Fish Collection Research Articles

Population structure of exotic fish tilapia (Oreochromis mossambicus P. 1852) in Vallabhsagar reservoir - a large aquatic ecosystem on western ghats of India

The present study was conducted to find out the population structure of the studied fish tilapia which provides the information on the exploitation pattern, existing growth and sustainability of the fish in the surrounding aquatic environment. The random fish scale samples (505 numbers) were collected at monthly basis during the month of November 2021 to April 2022 from different commercial fish collection center at Vallabhsagar reservoir, Gujarat for the proposed study of exotic fish tilapia (Oreochromis mossambicus). The findings of the study shows that fishes varied from 1+ to 5+ age classes and in which 4+ (29%) age group was dominated which followed by 2+ (26%), 3+ (25%), 1+ (12%) and 5+ (9%) of the total population. Moreover, bell shaped age pyramid of tilapia was observed by the balanced population growth due to static aquatic environment in Vallabhsagar reservoir, Gujarat. The increasing length and weight indicated that aquatic environment was favorable for Oreochromis mossambicus in study area may be due to abundance of energy rich food. This rare study in this particular area have been found very useful to evaluate the status of populations, scientific management of fisheries and stock assessment.

Возраст и рост обыкновенного судака Sander lucioperca в разнотипных водоемах юга Западной Сибири

The age and growth of fish are the most important characteristics underlying the assessment of the state of fish stocks and the forecasting of future catches. The pike-perch Sander lucioperca (Linnaeus, 1758) is an alien fish species in Western Siberia. It was first introduced into the Ob basin in 1956. The introduction of this species into the Novosibirsk reservoir was carried out in 1959-1964, and into Lake Chany in 1964-1966. Currently, pike-perch is spread throughout the Ob basin and is an important fishery target. This study summarizes long-term data from the Novosibirsk branch of Russian Federal Research Institute of Fisheries and Oceanography ("VNIRO") about the growth of different-aged individuals of the pike-perch, collected during monitoring of aquatic biological resources in the Novosibirsk reservoir (54°20' N, 81°57'E) and Lake Chany (54°55'N, 77°31'E) over the last 10 years (2013-2022). These water bodies are of different types: the Novosibirsk reservoir was formed on the Ob River, the maximum depth reaches 25 m, the average depth is 8 m. The area of the reservoir is 1.07 thousand km^. Lake Chany is located in the Ob-Irtysh interfluve, drainless, filled due to the runoff of the Kargat and Chulym rivers, atmospheric precipitation and groundwater. The maximum depth is up to 8 m, average depth is 2 m. The area of the lake fluctuates greatly from year to year depending on the water level, in the long-term aspect it has tends to decrease, currently amounting to about 2 thousand km. The lake water has increased mineralization in most of the reaches. Fish collection for analysis of size characteristics is carried out annually from commercial catches. The total volume of material for this study was 2953 individuals from Lake Chany and 1102 individuals from the Novosibirsk reservoir. As a result of this work, it was found that in commercial catches in different types of water bodies in the south of Western Siberia, pike-perch has been known at the age of up to 14+ years over the last 10 years. In Lake Chany, there were mostly individuals of age groups 2+-4+, and in the Novosibirsk Reservoir - 3+-6+ (See Fig. 1). The pike-perch size of the same age from commercial catches varies greatly from one year to the next in Lake Chany, and in the Novosibirsk reservoir (See Fig. 2). It confirms the data on significant variability in growth rates of this species and indicating the need for a cautious approach to comparing the length and weight of pike perch in different observation periods. On average, over the last decade, pike-perch in Lake Chany is characterized by a slightly shorter standard length and greater weight than in the Novosibirsk Reservoir, however, the differences reach statistical significance (p < 0.001) only when comparing fish aged 2+ by standard length (See Fig. 3). The analysis of the relationship between the growth rate of pike-perch and environmental temperature showed that the absolute increase per year of standard length and weight of younger age groups fish in the Novosibirsk Reservoir has a statistically significant positive correlation with the temperature in April (r = 0.6110.775), and in Lake Chany - in May (r = 0.633-0.737) (See Tables 1, 2). Considering that the average April temperature in the area of the Novosibirsk reservoir is 1.9°C higher than in the area of Lake Chany, probably, in the latter, juvenile pike-perch begins to actively feeding a little later. It may explain the smaller sizes of pike-perch of younger age groups in Lake Chany compared to the Novosibirsk reservoir. The article contains 4 Figures, 2 Tables and 28 References. The authors express their gratitude to all colleagues - employees of the Novosibirsk Branch of "VNIRO", who over in different years took part in collecting the material. The Authors declare no conflict of interest.

