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Digesta were collected from the intestines of seven species of bottom‐feeding fish to better understand the role of incidental ingestion of sediment in exposing fish to inorganic contaminants. A composite sediment tracer variable, based on concentrations of Co, Cr, Ni, Ti, V, and Y in digesta and in sediment, was calculated to estimate sediment content of digesta. Concentration factors (mg/kg in digesta divided by mg/kg in sediment) of eight elements of interest were linearly regressed on this tracer variable. The relative importance of sediment ingestion to oral exposure was quantified. Zinc, Cd, and Cu were ingested mainly from sediment‐free food. Arsenic, Cr, Ni, Al, and Pb, in contrast, were ingested mainly from sediment. As an example, 93% of the Ni in digesta from a brown bullhead (Ameiurus nebulosus) was from sediment and only 7% from food. Regressions of Al and Pb in digesta of suckers (Catostomidae) suggested an additional oral source, possibly from oxides coating biotic or abiotic surfaces. Overall, concentrations of 12 of 21 elements studied were positively correlated with sediment content (p < 0.005). Including sediment ingestion as a pathway for bottom‐feeding fish is essential for accurately estimating exposures in toxicological studies. Environ Toxicol Chem 2024;43:1036–1046. Published 2024. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Spawning migrations of fishes are common case studies for examining the magnitude of resource subsidies; however, no studies have evaluated this phenomenon in iteroparous migrations of the Catostomid (i.e. suckers) genus Moxostoma (i.e. redhorses). Fish resource subsidies are usually represented as nitrogen (N) and phosphorus (P), and migratory redhorses can deliver these nutrients via excretion and eggs. We evaluated whether redhorses deliver N and P subsidies to Brasstown Creek—a fourth‐order stream in the Southeastern US—during their spawning migrations. We measured individual‐level nutrient contributions from excretion and eggs and extrapolated those values to estimate nutrient contributions based on daily abundances of migratory redhorses. We compared daily nutrient inputs to daily nutrient exports to determine the potential for resource subsidies. We estimated 71.6 kg of N and 4.4 kg of P were delivered to Brasstown Creek over a 98‐day migration period. N input exceeded N export on 15 of the 98 days, but phosphorus input never exceeded P export. Eggs accounted for the majority of N and P input at 51% and 100% respectively. Redhorse N inputs peaked in the spring during a period of low N exports, suggesting that redhorse subsidies were delivered during times of elevated nutrient demand and relatively low nutrient availability. Suckers receive little management attention, and several species of redhorses are imperilled. Given our conclusion that redhorses provide a temporally critical N subsidy that is likely available to multiple consumers in freshwater food webs, this study provides compelling motivation for increased conservation of these species and their migrations. [ABSTRACT FROM AUTHOR]

Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Barriers are an effective mechanism for managing invasive species, such as sea lamprey in the Laurentian Great Lakes but are detrimental because they limit the migration of desirable, native species. Fish passage technologies that selectively pass desirable species while blocking undesirable species are needed. Optical sorting tools, combined with newly developed computer learning algorithms, could be used to identify invasive species from high-resolution imagery and potentially isolate them from an assortment of the Great Lakes fishes. Many existing barriers lack fishways, and optical sorting may require fish to be dewatered for image capture. The Archimedes screw, a device originating from 234 BCE, offers the potential to continuously lift fish and water over low-head barriers or into an optical sorting device. To test the efficacy of an Archimedes screw and fish lifting to capture and pass Great Lakes fishes, we built a field-scale prototype and installed it at the Cheboygan Dam, Michigan in the USA in 2021. The fish lift safely transported 704 fish (688 of which were suckers (Catostomidae)) in 11 days. The passage of the suckers through the fish lift increased with the water temperature and attraction flow. There were no observed injuries in the transported fish or mortalities in a subset of suckers held post-transport. [ABSTRACT FROM AUTHOR]

The first survey of caryophyllidean tapeworms parasitising catostomid and cyprinid fish in Mexico is provided, including new host and geographical records. Isoglaridacris brevicollis n. sp. is described from the Nazas sucker, Catostomus nebuliferus Garman (type host), in Durango, C. bernardini Girard in Sonora, and Moxostoma austrinum Bean (Cypriniformes: Catostomidae) in Jalisco. The new species differs from congeners mainly in the shape of the scolex, which is rounded, and by the absence of a defined neck (distinct, often long in other congeners). Pseudoglaridacris confusa found in Ictiobus meridionalis (also a member of the family Catostomidae) from Oaxaca and Veracruz represents the southern-most report of species of this Nearctic genus. Three morphotypes of the Holarctic Archigetes Leuckart, 1878 were found in two leuciscid fishes (Notropis caliensis and N. nazas) and in silverside Chirostoma sp. (Atherinidae). It is the first record of any caryophyllidean in atheriniform fish. The first record of Khawia japonensis (Yamaguti, 1934) (syn. K. iowensis Calentine et Ulmer, 1961), a parasite of common carp (Cyprinus carpio L.), in Mexico represents another evidence of its invasive potential. The caryophyllidean fauna of Mexican freshwater fish is depauperate compared to that in the United States and Canada, which seems to be related to a much lower number of species of suckers (Catostomidae) occurring in Mexico, possibly also to the lower number of fish in the population.

