottina rivularis covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Impacts, Prevention/Control, Further Information.

Complete mitochondrial genome characterization of Cirrhinus mrigala from the Three Gorges Reservoir in China

Cirrhinus mrigala is a fish introduced from India to the south China in 1980s, and a large number of this species is found in the Three Gorges Reservoir of the upper Yangtze River now, which might pose a great threat to the indigenous fish. In this study, we sequenced and characterized the complete mitochondrial genome of C. mrigala from the Three Gorges Reservoir. The complete mitochondrial genome was 16,595 bp in length and contained 13 protein-coding genes (PCGs), two ribosomal RNA genes (12S rRNA and 16S rRNA), 22 transfer RNA genes (tRNA) and one non-coding control region (D-loop). The overall nucleotide composition was 32.05% (A), 24.48% (T), 15.49% (G) and 27.98% (C). The phylogenetic tree indicated that C. mrigala was related to Sinilabeo rendahli, Abbottina rivularis and Pseudogyrinocheilus prochilus. The results can provide basic genetic information for subsequent population genetic and phylogenetic researches, which will be helpful for understanding the genetic resource dynamic of C. mrigala in areas outside of its native distribution.

Characteristics of Fish Fauna Data in jin Island, Korea

The fish community in the Jin Island (Jindo, Jisan, Munnae, Yulri, 1/25,000 scale) was investigated with the data collected through the 3rd National Ecosystem Survey from April to October in 2012. During the period, 25 species belonging to 7 families were collected. There were 11 biological resources subject to the approval of outbound transfer, including Squalidus gracilis majimae, Abbottina rivularis, Aphyocypris chinensis, Hemiculter eigenmanni, Rhodeus ocellatus, Iksookimia hugowolfeldi, Iksookimia koreensis, Trachidermus fasciatus, Monopterus albus, Macropodus ocellatus and Oryzias latipes. The dominant species was Pseudorasbora parva(26.3%), and the subdominant spaecies was Carassius auratus(16.0%).</br>Background: In Korea, from 1989 National Ecosystem Survey (NES) was conducted by ministry of environment for every 10 years to cover whole south Korea in 1/25,000 scale. The scope of NES including 8 taxa – vegetation, plant, fish, macro invertebrate, insect, birds, amphibian & reptile, mammal and geomorphology. With the results of ecosystem survey we build up species and ecosystem database based on GIS environment. Ecosystem database is becoming very necessary to understand origins and relationship between human and nature and also to reduce ecosystem disturbance.</br>New information: An ecological information platform can play important roles as a computing system to collect knowledge, distributed research findings and separated data from researchers. We designed and developed ecological information portal service (EcoBank 1.0) for collecting and providing ecological information for various stake-holders. Then, we developed basic functions to analyze ecosystem for each stake-holders (researchers, general public and policy makers). We successfully designed a computing system named EcoBank supporting the functions of Digital Object Identifier (DOI) publish and data quality management.

Chromosomal study of Khawia abbottinae (Cestoda: Caryophyllidea): karyotype and localization of telomeric and ribosomal sequences after fluorescence in situ hybridization (FISH).

An original cytogenetic study combining classical karyotype analysis and modern fluorescence in situ hybridization using telomeric (TTAGGG)n and ribosomal sequences (18S rDNA) was performed in Khawia abbottinae (Cestoda, Caryophyllidea), a parasite of Chinese false gudgeon (Abbottina rivularis) from China. Analyses based on conventional Giemsa staining, DAPI, YOYO-1 dye, and silver (Ag) staining were also carried out. The karyotype is composed of eight pairs of metacentric and telocentric chromosomes (2n = 16, n=5m + 3t). Constitutive heterochromatin was mainly positioned at pericentromeric regions, and telomeric sequences (TTAGGG)n were restricted to the end of all chromosomes. In mitotic preparations stained with Giemsa, both homologues of chromosome pair 4 showed a distinct secondary constriction. FISH with rDNA probe confirmed that this secondary constriction contains a nucleolar organizer region (NOR). The process of spermatocyte meiosis and the dynamics of nucleolus degradation in dividing cell were scrutinized. The present study and its results enhance the limited knowledge on basic karyotype characteristics and 18S rDNA clusters location in caryophyllidean tapeworms.