Comparison of Ectoparasites infestation for fresh and saltwater Fishes from Euphrates, and Razzaza Lake, Iraq

Parasitic infestations represent one of the main challenges to fresh water and marine fish all areas of the world. The infections are commonly found on the skin and gills of fish and can cause dangerous problems, as mortality, in heavily parasitized infections. This study was conducted to detect of ectoparasite types in Fishes, 200 of Coptodon zillii from Euphrates and 120 Cyprinus carpio from Razzaza Lake, were used for this study in aquatic environment. The specimens were purchased at 2022 in different periods from market and selected. The collection of fish using gill nets. The collected of fish samples was carried out in lab and used macroscopic inspection, gross viscera, microscopic exam-wet mount of fins, skin, gills and eyes. The results of the both infected fishes revealed the presence of several clinical signs. The prevalence was 65.6%, in Coptodon zillii was 30% and Cyprinus carpio was 100%. Indeed, we observed the appearance of necrotic areas, ulcerations and hemorrhage on the gills. On others body parts, we found Protozoa and Monogeneans parasites. The identification of ectoparasite were obtained in fins, skin, and gills and no infection in eyes. There are 4 types of ectoparasites were infect to Coptodon zillii, that is Trichodina sp., Ichthyophthirius multifiliis sp., Dactylogyrus sp., and Gyrodactylus sp. While, Cyprinus carpio that is I. multifiliis and Gyrodactylus sp. Significantly of results at P≤0.05 of fish type with weight and long but not significant for genders in both types. In future studies should be focusing on modern tools to identification of parasites species in different environments.

The fish collection of Jos Mariano da Conceio Veloso (17421811) and the beginning of ichthyological research in Brazil, with a taxonomic description of the extant specimens.

Two Portuguese institutions, the Museu Maynense da Academia das Cincias de Lisboa (ACL), and the Museu da Cincia da Universidade de Coimbra (MCUC), house a collection of 85 dried fish specimens prepared in what can be called a fish-herbaria following a process similar to that developed by the Dutch naturalist Johan Frederic Gronovius (16901762). These specimens date back to the late eighteenth century and represent Brazilian taxa. Previous authors assumed that they were part of the collections amassed by the Brazilian-Portuguese naturalist Alexandre Rodrigues Ferreira (17561815) during his philosophical voyage to the Amazon. Here we present a review of these specimens, suggesting that they belonged to Friar Jos Mariano da Conceio Veloso (17421811) and describe the history of dispersal of these collections up the present day. A total of 58 species in 50 genera, 32 families and 19 orders are represented in the collection. Only 8.6% of these specimens represent freshwater species, while 91.4% are marine or brackish water species. The present known distribution of these taxa is focused on southwestern Brazil, which agrees with the area where Veloso collected natural history specimens. A good percentage of the species were undescribed at the time Veloso collected them, and had they been published by him, would have had priority over species described decades later by famous eighteenth and nineteenth century ichthyologists. We also present a brief discussion on the challenges and opportunities of studying historical natural history specimens, with special focus on those amassed during the late eighteenth and early nineteenth century by Brazilian-Portuguese naturalists.

Tissue Distribution and Metabolization of Ciguatoxins in an Herbivorous Fish following Experimental Dietary Exposure to Gambierdiscus polynesiensis.