The Chinese sucker, Myxocyprinus asiaticus (M. asiaticus, Catostomidae, Cypriniformes), is the only living species of Catostomidae in Asia. There are more than 75 species of this family in North America. The fossil record of this group dates back to the early Eocene. As the Chinese sucker is located at the base of the Cyprinoidei phylogeny, this species is also important in clarifying the evolutionary relationships within Cyprinoidei. Here, we assembled a high-quality genome of the Chinese sucker, contig N50 (40.26 ​Mb), which is nearly ten times longer than the previous version (4.19 ​Mb). Phylogenetic analysis identified that Chinese sucker together with Cyprinidae groups are paraphyletic with respect to Cobitoidea. The specific whole genome duplication event of the Chinese sucker was estimated to have occurred ∼25.9 million years ago. Analysis of population historical changes indicated a trend of reduction for the Chinese sucker and T. tibetana. Since Dlx genes play a key role in Cypriniformes pharyngeal teeth development, we conducted a genome-wide identification of Dlx genes, and found that these genes were doubled in whole genome duplication events, followed by the loss of specific copies. Transcriptome results showed that the expression levels of these paralogous genes were similar. This genomic resource provides useful information for the protection of Chinese sucker and functional study of Dlx genes.

The relationship between June sucker (Chasmistes liorus, Jordan, 1878) and Utah sucker (Catostomus ardens, Jordan & Gilbert, 1881) has been a matter of controversy since the mid 1900s. Chasmistes liorus is endemic to Utah Lake, UT and has a subterminal mouth adapted for pelagic feeding. Catostomus ardens is widely distributed throughout the Bonneville Basin and Upper Snake River Basin and has a ventral mouth adapted for benthic feeding. Chasmistes has been recognized as a separate ancient genus. Despite being morphologically distinct, no study has successfully identified residual genetic markers that separate these species. Of these studies, several have used a subset of mitochondrial genes, but no study has analyzed the complete mitochondrial genomes (mitogenomes) of these suckers (Pisces: Catostomidae). To further explore the genetic relationships between these species, we report the complete mitogenomes of Chasmistes liorus and Catostomus ardens. DNA was sequenced using an Illumina HiSeq 2500 system and mitogenomes were assembled and annotated using Geneious v. 2021.2 and MitoAnnotator, respectively. The mitogenomes of Chasmistes liorus and Catostomus ardens are both 16,623 bp and are ∼0.072% divergent. We examine the phylogenetic relationship between Chasmistes liorus and Catostomus ardens using 33 mitogenomes, representing 16 species, from Catostomidae. Our data suggest that Chasmistes liorus is sister to Catostomus ardens. Additional samples from multiple localities and/or cohorts of these species will allow us to better resolve the complicated phylogenetic relationships between these species.

Abstract A lineage of the Mountain Sucker species complex (Pantosteus jordani) exists as a genetically and morphologically distinct taxon restricted to the Missouri River basin. This species is thought to be declining throughout its range and is assumed to be extirpated from the southern portion of its distribution. We developed a quantitative PCR‐based environmental DNA assay for P. jordani to help define and monitor its current range. The assay is both specific to P. jordani and sensitive to low amounts of DNA, with a detection limit of 10 DNA copies per reaction. In vitro experiments involved testing DNA from twenty tissue samples, collected from the Missouri River basin in Montana and Wyoming. The assay efficiently detected DNA of all P. jordani samples and did not amplify DNA of any closely related nontarget species. Additionally, 29 environmental DNA samples were taken in 19 waterbodies within P. jordani range and its presence or absence was determined prior to sampling at six of 29 sites. All sites where P. jordani was known absent produced negative results, and all sites where it was known present were confirmed with environmental DNA detections. The new assay was able to detect P. jordani at ten sites which were not previously known to contain individuals, demonstrating that this tool has the potential to rapidly expand the current understanding of this taxon's distribution.

Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The first survey of caryophyllidean tapeworms parasitising catostomid and cyprinid fish in Mexico is provided, including new host and geographical records. Isoglaridacris brevicollis n. sp. is described from the Nazas sucker, Catostomus nebuliferus Garman (type host), in Durango, C. bernardini Girard in Sonora, and Moxostoma austrinum Bean (Cypriniformes: Catostomidae) in Jalisco. The new species differs from congeners mainly in the shape of the scolex, which is rounded, and by the absence of a defined neck (distinct, often long in other congeners). Pseudoglaridacris confusa found in Ictiobus meridionalis (also a member of the family Catostomidae) from Oaxaca and Veracruz represents the southern-most report of species of this Nearctic genus. Three morphotypes of the Holarctic Archigetes Leuckart, 1878 were found in two leuciscid fishes (Notropis caliensis and N. nazas) and in silverside Chirostoma sp. (Atherinidae). It is the first record of any caryophyllidean in atheriniform fish. The first record of Khawia japonensis (Yamaguti, 1934) (syn. K. iowensis Calentine et Ulmer, 1961), a parasite of common carp (Cyprinus carpio L.), in Mexico represents another evidence of its invasive potential. The caryophyllidean fauna of Mexican freshwater fish is depauperate compared to that in the United States and Canada, which seems to be related to a much lower number of species of suckers (Catostomidae) occurring in Mexico, possibly also to the lower number of fish in the population. [Display omitted] • We present the first systematic survey of caryophyllidean tapeworms (Cestoda) in Mexico. • A new species of Isoglaridacris is described from endemic suckers (Catostomidae). • This is the first report of any caryophyllidean from atheriniform fish. • Khawia japonensis , a parasite of common carp, is reported as an invasive species in Mexico. [ABSTRACT FROM AUTHOR]

Barriers are an effective mechanism for managing invasive species, such as sea lamprey in the Laurentian Great Lakes but are detrimental because they limit the migration of desirable, native species. Fish passage technologies that selectively pass desirable species while blocking undesirable species are needed. Optical sorting tools, combined with newly developed computer learning algorithms, could be used to identify invasive species from high-resolution imagery and potentially isolate them from an assortment of the Great Lakes fishes. Many existing barriers lack fishways, and optical sorting may require fish to be dewatered for image capture. The Archimedes screw, a device originating from 234 BCE, offers the potential to continuously lift fish and water over low-head barriers or into an optical sorting device. To test the efficacy of an Archimedes screw and fish lifting to capture and pass Great Lakes fishes, we built a field-scale prototype and installed it at the Cheboygan Dam, Michigan in the USA in 2021. The fish lift safely transported 704 fish (688 of which were suckers (Catostomidae)) in 11 days. The passage of the suckers through the fish lift increased with the water temperature and attraction flow. There were no observed injuries in the transported fish or mortalities in a subset of suckers held post-transport.