Three complete mitochondrial genomes of freshwater fishes in the genus Abbottina (Cypriniformes: Gobionidae)

Abbottina binhi has been misidentified as Abbottina rivularis in China for a long time. In this study, we determined three mitochondrial genomes of A. rivularis and A. binhi such that these data should contribute to molecular identifications of the two species. The size of new mitochondrial genomes was 16,609 or 16,599 bp with A + T bias of 55.7–56.5% in the base compositions. Our reconstructed phylogeny showed that A. rivularis and A. binhi formed a sister taxon relationship, and they together were a monophyletic group.

Phylogeography of the Chinese false gudgeon, Abbottina rivularis, in East Asia, with special reference to the origin and artificial disturbance of Japanese populations

The Chinese false gudgeon, Abbottina rivularis, is a common cyprinid fish that is widely distributed throughout continental East Asia, but exhibits a restricted, discontinuous distribution in western Japan, including Honshu and Kyushu islands. In this study, analyses of mitochondrial (cytochrome b) and nuclear (glyt, myh6, and RAG1) genes were conducted to investigate patterns and magnitudes of intraspecific differentiation among A. rivularis populations in Japan and adjacent continental areas. Phylogenetic analysis of the mitochondrial gene sequences resolved four major lineages—the Japan lineage (JL), a northern continental lineage (NCL), and two southern continental lineages (SCL1 and SCL2)—with uncorrected pairwise sequence distances of 9.4–15.2% (estimated divergence times, 7.9–17.1 Myr). Two lineages (JL and SCL1) occurred in both the Honshu and Kyushu districts of Japan. Compared with populations in continental areas, most Japanese populations exhibited less genetic diversity. The JL was divided into two well-differentiated sub-lineages distributed on Honshu and Kyushu islands, respectively. Kyushu Island, as well as areas on Honshu where the species is known to have been introduced, also harbored the SCL1 lineage, which constituted most of the populations on Kyushu. The applied nuclear DNA data strongly suggest that hybridization between the Japan and continental lineages has occurred on Kyushu Island. The artificial introduction hypothesis, instead of a two-origin scenario, best explains the origin of the SCL1 in Japan.

Morphological and molecular characterization of the muscle-infecting myxosporean Myxobolus xinyangensis sp. nov. from Abbottina rivularis in China

During an environmental assessment on the Huang River in Xinyang City (Henan Province, China), a novel Myxobolus species (Myxozoa: Myxobolidae) was found infecting the trunk muscle of Chinese false gudgeon Abbottina rivularis Basilewsky, 1855 (Gobioninae, Cyprinidae). Plasmodia of the new myxozoan, nominated herein as Myxobolus xinyangensis sp. nov., are round and yellowish, symmetrically and bilaterally located dorsal to the openings of the 2 opercula, and measure about 4.5 mm in diameter. The mature myxospores are orbicular in frontal view and fusiform in sutural view, with slightly tapered anterior end and rounded posterior end, and measure 9.4 ± 0.5 (8.7-10.6) µm long, 8.6 ± 0.6 (7.3-9.5) µm wide and 6.4 ± 0.3 (5.8-7.1) µm thick (mean ± SD, range). The ratio of spore length to spore width is close to 1. Two slightly unequal pyriform polar capsules, with tapering anterior ends and rounded posterior ends, measure 5.6 ± 0.67 (4.3-6.8) µm long and 3.0 ± 0.3 (2.4-3.6) µm wide, present as a figure 8 in the anterior part of spores and tightly converge at the top end of spores. Polar filament coils show 4 to 5 turns and are situated perpendicularly to the longitudinal axis of the polar capsules. No intercapsular appendix or sutural folds at the posterior end of spores were observed. The obtained partial small subunit ribosomal DNA sequence did not match any available data in GenBank and showed the highest sequence identity (93%) with 2 cyprinid trunk muscle-infecting Myxobolus species, M. pseudodispar and M. klamathellus. Phylogenetic analysis clearly showed that M. xinyangensis sp. nov. clustered within a cyprinid trunk muscle-infecting Myxobolus subclade at the basal position, but as an independent branch which was a possible reflection of its distinct myxospore morphology. This is the first record of infection of Myxobolus species in the trunk muscle of Abbotina fish.