Ciguatoxins (CTXs), potent neurotoxins produced by dinoflagellates of the genera Gambierdiscus and Fukuyoa, accumulate in commonly consumed fish species, causing human ciguatera poisoning. Field collections of Pacific reef fish reveal that consumed CTXs undergo oxidative biotransformations, resulting in numerous, often toxified analogs. Following our study showing rapid CTX accumulation in flesh of an herbivorous fish, we used the same laboratory model to examine the tissue distribution and metabolization of Pacific CTXs following long-term dietary exposure. Naso brevirostris consumed cells of Gambierdiscus polynesiensis in a gel food matrix over 16 weeks at a constant dose rate of 0.36 ng CTX3C equiv g-1 fish d-1. CTX toxicity determination of fish tissues showed CTX activity in all tissues of exposed fish (eight tissues plus the carcass), with the highest concentrations in the spleen. Muscle tissue retained the largest proportion of CTXs, with 44% of the total tissue burden. Moreover, relative to our previous study, we found that larger fish with slower growth rates assimilated a higher proportion of ingested toxin in their flesh (13% vs. 2%). Analysis of muscle extracts revealed the presence of CTX3C and CTX3B as well as a biotransformed product showing the m/z transitions of 2,3-dihydroxyCTX3C. This is the first experimental evidence of oxidative transformation of an algal CTX in a model consumer and known vector of CTX into the fish food web. These findings that the flesh intended for human consumption carries the majority of the toxin load, and that growth rates can influence the relationship between exposure and accumulation, have significant implications in risk assessment and the development of regulatory measures aimed at ensuring seafood safety.

Evaluation of the Genotoxic and Histological Effects in Neotropical Fish Prochilodus Lacustris (Pisces, Prochilodontidae) in Conservation Area of the Brazilian Northeast.

Human activities significantly impact the aquatic biota in lacustrine environments, leading to negative environmental consequences. Due to this, this study was carried out to evaluate the genotoxic and histological biomarkers in the gills and kidneys of Prochilodus lacustris. The collection of fish and water was conducted in three distinct stations (S1, S2, S3) in an international protected area in northeast Brazil. The histological alterations index was used to assess changes in the gills and kidneys at a histological level. In addition, micronucleus and nuclear abnormalities tests were employed to examine damage to the genetic material. According to the frequency of Micronucleus, nuclear injuries, and the histopathology of gills and kidneys, it can be inferred that station S1 had the highest impact on the fish, causing significant harm. Based on our findings, the organisms residing in Lake Açu are adversely affected by the poor environmental conditions. This raises doubts about the effectiveness of the Protection Area by Humid Zone of International Interest in Northeast Brazil.

The influence of freshwater inflow and seascape context on occurrence of juvenile spotted seatrout Cynoscion nebulosus across a temperate estuary.

Spotted seatrout, a popular recreational sport fish in the southeastern United States, are affected by freshwater flow conditions and the availability of estuarine habitat. However, the relative influence of these factors, particularly on early life stages of seatrout, remains uncertain. We used generalized linear models to quantify relationships between the probability of encountering juvenile spotted seatrout during seine surveys and various factors, including freshwater inflow conditions, the availability and richness of estuarine habitats (seagrass, salt marsh, oyster beds) around (400-m radius) fish collection sites (seascape-scale context), as well as distance to the nearest inlet to the Gulf of Mexico (estuary-scale context) across shallow waters (< 1.5 m depth) of Apalachicola Bay, Florida. Modelling results showed a consistent positive correlation between seagrass area and the probability of encountering juvenile seatrout (all four size classes from 15mm-200mm Standard Length (SL)). The probability of encountering the two smallest juvenile seatrout size classes (15-50mm and 51-100mm SL) was also related to freshwater inflow conditions, particularly within a 3-month period prior to and including peak recruitment. Freshwater inflow may affect early life stages by influencing passive transport of eggs and larvae, planktonic food availability, and predation pressure through increases in turbidity. In contrast, encounter probabilities of the two larger size classes (101-150mm and 151-200mm) were unrelated to freshwater inflow. Inflow-related processes may be less important to the larger juveniles as they have typically settled out of the plankton into benthic habitats which provide refuge from predation and abundant benthic food sources which are not as closely tied to freshwater inflow effects. In addition, models revealed that occurrence of the larger juveniles was related to the availability of nearby habitat types such as oyster beds and salt marshes, suggesting that increased mobility as seatrout grow may allow them to use nearby habitat types as additional sources of food and refuge. These results add to a growing body of literature aimed at understanding the influence of freshwater inflow as well as seascape context on vulnerable juvenile life stages of fishery species to provide more informed strategies for freshwater inflow management and habitat conservation.