Identification of introduced species can be important to understanding ecological systems and meeting conservation and management goals, but the process can be surprisingly challenging. The Klamath smallscale sucker Catostomus rimiculus seems likely to be native to the Smith River because the drainage separates two basins believed to be within the fish's native range, the Rogue and Klamath rivers. Further, C. rimiculus is broadly distributed in the Smith River, and the indigenous Dee‐ni' People of the Smith River have a unique word for sucker. Nonetheless, a historical survey of fishes that described C. rimiculus from the Rogue and Klamath rivers did not include C. rimiculus among the fishes of the Smith River. To determine whether the genetic structure of the Smith River C. rimiculus reflects expectations for a native sucker population, the authors of this study examined variation in microsatellite and mitochondrial genetic markers from the Smith River and surrounding drainages. The genetic analyses revealed a pattern consistent with extreme founder effects in Smith River C. rimiculus, as would be expected from a single introduction of six or fewer effective individuals. The sharing of a high‐frequency haplotype between the Smith River and Klamath River that is not detected in the Rogue River suggests the Klamath River as the likely source for the introduction. The findings highlight that local‐scale introductions can be easily overlooked because the newly established populations can appear to be parts of contiguous natural distributions. [ABSTRACT FROM AUTHOR]

The Eocene catostomid fish (Cypriniformes: Catostomidae) from the Allenby Formation, British Columbia, Canada, is reviewed and revised based on recently collected specimens. The fish was originally recognized as a catostomid by Cope in 1893 and described as Amyzon brevipinne. Wilson comprehensively redescribed the species in 1977 based on a large collection. More specimens collected recently brought to light the need for a systematic revision of this species, different from all known Amyzon species in having a narrow frontal bone with elongated orbital notch, shallow and slender infraorbital series, broad opercle, and short and slender rib 4. It differs from the type species Amyzon mentale in having a shorter posteroventral process of the dentary and fewer dorsal fin rays. Given the differences from all known Eocene catostomid species, Amyzon brevipinne is herein assigned to a new genus as Wilsonium brevipinne. Phylogenetically, this species is resolved as the most basal taxon of Catostomidae. The small-sized fluvial specimens of Wilsonium brevipinne represent the first recognized dwarf catostomid species in the fossil record (maximum standard length ∼ 84 mm). It is also worth noting that Wilsonium gen. nov. differs from all known catostomids in the elongated orbital notch, shallow and slender infraorbital series and non-robust rib 4. These features are seen in some loaches and gyrinchelids. [ABSTRACT FROM AUTHOR]

Between April 2011 and November 2020, 175 individuals of western creek chubsucker Erimyzon claviformis (Girard) (Cypriniformes: Catostomidae) were collected and examined for parasites from 12 sites in the Ouachita, Red, St. Francis, and White river drainages in Arkansas (n = 138 individuals for endoparasites, 22 of same individuals for gill parasites) and from 4 sites in the Red River drainage in Oklahoma (n = 37 individuals for endoparasites, 14 of same individuals for gill parasites). Ninety-nine (57%) were infected with at least 1 parasite, including 2 (6%) of 36 with Piscinoodinium limneticum, 8 (22%) of 36 with 3 different Myxobolus spp., 4 (11%) of 36 with Octomacrum lanceatum, 40 (23%) of 175 with Plagioporus sinitsini, 30 (17%) of 175 with Lissorchis amniculensis, 38 (21%) of 175 with Calientiella etnieri, 3 (2%) of 175 with Isoglaridacris cf. agminis, 10 (6%) of 175 with larval Spiroxys sp., and 1 (0.6%) of 175 with a Neoechinorhynchus sp.; 31 individuals harbored multiple infections. We document several new host and distributional records. Moreover, this report represents only the second published report of the caryophyllid tapeworm C. etnieri since its description more than 46 yr ago. [ABSTRACT FROM AUTHOR]

The relationship between June sucker (Chasmistes liorus, Jordan, 1878) and Utah sucker (Catostomus ardens, Jordan & Gilbert, 1881) has been a matter of controversy since the mid 1900s. Chasmistes liorus is endemic to Utah Lake, UT and has a subterminal mouth adapted for pelagic feeding. Catostomus ardens is widely distributed throughout the Bonneville Basin and Upper Snake River Basin and has a ventral mouth adapted for benthic feeding. Chasmistes has been recognized as a separate ancient genus. Despite being morphologically distinct, no study has successfully identified residual genetic markers that separate these species. Of these studies, several have used a subset of mitochondrial genes, but no study has analyzed the complete mitochondrial genomes (mitogenomes) of these suckers (Pisces: Catostomidae). To further explore the genetic relationships between these species, we report the complete mitogenomes of Chasmistes liorus and Catostomus ardens. DNA was sequenced using an Illumina HiSeq 2500 system and mitogenomes were assembled and annotated using Geneious v. 2021.2 and MitoAnnotator, respectively. The mitogenomes of Chasmistes liorus and Catostomus ardens are both 16,623 bp and are ∼0.072% divergent. We examine the phylogenetic relationship between Chasmistes liorus and Catostomus ardens using 33 mitogenomes, representing 16 species, from Catostomidae. Our data suggest that Chasmistes liorus is sister to Catostomus ardens. Additional samples from multiple localities and/or cohorts of these species will allow us to better resolve the complicated phylogenetic relationships between these species. [ABSTRACT FROM AUTHOR]