Low-head-dam fish culture effects on spatial-temporal patterns of local habitat and fish assemblages in the upstream and downstream of rivers

Fish assemblage will change along with the river habitat environment. In order to find the response degree of fish assemblage to fish culture within low-head-dam water,two low-head dams( including the upstream and downstream dams) of the Wulong River( a tributary of the lower reach of the Yangtze River,China) were selected as sampling sites,where the habitat variables,the fish diversity and fish assemblage structure were surveyed for 6 times from 2013 to 2014 in these wadeable reaches of the sampling sites. A total of 24 fish species which belong to 5 orders,21 genera and 24 species were caught,with dominant Cyprinidae accounting for 58. 3% of the total. After an analysis on the influences of temporal changes and local habitat conditions upon the fish assemblage,seasonal factors were found to have no apparent effect on the fish assemblage structure. The spatial location( the upstream dam or the downstream dam) affected the assemblage's structural differences significantly,which were determined by the abundance of Hemiculter leucisculus,Abbottina rivularis,Rhodeus sinensis,Acheilognathus macropterus in the upstream site,and the abundance of Gambusia affinis in downstream site. Besides,all the three habitat variables including dissolved oxygen,conductivity and current velocity exerted a great impact on the fish assemblage. The differences in habitat environment bring about some great influences on the fish assemblage,showing in the dramatic decrease of capture weight,quantity,density and diversity of fish in the sampling sites of the downstream dam,which are probably caused by the fish culture within the low-head dam.

Ichthyofauna of the Aksu River of Balkhash Basin

The Aksu River is one of the main rivers of Zhetysu (Seven Rivers) and flows into Lake Balkhash. The current ichthyofauna of the Aksu River is represented by seven indigenous and eleven alien species. The largest number of alien fish species are noted on a large part of the piedmont and estuary river sections. The structure and species composition of river fish populations have changed over the last 20 years. The Chinese false gudgeon Abbottina rivularis and the Siberian dace Leuciscus baicalensis have appeared in it, and the former has reached a substantial abundance. The species structure of fish populations in the piedmont part is extremely unstable and depends on its hydrological regime.

The complete mitochondrial genome of Chinese rod gugeon Abbottina rivularis (Cypriniformes, Cyprinidae)

In this study, the complete mitogenome sequence of the Chinese rod gugeon, Abbottina rivularis (Basilewsky, 1855) has been amplified. The mitogenome, consisting of 16,608 base pairs (bp), had the typical vertebrate mitochondrial gene arrangement, including 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs genes and a noncoding control region (CR). CR of 929 bp length is located between tRNAPro and tRNAPhe. The overall base composition of A. rivularis is 29.9% for A, 27.2% for C, 25.7% for T and 17.3% for G, with higher AT content of 55.6%. The complete mitogenome may provide rather essential and important DNA molecular data for further phylogenetic analysis for not only congeneric species but also higher different taxa of Cyprinid fishes.

Khawia abbottinae sp. n. (Cestoda: Caryophyllidea) from the Chinese false gudgeon Abbottina rivularis (Cyprinidae: Gobioninae) in China: morphological and molecular data

Khawia abbottinae sp. n. is described from the Chinese false gudgeon, Abbottina rivularis (Basilewsky) (Cyprinidae: Gobioninae), from the Yangtze River basin in China. The new species can be distinguished from the congeneric species mainly by the arrangements of the testes, which form two longitudinal bands (other congeneric species have the testes irregularly scattered throughout the testicular region) and their number (at maximum 85 testes versus at least 160 in the other Khawia spp.), and the morphology of the scolex, which varies from cuneiform to widely bulbate scolex, being separated from the remaining body by a short neck and possessing a smooth, blunt or rounded anterior margin. Other typical features of K. abbottinae are its small size (total length less than 1.5 cm) and body shape, with the maximum width at its first third. The distinct status of the new species was confirmed by molecular data (ssrDNA and ITS1 sequences). Phylogenetic analyses revealed a close relationship of the new species with K. rossittensis (Szidat, 1937) and K. parva (Zmeev, 1936), parasites of crucian carp and goldfish (Carassius spp.), but both species markedly differ from K. abbottinae in their morphology. Until now, five valid species of Khawia (K. abbottinae, K. japonensis, K. rossittensis, K. saurogobii and K. sinensis) have been reported from China.

Growth and habitat use of the Chinese false gudgeon, Abbottina rivularis, in an irrigation channel near the Ushizu River, northern Kyushu Island, Japan

Information on a population of Abbottina rivularis inhabiting an agricultural ditch was collected during field surveys and was analyzed for age, growth, and habitat use. Measurements of 1,035 individuals revealed that the population had two size classes, a maturation age of 1 year, and a lifespan of 1–2 years. On the basis of the growth pattern and life stage, we classified the life cycle of this species into four stages: the juvenile stage, the immature stage with rapid growth and with no growth, and the adult stage. Habitat use during each stage was analyzed with a generalized linear mixed model. The best fit models revealed that 3–5 environmental factors were important predictors of population size in each stage. In particular, the number of fish increased with increased variation in water depth and with smaller median particle size of the bottom substratum in all stages.