Host species and habitat shape fish-associated bacterial communities: phylosymbiosis between fish and their microbiome

BackgroundWhile many studies have reported that the structure of the gut and skin microbiota is driven by both species-specific and habitat-specific factors, the relative importance of host-specific versus environmental factors in wild vertebrates remains poorly understood. The aim of this study was to determine the diversity and composition of fish skin, gut, and surrounding water bacterial communities (hereafter referred to as microbiota) and assess the extent to which host habitat and phylogeny predict microbiota similarity. Skin swabs and gut samples from 334 fish belonging to 17 species were sampled in three Laurentian Great Lakes (LGLs) habitats (Detroit River, Lake Erie, Lake Ontario). We also collected and filtered water samples at the time of fish collection. We analyzed bacterial community composition using 16S metabarcoding and tested for community variation.ResultsWe found that the water microbiota was distinct from the fish microbiota, although the skin microbiota more closely resembled the water microbiota. We also found that environmental (sample location), habitat, fish diet, and host species factors shape and promote divergence or convergence of the fish microbiota. Since host species significantly affected both gut and skin microbiota (separately from host species effects), we tested for phylosymbiosis using pairwise host species phylogenetic distance versus bacterial community dissimilarity. We found significant phylogenetic effects on bacterial community dissimilarity, consistent with phylosymbiosis for both the fish skin and gut microbiota, perhaps reflecting the longstanding co-evolutionary relationship between the host species and their microbiomes.ConclusionsAnalyzing the gut and skin mucus microbiota across diverse fish species in complex natural ecosystems such as the LGLs provides insights into the potential for habitat and species-specific effects on the microbiome, and ultimately the health, of the host.13rgRWqcw5pvG7aonCbZg2Video

Overview on the Biosecurity Measures of Salmonid Fish Farms: A Case Study in Italy

Italy is one of the main European producers of trout fish, and the most important producing area is the Autonomous Province of Trento (APT) in the North East. The objective of the study was to obtain a snapshot of the trout farms of the APT by identifying biosecurity factors, objectifying them, and classifying the establishments accordingly. Data from 62 salmonid farms were collected using a national checklist in which biosecurity elements were identified and assessed using the method of expert elicitation. The purpose was to evaluate the levels of biosecurity of a trout farm in order to rank the risk of introduction and spread of infectious fish diseases. The main critical factors identified during this study were as following: (i) cleaning and disinfection of the cargo truck; (ii) regular collection, storage, and disposal of dead fish; (iii) presence of anti-bird nets; (iv) use of dedicated equipment for the different sectors of the farm; and (v) presence of external areas dedicated to the loading of dead fish.

Spatiotemporal dynamics of duck harvest distributions in the Central and Mississippi flyways, 1960–2019