Reservoirs and associated river fragments are novel ecosystems not experienced by fishes in their evolutionary history, yet they are now commonplace across the globe. Understanding how fishes use these novel habitats is vital to conservation efforts in contemporary riverscapes.Movement patterns of the endangered razorback sucker (Xyrauchen texanus) synthesized from tagging efforts in the upper Colorado River basin, USA, illustrate the applications of tagging technology and data sharing by multiple agencies to better understand the spatial ecology of large river fishes.Tagging studies between 2014 and 2018 in Lake Powell and its two main tributary rivers, the Colorado (unfragmented) and San Juan (waterfall‐fragmented), were used to quantify movement of razorback sucker within this river–reservoir habitat complex. In addition, facilitated translocations of fish upstream of a waterfall barrier in the San Juan River were assessed in 2016–2017.Extensive movement of fish occurred within and across river and reservoir habitats. Of 722 fish captured in the Colorado River arm of Lake Powell, 36% of re‐encounters occurred upstream in the Colorado or Green rivers, or fish dispersed through the reservoir and were detected in the San Juan River arm. Fourteen fish moved more than 600 km. In the San Juan arm of the reservoir, 29% and 20% of fish in 2017 and 2018, respectively, had moved ~30–40 km upstream below the waterfall in the San Juan River within a year. In 2016–2017, 303 fish were translocated upstream of the waterfall into the San Juan River, but 80% were re‐encountered downstream of the waterfall within a year.Long‐distance movements by razorback sucker were common within and among rivers and reservoirs illustrating how large river fish, in general, might maintain population connectivity in highly altered ecosystems. [ABSTRACT FROM AUTHOR]

In Oregon and Washington coastal streams, there are relatively diverse faunas on the Olympic Peninsula of Washington (Chehalis fauna), in the lower Columbia River, and on the south-central Oregon coast (Tyee fauna). Adjacent to the Tyee fauna are groups of streams with depauperate faunas (0–2 primary freshwater fishes). To the north, from the Nehalem River to the Alsea River, streams have 0–1 species (Oregon Coast Range Isolates), and to the south, from the Rogue River to the Klamath River, streams have 0–2 species (Klamath Isolates). Throughout the entire area there was no relationship between drainage area and freshwater fish diversity. Multiple processes are responsible for these patterns. Two endemic genera, Oregonichthys and Novumbra, originated by the Miocene (23–5.3 Mya) and current distributions are largely bordered by the continental flood-basalt flows of the Columbia River Basalt Group (CRBG). It is hypothesized that both genera were isolated by early Miocene Grande Ronde basalt flows, Oregonichthys to the south of the flows in an ancestral Umpqua River, and Novumbra to the north of the flows in an ancestral Chehalis River. The depauperate streams of the Oregon Coast Range Isolates are hypothesized to be the result of bisection of ancient coastal streams by uplift of the Oregon Coast Range and subsequent extinction of the ancestral fauna on west-slope streams either from changing habitats or stochastic events in smaller streams. The Klamath Isolate streams drain the southern Oregon Coast Range and Klamath Mountains, an ancient region otherwise known for its faunal and floral diversity. It is hypothesized that these streams, some of which are relatively large and would be expected to have relatively diverse faunas, have been isolated from diverse primary freshwater fish faunas to the north (Columbia) and south (Sacramento), and most taxa have simply never had access to these streams. [ABSTRACT FROM AUTHOR]

Flood discharge containing excessive suspended sediments (SS) can result in total dissolved gas (TDG) supersaturation downstream of dams. It has been confirmed that high TDG levels and excessive SS cause serious threats to fish survival. To explore the effects of TDG supersaturation on the hatchability of Chinese sucker (Myxocyprinus asiaticus Bleeker) eggs, eggs were exposed to 100%, 125%, 130% and 135% TDG supersaturated water. The results showed that the hatching rates were 78.25%, 75.35%, 71.30% and 67.50% at the 100%, 125%, 130% and 135% TDG respectively. The hatching rate decreased with increasing TDG levels. Furthermore, acute lethality experiments were carried out to investigate the interaction of TDG supersaturation and SS on Chinese sucker. Half‐year‐old juveniles were exposed to TDG supersaturated water with SS concentrations of 0, 200, 600 and 1,000 mg/L, and the TDG levels were 125%, 130%, 135% and 140% respectively. The fish exhibited abnormal behaviours and signs of gas bubble disease. Mortality increased with increasing TDG levels and SS concentrations. The Chinese suckers only survived for 2.5 hr at 140% TDG and 1,000 mg/L SS. Moreover, an increase in SS in TDG supersaturated water could cause a decrease in the median lethal time (LT50). When the TDG level reached 140%, the LT50 declines significantly at 600 and 1,000 mg/L SS. The interaction of TDG supersaturation and SS was significant at LT50 (F = 22.81, df = 9, p < 0.001). The results indicate that the combined effect of TDG and SS could be great on Chinese sucker. [ABSTRACT FROM AUTHOR]