Spawning habitat of the Chinese false gudgeon, Abbottina rivularis, in an irrigation channel near the Ushizu River, northern Kyushu Island, Japan

Spawning habitat of the Chinese false gudgeon, <i>Abbottina rivularis</i>, in an irrigation channel near the Ushizu River, northern Kyushu Island, Japan

Spatial pattern of fish community in the Erhai Lake

The Erhai Lake is an extant production base of Yunnan province for aquatic products.Due to the environment and fishery pattern change,the fish fauna of the Erhai Lake are varied.How about the status? How about the fish community structure and its distribution? There are less typical reports till now.This study investigated species composition and abundance of fish at 21 sites in the Erhai Lake for two times in August and November 2009,respectively.The fish nets for each station at about 5:00 pm on the first day and harvested at 5:00 am on the second day.Three samples were conducted at each site for each sampling.Species composition and number of individuals,sampling time,environment factor,latitude and longitude of the sampling site,types of nets were recorded.The fishes were identified and classified.The data were analyzed and interpreted with diversity index(Shannon-Wiener index;Pielou index),similarity coefficient(Sorenson index;Bray-Curtis index) and various multivariate statistical methods(CLUSTER;MDS;ANOSIM;SIMPER).The results showed there were 23 species,belonging to 5 orders and 9 families.The fish community of Erhai Lake could be divided into three groups: alongshore community(CⅠ),open water community(CⅡ) and upstream community(CⅢ).Analysis of similarity(ANOSIM) and similarity of percentage(SIMPER) showed the differences among these groups were significant(R=0.735,P0.01).The indicator species of CⅠ were Hemiculter leucisculus,Carassius auratus,Pseudorasbora parva,etc.,and their contribution of similarity in CⅠ was 80.71%.The indicator species of CⅡ were Aristichthys nobilis,Hypophthalmichthys molitrix,Megalobrama amblycephala,etc.,and their contribution of similarity in CⅡ was 98.2%.The indicator species of CⅢ were C.auratus,P.parva,Acheilognathus elongates,etc.,and their contribution of similarity in CⅢ was 94.94%.The average contribution of dissimilarity between CⅠ and CⅡ was 76.8%,the discriminating species were H.leucisculus,A.nobilis,P.parva,etc.,and their contribution of dissimilarity was 88.63%.The average contribution of dissimilarity between CⅠ and CⅢ was 54.94%,the discriminating species were H.leucisculus,A.elongates,Abbottina rivularis,etc.,and their contribution of dissimilarity was 78.99%.The average contribution of dissimilarity between CⅡ and CⅢ was 91.62%,the discriminating species were P.parva,H.molitrix,A.nobilis,etc.,and their contribution of dissimilarity was 85.82%.The CⅠ and CⅢ were mainly composed of small sized fishes,and CⅡ was larger ones.In conclusion,the diversity in spatial structure of fish community reflected the environmental heterogeneity in Erhai Lake.

Gyrodactylus rivularae n. sp. (Monogenoidea: Gyrodactylidae) from Abbottina rivularis (Basilewsky, 1855) (Pisces: Cyprinidae) in Central China

Gyrodactylus rivularae n. sp. (Monogenoiea: Gyrodactylidae) is described from the fins and body surface of the Chinese false gudgeon, Abbottina rivularis (Basilewsky, 1855) (Pisces: Cyprinidae), in cold-water streams of the Qinling Mountains, central China. The new species morphologically resembles Gyrodactylus gobioninum Gusev, 1955, another species infecting A. rivularis, and Gyrodactylus gobii Shulman, 1953, infecting Gobio albipinnatus Lukasch, 1933, but is distinguished by longer hamuli. Sequence data (874 base pairs ) of the ribosomal DNA (rDNA) spanning the ITS-1, 5.8S and ITS-2 regions is unique within GenBank. A BLAST (Basic Local Alignment Search Tool) search identified species of Fundulotrema to have the highest overall similarity of 95–99%, followed by Gyrodactylus alexanderi Mizelle and Kritsky, 1967, and Gyrodactylus lotae Gusev, 1953, suggesting these species are all part of a clade within Gyrodactylus Nordmann, 1832 sensu lato.