AbstractGeographical distributions of waterfowl exhibit annual variation in response to spatiotemporal variation in weather conditions, habitat availability, and other factors. Continuing changes in climate and land use could lead to persistent shifts of waterfowl distributions, potentially causing a mismatch with habitat conservation planning, wetland restoration efforts, and harvest management decisions informed by historical distributions. We used band recoveries and harvest records (i.e., hunter‐harvested wings) from the United States Fish and Wildlife Service Waterfowl Parts Collection Survey as indices of duck distribution in autumn and winter, and quantified intra‐annual, interannual, and interspecific variation in their geographic distributions across 6 decades (1960–2019) for 15 duck species in the Central and Mississippi flyways in North America. Specifically, we tested for annual and decadal shifts in mean latitude and longitude of recoveries for each month (Oct–Jan) by species and taxonomic guild (i.e., dabbling, diving ducks). Overall, species varied in the extent, timing, and sometimes direction, of distributional change in recoveries. From 1960–2019, mean recovery locations for dabbling ducks shifted south 105–296 km in October and 27 km in November (wings only), whereas mean latitudes shifted north 144–234 km in December and 186–301 km in January. Mean recovery locations for diving ducks shifted north 162 km in October (wings only), 84–173 km in December, and 66–120 km in January, but shifted 99–512 km south in November. Shifts in longitude were less consistent between guilds and data types. Finally, distributional change rarely accelerated during recent decades, except for southward shifts of band recoveries of diving ducks in November and northward shifts of band and wing recoveries of dabbling ducks in January. Although anecdotal accounts of large‐scale northward shifts in duck distributions are prolific in the land management and hunting communities, our data demonstrate more subtle shifts that vary considerably by species and month. Observed changes in recovery distributions could necessitate changes in timing of habitat management practices throughout the Central and Mississippi flyways and may result in fewer hunting and recreational opportunities for some species in southern states. Quantifying patterns of historical change is a necessary first step to understanding temporal and interspecific variation in waterfowl distributions, which will help with landscape‐scale conservation and management efforts in the future and enable effective communication to core constituencies regarding ongoing changes and their implications for recreational engagement.

Fish in Burial Practice of the Sargat Culture Population of the Early Iron Age of the Baraba Forest-Steppe (According to the Materials of the Mound No. 51 of the Ust-Tartas Burial Ground)

Purpose. The Sargat culture fish remains are still given very little attention. The purpose of this work is to present materials that testify to the use of fish in the burial practice of the Sargat population of Baraba.Finds (artefacts). In the field season of 2022, the Toguchin team of the IAET SB RAS explored the mound no. 51 of the Ust-Tartas burial ground of the Sargat culture. Among the various artifacts found on the mound territory there were objects containing animal bones, and objects containing fish remains, as well as objects containing both animal bones and fish remains.Methods. Preparation of the osteological collection of fish remains was carried out in 2022–2023 using a cameral processing method. The collection contains mainly scales, bones of the visceral part of the skeleton of the head, bones of the skull. Fragments of the axial skeleton (vertebrae, Weberian apparatus, urostyle) and pharyngeal teeth appear in a smaller number. In the pocess of the collection formation, it was found that the best preservation of samples is ensured by materials that have not been preliminary washed and cleaned: the bone structures are less brittle. Therefore, fragments of the fish skeleton were separated from the soil in the laboratory.Results. For the most part, accumulations of fish remains are represented by large specimens of older age groups (from 7+ years, mostly 10+ and more). The identified species composition of fish in samples of the Early Iron Age includes representatives of the family Cyprinidae (ide Leuciscus idus, goldfish Carassius gibelio) and family Percidae (perch Perca fluviatilis). In addition to the listed species, remains of the family Acipenseridae (sterlet Acipenser ruthenus) and the family Cyprinidae (golden crucian carp C. Carassius) were noted in the earlier objects. Object 10 stands out: it is a butt containing not only tools and animal bones, but also fish remains. For the first time, the fact of fish use in the funeral rite of the Sargatians was revealed. The fish remains in the mound testify that the population of the Sargat culture who created this site practiced fishing along with their main occupation – cattle breeding.Conclusion. Materials of the mound no. 51 of the Ust-Tartas burial ground, containing fish remains, are an example of the local population adaptation to the natural environment. The Tai tract was a natural oasis, which not only provided a forage base for livestock but also ensured an easy catch of fish. Human adaptation to the natural conditions in the Baraba region was quite successful, as evidenced by the fact that fish was a part of the funeral rite along with products of animal origin. It was often included in butts in some objects, which correlates with sacred actions.