The June Sucker Chasmistes liorus mictus is a large-bodied catostomid endemic to Utah Lake, Utah. It is a federally listed endangered species, and one component to its recovery is a stocking program with a target of releasing 2.8 million fish averaging 200 mm long. Because size is implicated as a factor in poststocking survival of western native fishes, particularly in the presence of nonnative fishes, over a 4-year period a combination of telemetry and remote sensing was used to demonstrate size-specific poststocking survival of June Sucker in Utah Lake. A total of 88 June Sucker were released with acoustic tags to estimate short-term survival, and remote PIT scanners were deployed to examine longterm survival. Survival of telemetry fish varied from 0.0 to 0.83, with larger fish exhibiting the greatest survival in the final year. Size-specific survival was most evident in the analysis of PIT scanning data in which survival ranged from 2% for fish shorter than 200 mm to 90% for fish stocked at 300 mm. The causes of mortality are unknown, but likely culprits are nonnative fish and piscivorous birds. Both are well documented preying on June Sucker and similar species. Controlling predation may be impractical, but releasing fewer numbers of larger fish presumably will increase or maintain the population and be more cost effective than the current strategy. Overall, conservation and recovery of June Sucker will be a challenging endeavor going forward. [ABSTRACT FROM AUTHOR]

This is a reporting on the occurrence of little known species of earthworm Megascolex lawsoni (Bourne, 1886), of the Family Megascolecidae for the first time from the political boundary of the State of Kerala. Specimens were collected from 12 locations within Wayanad District. So far, they have been reported from neighbouring states of Tamil Nadu and Karnataka. Its current geographical distribution and information on certain aspects of its biology are provided. [ABSTRACT FROM AUTHOR]

From 2015 to 2016, the hepatopancreatic lesion syndrome had a higher mortality rate, which caused great economic losses to farmer. In order to study the high-efficiency disease-preventing crab pond intercropping mode, an experiment was successfully conducted to intercrop Chinese sucker (Myxocyprinus asiaticus) in a crab pond in 2017. We optimized the traditional stocking mode, and mainly cultured river crabs when intercropping Chinese suckers. Meanwhile, the cultivation environment was strengthened, and the test pond was not affected by disease throughout the year. The results showed that the production benefits were river crab 115 620 yuan/hm², Chinese sucker 44 280 yuan/hm², and silver carp and bighead carp) 5 418 yuan/hm², with a total output of 165 318 yuan/hm², and the output-input ratio was 11.72. The Chinese sucker-intercropping river crab culture mode promoted the improvement of pond culture environment, effectively controlled the occurrence of hepatopancreatic lesion syndrome, and significantly improved the economic benefits of crab pond culture. [ABSTRACT FROM AUTHOR]

Chinese sucker (Myxocyprinus asiatius) is a national secondary protection animal in China, a well as unique economic fish in China having extremely important scientific research value and edible value. With the aggravation of water pollution and the massive construction of water conservancy and hydropower projects, the natural spawning ground of Chinese sucker has been seriously damaged. The current number of wild resources has decreased sharply, and the decreasing trend is continuing. This paper summarized the current resource status and monitoring and assessment methods of Chinese sucker, and put forward the research prospect, so as to provide theoretical reference and technical support for resource protection and development and utilization of Chinese sucker in China. [ABSTRACT FROM AUTHOR]

The Lost River Sucker Deltistes luxatus and Shortnose Sucker Chasmistes brevirostris are two narrowly endemic fish species in the upper Klamath Basin of southern Oregon and northern California. Both species have been federally listed as endangered pursuant to the U.S. Endangered Species Act since 1988 because of dramatic declines in abundance and distribution. In Upper Klamath Lake, Oregon, both species have only recruited a single cohort to the adult populations since that time. Most individuals in this population are at or older than the expected life span of the species. Consequently, the U.S. Fish and Wildlife Service and the Klamath Tribes have initiated assisted rearing efforts to stabilize the population. However, it is unclear how quickly these populations might become extirpated and how assisted rearing might alter population trajectories. We modeled the potential for extinction and recovery of the populations of endangered Lost River Sucker and Shortnose Sucker in Upper Klamath Lake. We simulated population trajectories over the next 50 y with a stochastic population viability assessment approach. Projections indicate that if population trajectories do not change, the Shortnose Sucker population may decline by 78% to number < 5,000 in 10 y and become completely extirpated within the next 30 (18.6% probability) to 40 y (99% probability). The two Lost River Sucker populations have a greater likelihood to remain extant after 50 y, with only 1% probability of extinction given our scenarios and assumptions, but the populations are likely to number fewer than 1,000 individuals. Our results also suggest that rearing of Klamath Lake sucker species in a controlled environment for augmenting the natural population will be effective in reducing extirpation probabilities over the next 50 y if survival to recruitment can be achieved, but a long-term effort of at least 40 y will be required. The necessity of long-term augmentation to ensure population persistence in the absence of natural recruitment underscores the urgent need to determine and address the causes of recruitment failure in the wild. [ABSTRACT FROM AUTHOR]

Catostomidae (“suckers”) is a diverse (76 species) and broadly distributed family of Holarctic freshwater fishes with a rich fossil record and a considerable number (∼35%) of threatened and imperiled species. We integrate DNA sequences (three mitochondrial genes, three nuclear genes), morphological data, and fossil information to infer sucker phylogenetic relationships and divergence times using Bayesian “total-evidence” methods, and then test hypotheses about the temporal diversification of the group. Our analyses resolved many nodes within subfamilies and clarified Catostominae relationships to be of the form ((Thoburniini, Moxostomatini), (Erimyzonini, Catostomini)). Patterns of subfamily relationships were incongruent, but mainly supported two placements of the Myxocyprininae; distinguishing these using Bayes factors lent strongest support to a model with Myxocyprininae sister to all remaining sucker lineages. We improved our Bayesian total-evidence dating analysis by excluding problematic characters, using a clock-partitioning scheme identified by Bayesian model selection, and employing a fossilized birth-death tree prior accommodating morphological data and fossils. The resulting chronogram showed that suckers evolved since the Late Cretaceous–Eocene, and that the Catostomini and Moxostomatini clades have accumulated species diversity since the early to mid-Miocene. These results agree with the fossil record and confirm previous hypotheses about dates for the origins of Catostomide and catostomine diversification, but reject previous molecular hypotheses about the timing of divergence of ictiobines, and between Asian–North American lineages. Overall, our findings from a synthesis of multiple data types enhance understanding of the phylogenetic relationships, taxonomic classification, and temporal diversification of suckers, while also highlighting practical methods for improving Bayesian divergence dating models by coupling phylogenetic informativeness profiling with relaxed-clock partitioning.