Multi-Criteria Decision-Making for Water Resources Planning Using the MOORA Method

Water Resources Planning. Systems with water resources have benefited people and their enterprises for a very long time. Many services are provided by these systems. But in many regions around the globe, people are Infrastructure that is inappropriate, insufficient, or in poor condition, excessive river flow withdrawals, pollution from agricultural and industrial operations, nutrient loadings that cause eutrophication, salinization from ground water flows, insect infestation of exotic animals and plants, excessive fish foraging, flood simple and habitat modification from development activities, but rather modifications in water quality and sediment flow regimes are some of the typical causes. Systems for managing water resources have long benefited Individuals and their economy. These systems provide a variety of services. But, they cannot meet all but the most basic needs for sanitization and drinking water in many regions of the world. Moreover, many of these water resource management regimes are unable to support and encourage resilient biodiverse ecosystems. Common causes include inappropriate, insufficient, and/or deteriorated infrastructure, excessive river flow withdrawals, pollution from agricultural and industrial operations, nutrient enrichment brought on by nutrient applied loads, salinization from groundwater recharge stream, infestations of exotic plants and animals, extreme fish collecting, flood plain and vegetation modification caused by construction events, and needs changing in water and sediment flow conditions. Decision Making (MODM) techniques are actually available, and this newsletter is prepared to introduce the new MODM methodology. Cross optimization ratio analysis in essence Unique AMS selection problems are resolved by the (MOORA) method in the context of real-time manufacturing. Using the method of the most objective reference point, house is one of MOORA's components. On the question of the owners' consumer sovereignty, several reservations may be made. Pre-SMART cost to complete (dollars), Post-SMART cost to complete (dollars), Dollars saved, Time saved (months). Ala Wai, Espanola Valley, LA River, Lower San Joaquin River, Missouri River degradation. “from the result it is seen that Ala Wai and is got the first rank whereas is the LA River got is having the lowest rank.” The value of the dataset for Water Resources Planning in MOORA method shows that it results in Ala Wai and top ranking”.

Ichthyofauna in the Lomami National Park and Its Hinterlands, Democratic Republic of the Congo

This investigation deals with freshwater fish populations in thirteen sampling rivers of Lomami National Park (LNP) and its hinterlands. The study aimed to inventory the ichthyofauna in freshwater bodies of LNP and its hinterlands; determine fish species with high economic value according to preference by riparian communities; and assess the conservation status of fish species. Intensive fish sampling was conducted thirteen rivers of LNP and its hinterlands using gill nets with stretched mesh sizes of 9.5, 10, 12, 15 and 20 mm in 2016. A survey questionnaire was administered to fishermen in order to determine fish species with high economic value. A total of 2985 fish were caught in thirteen rivers belonging to 129 species, 54 genera, 20 families and 8 orders. The family of Mormyridae dominated in the fish collection with 30 species followed by family of Alestidae with 23 species. Clarias spp., Schilbe spp., Chrysichthys spp., Auchenoglanis occidentalis, Polypterus spp., Hydrocynus spp., Alestes spp., Parachana spp. and species of Mormyridae were recorded as fish species with high economic value. The majority of species was least concerned, but one was reported as endangered species (Nannothrissa sterwarti) and another vulnerable (Labeo rectipinnis). The analysis displayed that all rivers were diverse with a minimum observed in the Onema River. The probability of catching two individuals of different species in the same river was high in all rivers, but it was higher in the Amboko, Lodja, Lomami and Yalo Rivers (96%); and it was slightly low in the Onema River (73%). The Kruskal–Wallis result showed statistical differences among sampling rivers (P = 0.0000).&#x0D; Our findings provided valuable information for the conservation and management of fish species in the freshwater of Lomami National Park and its hinterlands.

Changing Economic Strategies in the Ecsed Marsh

The Ecsed Swamp was formed in the New Holocene Era in the lowest areas of Nyírség and Szatmár Plains. Besides the protective nature of the swamp, it was a significant source of livelihood for the local population – loach fish collecting (csikász), bird hunting and egg collecting (pákász) were the main occupations of the “swamp people”. The Ecsed Swamp, which once covered almost 432 km2 was drained at the end of the 19th century that caused significant changes in everyday life and farming. The inhabitants of the so-called “Loach land” (Csíkország) tried to dig up and cultivate marshy areas even before the drainage. Burning, cutting and cleaning were already known among the swamp people, since this was the only way to carry out farming activities in this area. In their frustration the swamp people effected by the drainage tried to obtain land for cultivation. They worked on the lands purchased by the Károlyi noble family. More prosperous ones also built farms on the border of the neighbouring villages, thus the process of homesteading began. In the 21st century, the cultivation of agricultural land in the area of former swamps is causing significant problems since water shortage is now characteristic towhole Europe. Reedfires in the former swamp areais a phenomenon that exists to this day. With the transformation of landscape and ways of farming and living, the need to apply different economic strategies arose, which I will discuss t in my research study with case studies from the 19th and 21st centuries.