A new species of monogenean, Dactylogyrus pisolabrae n. sp., was found parasitizing the gills of the Pealip Redhorse, Moxostoma pisolabrum, from Oklahoma. Dactylogyrus pisolabrae is morphologically similar to Dactylogyrus apos, Dactylogyrus atripinnei, Dactylogyrus duquesnei, and Dactylogyrus niger, all parasitizing other species of suckers, by possessing a robust, sickleshaped male copulatory organ, but differs from these and all other species of North American Dactylogyrus by possessing 2 unique wing-like projections opposite each other on the proximal portion of the accessory piece. Dactylogyrus pisolabrae represents the first monogenean reported from the Pealip Redhorse. [ABSTRACT FROM AUTHOR]

Abstract. Facultative spawning in lakes is an uncommon and notable behavior among catostomids and other fish species that typically spawn in streams. I describe what may be the first documented case of lake-spawning behavior by mountain suckers (Catostomus platyrhynchus). [ABSTRACT FROM AUTHOR]

Populations of Black Buffalo Ictiobus niger , a broadly-distributed catostomid species native to the Mississippi River basin, are in decline, similar to many other catostomids. Artificial propagation and culture are frequently a part of native species recovery plans, and developing formulated diets is a critical component of these plans. However, studies establishing protein requirements for catostomids are limited, particularly for larger juvenile to sub-adult sizes, even though catostomids are commonly reared to these sizes. Therefore, we conducted a 10-week growth study to evaluate optimal protein levels in juvenile (age-1) Black Buffalo (mean ± SE: total length = 218.7 ± 0.8 mm, weight = 148.5 ± 1.6 g). Five practical diets were formulated to contain 30, 34, 38, 41, and 45% crude protein with each diet fed to four replicate tanks (400-L) containing 10 fish each. Fish fed a diet containing 41% crude protein had greater biomass gain (total weight gain for all fish in the tank) when compared to other diets. Individual weight gain (percent increase) was greater in fish fed diets containing 41% and 45% protein compared to lower protein diets. Results from this study suggest a diet with 41% crude protein would produce optimal growth for juvenile (age-1) Black Buffalo. [ABSTRACT FROM AUTHOR]

Abstract: The Black Buffalo Ictiobus niger is a deep‐bodied, riverine species that has experienced population declines similar to many other catostomids. Captive propagation is an important component of conservation for declining species, although there is little known about induced spawning techniques for catostomids. Developing culture techniques for Black Buffalo, including tank acclimation and induced spawning, are potentially beneficial for conserving other catostomids as well. Therefore, we examined tank acclimation and induced‐spawning methods in three separate spawns over 2 years. Acclimation was aided by cool temperatures (~15°C), low salinity (3.0‰), and light‐reducing covers for 2.5 weeks after which temperature was increased from 15°C to 23°C by 1°C/d over 8 d. Females (n = 23; TL = 641 ± 12 mm [mean ± SE], weight = 4,773 ± 299 g) were injected with the gonadotropin‐releasing hormone analogue (GnRHa), and 7 of 23 ovulated (30.4%) with a mean fertilization percentage of 41.5% (SE, 7.1%). Large fish and fungal growth on incubating embryos provided logistical challenges, further indicating the importance of minimizing stress during tank‐holding procedures. This study outlines effective tank acclimation procedures and demonstrates that Black Buffalo can be induced to spawn with GnRHa. [ABSTRACT FROM AUTHOR]

Catostomidae ("suckers") is a diverse (76 species) and broadly distributed family of Holarctic freshwater fishes with a rich fossil record and a considerable number (~35%) of threatened and imperiled species. We integrate DNA sequences (three mitochondrial genes, three nuclear genes), morphological data, and fossil information to infer sucker phylogenetic relationships and divergence times using Bayesian "total-evidence" methods, and then test hypotheses about the temporal diversification of the group. Our analyses resolved many nodes within subfamilies and clarified Catostominae relationships to be of the form ((Thoburniini, Moxostomatini), (Erimyzonini, Catostomini)). Patterns of subfamily relationships were incongruent, but mainly supported two placements of the Myxocyprininae; distinguishing these using Bayes factors lent strongest support to a model with Myxocyprininae sister to all remaining sucker lineages. We improved our Bayesian total-evidence dating analysis by excluding problematic characters, using a clockpartitioning scheme identified by Bayesian model selection, and employing a fossilized birth-death tree prior accommodating morphological data and fossils. The resulting chronogram showed that suckers evolved since the Late Cretaceous- Eocene, and that the Catostomini and Moxostomatini clades have accumulated species diversity since the early to mid-Miocene. These results agree with the fossil record and confirm previous hypotheses about dates for the origins of Catostomide and catostomine diversification, but reject previous molecular hypotheses about the timing of divergence of ictiobines, and between Asian-North American lineages. Overall, our findings from a synthesis of multiple data types enhance understanding of the phylogenetic relationships, taxonomic classification, and temporal diversification of suckers, while also highlighting practical methods for improving Bayesian divergence dating models by coupling phylogenetic informativeness profiling with relaxed-clock partitioning. [ABSTRACT FROM AUTHOR]