Morphological differences between wild and hatchery‐reared Bloater (Coregonus hoyi) from Lake Michigan, USA

AbstractCoregonines (ciscoes and whitefishes) are economically, ecologically, and culturally important fishes that are distributed throughout the Northern Hemisphere. In the Laurentian Great Lakes, coregonines declined throughout the 19th and 20th centuries, and managers have prioritized their restoration. A key restoration tool is reintroduction via stocking. However, hatchery‐reared coregonines can display different morphologies than wild fish, which could affect their fitness. Unfortunately, our understanding of these differences is limited because previous work did not adequately remove allometric effects in morphological analyses. We compared morphologies between wild and hatchery‐reared Bloater (Coregonus hoyi) from the same stock using appropriate size corrections. Hatchery‐reared fish had shorter heads, shorter dorsal fins, and shallower bodies than wild fish. Moreover, some characters differed across wild fish collections. Our results improve our understanding of how artificial rearing can impact coregonine morphology, and we recommend future studies on what causes these differences and whether they impact fitness.

From historical expedition diaries to whole genome sequencing: A case study of the likely extinct Red Sea torpedo ray

AbstractTorpedo rays (Torpedinidae, Torpediniformes) are small to moderately large batoids that produce an electric discharge. They are distributed worldwide in temperate and tropical seas and are, as a result of their bottom‐dwelling behaviour, susceptible to trawl fishing and often end up as victims of bycatch. The distribution ranges of most recognized species seem to be restricted; however, their species‐level systematics is not adequately resolved. In the genus Torpedo, in which many species require revision, there are possibly several undescribed species, while numerous misidentifications add to the complexity of the issue. In the latest lists of living rays, 13 species are accepted in the genus Torpedo, including three of doubtful validity and several recently discovered undescribed species. Among the valid species is the critically endangered, possibly extinct, Torpedo suessii Steindachner, 1898, the Red Sea torpedo, of which only four specimens have been recorded in the literature until now, three of which still exist in the fish collection of the Natural History Museum of Vienna. Museum collections are the most important archive of biodiversity on Earth, and are increasingly being used for various studies, including phylogenetics, population genomics, and biogeography. Nevertheless, molecular analysis of old museum material remains challenging because the genetic material has degraded, is fragmented, and of low quantity. In molecular taxonomy, the necessity of including type specimens as name‐bearing specimens is increasingly recognized. Here, the extended specimen approach was applied to re‐describe the lectotype of T. suessii. The approach included research of historical information and whole genome sequencing, followed by genome assembly and phylogenetic analysis.

Numerical Study on Fish Collection and Transportation Facility with Water Temperature Compensation

Fish collection and transportation facilities have been widely constructed as man-made passages that allow fish to bypass dams. These facilities usually provide proper conditions that attract and gather fish inside, and then transport them upstream over the dam. A novel design that includes water temperature compensation was presented, and the velocity, temperature distribution, and turbulent kinetic energy inside the fish collecting channel were studied using numerical tools. The facility mixes the warm cooling water from the electrical transformer with the tailwater in order to reduce the negative ecological effect of the low-temperature discharge. It can operate under a 2 m water level range in the tailrace channel. The numerical results show that the temperature inside the fish collecting channel increased by about 2 °C and settled within the suitable range of the target fish species. The water body maintained a relatively uniform and steady temperature. The velocity and the turbulence kinetic energy (TKE) field near the fish entrance were distinct from those of the background and were beneficial for fish migration. This study could potentially motivate ecological engineers to mitigate the negative impacts of low-temperature tailwater from hydropower plants when designing fish collection and transportation facilities.

Five new ocellus-bearing species of the cusk-eel genus Neobythites (Ophidiidae, Ophidiiformes) from the West Pacific, with establishment of three new species groups.