Two catostomid fishes, Carpiodes cyprinus (Quillback) and Moxostoma collapsum (Notchlip Redhorse), were recently discovered in the New River watershed (Ohio River basin) in Virginia. The New River fish fauna is naturally depauperate relative to surrounding watersheds, and it has been altered substantially due to non-indigenous species introductions. Notchlip Redhorse and Quillback are established in Claytor Lake and are dispersing into novel reaches of the mainstem New River. We suspect that these species became established following bait-bucket introductions or incidentally during game-fish stockings. Public education, policy changes, and stricter hatchery procedures are needed to minimize such occurrences of non-indigenous species introductions. [ABSTRACT FROM AUTHOR]

A taxonomic study of monozoic cestodes of the genus Glaridacris Cooper, 1920 (Cestoda: Caryophyllidea), parasites of catostomid fishes in North America, confirmed artificial character of the genus which is split to 2 different, morphologically distinct, and not closely related genera. Glaridacris is newly circumscribed to include only 3 species, Glaridacris catostomi Cooper, 1920 (type species), Glaridacris terebrans ( Linton, 1893 ), and Glaridacris vogei Mackiewicz, 1976 , which are characterized by an elongate body, a cuneiloculate or wedge-shaped scolex with 6 shallow loculi, male and female gonopores at a distance from each other, follicular ovary, and circum-medullary vitelline follicles (lateral and median). A new genus, Pseudoglaridacris n. gen., is proposed to accommodate 3 species characterized by a shorter body, a bothrioloculodiscate scolex with a pair of deeper median bothria and 2 shallower loculi, male and female gonopores close together, non-follicular ovary, and with only lateral vitelline follicles. The species are: Pseudoglaridacris laruei ( Lamont, 1921 ) n. comb. (type species), Pseudoglaridacris confusa (Hunter, 1929) n. comb., and Pseudoglaridacris oligorchis ( Haderlie, 1953 ) n. comb. An annotated list of all species of both genera, with data on their hosts and distribution and keys to their identification, is provided. [ABSTRACT FROM AUTHOR]

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Many fish species exhibit diverse life history strategies that help maintain population viability. An understanding of the relationships among these strategies is crucial for prioritising conservation actions. The Warner sucker, endemic to the Warner Lakes Basin in southern Oregon, USA, is one example of a taxon where a lack of information regarding relationships among life history strategies has hampered conservation efforts. Warner suckers have two distinct life history types: stream-type fish that have a fluvial life history and lake-type fish that have an adfluvial life history. There are advantages and disadvantages associated with each life history, and presently the relationship between life history types is not well understood. Our objectives were to determine the amount of genetic variation within and among tributary populations of Warner suckers and to determine the origins of suckers collected in the Warner Lakes. We collected individuals from four tributary populations, a refugial population, and Hart and Crump lakes and genotyped them at 16 microsatellite loci. Estimates of genetic variation among populations suggested low levels of gene flow ( FST = 0.153) and genetic variation among populations seemed to be influenced by population and habitat characteristics. Nearly all of the individuals collected in Hart and Crump lakes originated in a single tributary, Deep Creek, which likely reflects reduced habitat connectivity between most other tributaries and the Warner Lakes. Data presented in this study are useful for evaluating the status of Warner sucker populations and for prioritising conservation actions such as the removal and modification of barriers. [ABSTRACT FROM AUTHOR]

Remoras of the ray-finned fish family Echeneidae have the remarkable ability to attach to diverse marine animals using a highly modified dorsal fin that forms an adhesive disc, which enables hitchhiking on fast-swimming hosts despite high magnitudes of fluid shear. We present the design of a biologically analogous, multimaterial biomimetic remora disc based on detailed morphological and kinematic investigations of the slender sharksucker (Echeneis naucrates). We used multimaterial three-dimensional printing techniques to fabricate the main disc structure whose stiffness spans three orders of magnitude. To incorporate structures that mimic the functionality of the remora lamellae, we fabricated carbon fiber spinules (270 μm base diameter) using laser machining techniques and attached them to soft actuator-controlled lamellae. Our biomimetic prototype can attach to different surfaces and generate considerable pull-off force--up to 340 times the weight of the disc prototype. The rigid spinules and soft material overlaying the lamellae engage with the surface when rotated, just like the discs of live remoras. The biomimetic kinematics result in significantly enhanced frictional forces across the disc on substrates of different roughness. Using our prototype, we have designed an underwater robot capable of strong adhesion and hitchhiking on a variety of surfaces (including smooth, rough, and compliant surfaces, as well as shark skin). Our results demonstrate that there is promise for the development of high-performance bioinspired robotic systems that may be used in a number of applications based on an understanding of the adhesive mechanisms used by remoras. [ABSTRACT FROM AUTHOR]

Erromyzon damingshanensis, a new sucker loach is described from the Pearl River drainage in Guangxi, China. The new species Erromyzon damingshanensis is distinguished from the other species of the genus in having a crescentic median lobe of the rostral fold, rostral barbels shorter than rostral fold; postlabial groove broadly interrupted medially, seven branched dorsal fin rays, 16 branched pectoral fin rays, lateral line scales 88-95, caudal peduncle depth larger than its length; body with 12 irregular bars on flank, interrupted on dorsum. [ABSTRACT FROM AUTHOR]

A large collection of caryophyllaeid tapeworms from catostomid fishes in eastern Texas, U.S.A. was utilized to evaluate the reliability of key morphological features that putatively distinguish between Glaridacris confusus and Glaridacris laruei. The number of testes, anterior extent of the testicular and vitelline fields, shape of the postovarian vitelline follicles, spatial relationship between the postovarian vitelline follicles and the ovary, postgonopore distance, and dimensions of the testes were all examined to determine if they correlated, as suggested in published dichotomous keys. No character was unambiguously associated with the overall morphotype of either species, and features supposedly diagnostic of one species were associated with features supposedly diagnostic of the other. The high variability among these character associations observed in the present investigation, combined with the variability reported by past investigations, suggests that new collections will be needed to clarify the species-level diversity in Glaridacris. [ABSTRACT FROM AUTHOR]

Serial impoundment of major rivers leads to alterations of natural flow dynamics and disrupts longitudinal connectivity. Catostomid fishes (suckers, family Catostomidae) are typically found in riverine or backwater habitats yet are able to persist in impounded river systems. To the detriment of conservation, there is limited information about distribution of catostomid fishes in impounded rivers. We examined the longitudinal distribution of catostomid fishes over 23 reservoirs of the Tennessee River reservoir cascade, encompassing approximately 1600 km. Our goal was to develop a basin-scale perspective to guide conservation efforts. Catostomid species composition and assemblage structure changed longitudinally along the reservoir cascade. Catostomid species biodiversity was greatest in reservoirs lower in the cascade. Assemblage composition shifted from dominance by spotted sucker Minytrema melanops and buffalos Ictiobus spp. in the lower reservoirs to carpsuckers Carpiodes spp. midway through the cascade and redhorses Moxostoma spp. in the upper reservoirs. Most species did not extend the length of the cascade, and some species were rare, found in low numbers and in few reservoirs. The observed gradients in catostomid assemblages suggest the need for basin-scale conservation measures focusing on three broad areas: (1) conservation and management of the up-lake riverine reaches of the lower reservoirs, (2) maintenance of the access to quality habitat in tributaries to the upper reservoirs and (3) reintroductions into currently unoccupied habitat within species' historic distributions. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Gene choice, base compositional heterogeneity and rate heterogeneity are known to influence phylogenetic reconstruction but are often overlooked. Here, we investigate the impact of these factors in reconstructing the phylogenetic relationships and divergence times of cypriniform fishes. We compile a multilocus data set of newly sequenced and previously published nuclear protein-coding genes from species from all major lineages of Cypriniformes. We collect data on the oldest known cypriniform fossils and gather body size information. We demonstrate that body size correlates with rates of molecular evolution and contributes to rate heterogeneity not only in Cypriniformes but also in a number of other fish lineages. We find that miniaturized cypriniforms show exceptionally high rates of molecular evolution that may lead to improper phylogenetic placement of these taxa due to issues associated with branch attraction. We identify and correct for base compositional heterogeneity and find that this has a marked impact on topology and a corresponding impact on the estimation of divergence times within Cypriniformes. Using gene sequences, fossil calibrations and two different methods, we show strong evidence that Catostomidae is sister to all other cypriniform families and the major clades of cypriniform fishes diverged long before their fossil record indicates. [ABSTRACT FROM AUTHOR]

Evaluating the precision of age estimates generated by different readers and different calcified structures is an important part of generating reliable estimations of growth, recruitment, and mortality for fish populations. Understanding the potential loss of precision associated with using structures harvested without sacrificing individuals, such as scales or fin rays, is particularly important when working with imperiled species, such as Cycleptus elongatus (Blue Sucker). We collected otoliths (lapilli), scales, and the first fin rays of the dorsal, anal, pelvic, and pectoral fins of 9 Blue Suckers. We generated age estimates from each structure by both experienced ( n = 5) and novice ( n = 4) readers. We found that, independent of the structure used to generate the age estimates, the mean coefficient of variation (CV) of experienced readers was approximately 29% lower than that of novice readers. Further, the mean CV of age estimates generated from pectoral-fin rays, pelvic-fin rays, and scales were statistically indistinguishable and less than those of dorsal-fin rays, anal-fin rays, and otoliths. Anal-, dorsal-, and pelvic-fin rays and scales underestimated age compared to otoliths, but age estimates from pectoral-fin rays were comparable to those from otoliths. Skill level, structure, and fish total-length influenced reader precision between subsequent reads of the same aging structure from a particular fish. Using structures that can be harvested non-lethally to estimate the age of Blue Sucker can provide reliable and reproducible results, similar to those that would be expected from using otoliths. Therefore, we recommend the use of pectoral-fin rays as a non-lethal method to obtain age estimates for Blue Suckers. [ABSTRACT FROM AUTHOR]

In Lake Tanganyika, several lineages of cichlids have diversified into 200 species. Tribe Tropheini contains the greatest richness of herbivorous species that are classified into four ecomorphs: grazers, browsers, suckers, and pickers. All of these ecomorphs coexist on littoral rocky shores. To reveal the differences among species within ecomorphs, we analysed fish shape and functional morphology related to feeding habits, using geometric morphometrics, and measured intestine length. Furthermore, we tested the relationship between genetic and morphological distances. As a result, diversities of functional morphology among ecomorphs, and among species within ecomorphs, were revealed. In grazers, morphological diversity was greatest in jaws and the opening direction of mouth, suggesting that these species have adapted to feed on various substrata. In browsers, intestine length varied among species, indicating that this ecomorph consists of species with various specializations in herbivory. Morphological divergence was found only in the mandible and occlusal facet in grazers. No clear relation was found between morphological and phylogenetic distances in browsers, which are a polyphyletic group, indicating that their traits were acquired by convergence in multiple lineages. Our data suggest that the observed morphological variation among species enable sympatric species to separate their feeding niches. [ABSTRACT FROM AUTHOR]