Five new West Pacific species of the cusk-eel genus Neobythites (Ophidiidae) from the lower shelf and upper slope of the Solomon Sea, off Okinawa, Japan, and off Fiji are described. The descriptions are based on nine specimens from three fish collections and unvouchered fresh colour photographs showing three specimens taken shortly after being caught. The new species all bear at least one ocellus on the dorsal fin, a conspicuous colour pattern consisting of a dark spot surrounded by a contrasting white or pale ring. Fifteen ocellus-bearing congeners are rather similar with at least one of the new species, requiring detailed comparisons based on a large set of morphometric, meristic, colour and otolith-shape data from over 300 specimens. To facilitate the comparisons among the 20 Neobythites species in total and the preparation of identification keys, three new taxonomic species groups, the australiensis, kenyaensis and longiventralis groups, are established. Also, the steatiticus species group which had been previously established, is slightly updated. A key for identification of each of these four groups is prepared. The most important characters for distinction among groups are the presence and number of preopercular spines, the number and position of ocelli, and pelvic-fin length. For each of the three new groups, species accounts including new species descriptions, within-group comparisons, and identification keys are prepared. For the steatiticus group, only the description of the new species, N. pako n. sp., and an updated account of the Atlantic N. monocellatus are provided, considering previously published accounts of the other seven species in comparisons with those two species and the identification key. The results are shortly discussed, emphasizing the finding of a unique ocellus structure in N. superocellatus n. sp. (australiensis species group) and the need for taxonomic studies of the remaining 10 ocellus-bearing species of Neobythites together with additional, non-ocellus-bearing congeners.

Life support systems and aquatic communities in public aquariums

The Pangandaran Integrated Aquarium and Marine Research Institute (PIAMARI) was developed in Pangandaran, and is equipped with public aquarium facilities. The Main Aquarium is an oceanarium in the form of a box, with a volume of 1.238 million liters, and accommodates various marine biota. This paper aims to provide an overview of the life support system used and the aquatic communities in the Main Aquarium. An inventory of principal components and equipment, the composition of biota, plankton, and ectoparasites was conducted in the oceanarium. The Main Aquarium is supported by filtration using a sand filter, protein skimmer, and an ozone generator. Water quality is maintained using the filtration combined with partial water changes. There are nine species of fish, including sharks and rays, and two species of turtles that are kept in the oceanarium, where most of the collections are omnivores, with IUCN LC conservation status and the rest NT to CR. Seven plankton genera were identified in the oceanarium (H’:1.78 and E: 0.90). There was Cryptocaryon ectoparasite infestation on the gills and skin of Trachinotus blochii with open lesions. Fish collections show different behavior and consume the fresh and artificial feed. Apart from being an edu-tourism facility, the oceanarium can act as a place for living and ex-situ culture for endangered marine biota.

Restoration of a fish-attracting flow field downstream of a dam based on the swimming ability of endemic fishes: A case study in the upper Yangtze River basin

The construction of fish passage facilities can mitigate the negative effects of dams and other water engineering construction on river connectivity and have a significant positive effect on the conservation of local fish diversity. To attract target fishes into fish passage facilities effectively, the optimal flow velocity range to attract fish must be determined. Three local endemic species of the Mishi Reservoir were considered as the protection targets. However, their swimming abilities remain unclear. Therefore, the induced swimming speed (Uind), critical swimming speed (Ucrit) and burst swimming speed (Uburst) of three fish species were tested. Based on these results, we identified the optimal flow velocity to attract fish, which falls within the range of 0.15–0.51 m/s. A validated three-dimensional hydrodynamic model was used to simulate different schemes. By comparing the flow field simulation results of different schemes, we obtained the optimal measure to restore the flow field, namely, a multiple engineering measure combining increased the fish attraction flow in the fish collection pond and the construction of a spur dike. This study offers a solution for the specific case and enhances the database of swimming characteristics of endemic fish in the upstream reaches of the Yangtze River. It also provides a valuable reference for designing fish-attracting flows and potential measures for restoring flow fields in similar future projects.