Studies Of Freshwater Fish Research Articles

Naming the other cousin: A new goldie barb (Cyprinidae: Smiliogastrininae) from the northeast escarpment in South Africa, with proposed taxonomic rearrangement of the goldie barb group in southern Africa.

A growing body of evidence indicates that the global diversity of freshwater fishes has not been fully documented. Studies of freshwater fishes that were previously thought to be morphologically variable have revealed the existence of deeply divergent lineages, with many distinct species. In southern Africa a number of Enteromius species exhibit either exceedingly wide or divided distribution patterns that should be rare for freshwater fishes with limited dispersal opportunities between river systems. One such species is the sidespot barb, Enteromius neefi. As currently defined, E. neefi has a disjunct distribution that is divided between rivers in the northeast escarpment in South Africa and Eswatini, and tributaries of the Upper Zambezi in Zambia and southern Congo in the Democratic Republic of Congo, with a large geographic gap between these two populations. With the use of molecular and morphological methods, the level of divergence between the two populations was examined, and a new species was described from the Steelpoort River in the Limpopo River system of South Africa. Findings from this study provide further evidence for a number of taxonomic problems within the goldie barbs of southern Africa, and some taxonomic rearrangements are proposed for this group.

Patterns of ichthyofaunal diversity and distribution across Jebba Hydro-Electric Power (HEP) dam, Jebba, north-central Nigeria.

The ichthyofauna diversity of the Jebba Hydroelectric Power (HEP) Dam, Jebba, North-central Nigeria was studied. Fishes were sampled for 24 months using gill net, hook and line, and cast net. Individuals were identified using morphological and molecular (mitochondrial Cytochrome c Oxidase subunit I) data. A total of 9605 freshwater fishes were recorded during the sampling period. The use of an integrative taxonomic approach enabled the identification of 83 species belonging to 42 genera. Additionally, the study recorded three unidentified species - Ctenopoma sp, Malapterurus sp., and Protopterus sp. Analyses showed that individuals belonging to families Cichlidae and Mochokidae dominated the dam. The diversity analyses revealed relatively high fish diversity during the rainy season at the downstream section of Jebba HEP dam compared to the upstream section. The study, therefore, showed the presence of a diverse fish community comprising high species richness and diversity across the Jebba HEP dam. Finally, we recommend proper biodiversity monitoring and assessment of freshwater fish diversity across Nigeria. In addition, the use of an integrated taxonomic approach is recommended for appropriate species' identification and studies of freshwater fishes from Nigeria.

Fishes from the Miocene lacustrine sequence of Bełchatów (Poland)

ABSTRACT The paper deals with results of the study of freshwater fish remains obtained from the Miocene deposits of Bełchatów open-cast brown coal mine in 1984 and 1986. These fossils are represented mainly by numerous disarticulated bones which are assumed as belonging to cyprinid (Tinca sp.) and esocids (Esox sibiricus, Esox sp.), as well as to indeterminate bony fishes (Teleostei indet.). The find of the Siberian pike described herein is the oldest occurrence of this species in Europe, and allows extending its previously known range to the west. Some aspects of the palaeogeography and palaeoecology of the late early Miocene fish assemblage of Bełchatów with reference to the distribution of E. sibiricus are discussed.

Artificial propagation of the endangered Rumanian endemic warm water rudd (Scardinius racovitzai Müller 1958, Cyprinidae, Cypriniformes) for conservation needs

Scardinius racovitzai appeared to be locally adapted to an extreme high temperature environment (26–35 °C). As a species of conservation concern, due to declining ecological condition of the solitary thermal lake it could be found in (Lake Petea, Oradea, Romania) and eventual near complete abstraction of this lake, 60 adults were saved in 2014. In this study we investigated methods for induced spawning and sperm cryopreservation to aid recovery and reintroduction to restored habitats. Induced spawning was introduced successfully by intraperitoneal induction of dried carp pituitary extract and human chorion gonadotropin. Larvae and juveniles were successfully reared to age 3 months using standard methods for cyprinids. Our experiments on the cryopreservation of S. racovitzai sperm show that the extender consisting 40 mM KCl 200 mM glucose, 30 mM Tris buffered with HCL pH 8.0 is suitable for freezing warm water rudd sperm together with methanol as a cryoprotectant. By rescuing the remaining wild stock into captivity and undertaking propagation research we have prevented extinction of this rare species – more so S. racovitzai will be important in the study of freshwater fishes and how they can adapt to significant warming.

Feeding Microhabitat Use and Selectivity of JuvenileMugil cephalus(Actinopterygii: Mugilidae) in a Hawaiian Stream

Understanding microhabitat use of an organism is an important first step to understanding its ecology and also provides critical information for guiding management and conservation efforts. Most microhabitat studies of freshwater fishes have focused on temperate systems, with far less research on fish microhabitat use in tropical streams. Here, we studied microhabitat use and selectivity patterns of juvenile Mugil cephalus within a Hawaiian stream, USA (Waiāhole Stream, latitude: 21.48°, longitude: -157.85°). We measured depth, velocity, substrate composition, and canopy cover at locations where M. cephalus was observed feeding and compared attributes of these locations to microhabitat available to the fish. We found significant differences in microhabitats where mullet fed compared to microhabitats available, with feeding occurring in microhabitats with moderate velocities (0.21–0.60 m/sec), shallow to moderate depths (0.31–0.80 m), gravel and pebble as dominant substrates, and low canopy cover. Results of our study suggest that juvenile M. cephalus are selecting erosional habitats and avoiding depositional habitats, a result that was also supported by a multivariate analysis of habitat selectivity. Our data corroborate results of other studies reporting that fish grazers select habitats that are clean (erosional) rather than silted (depositional). Knowing how M. cephalus in streams use the available habitats is important for understanding how to manage freshwater habitat to support juvenile M. cephalus in the face of increasing anthropogenic impacts and a changing climate.

Variation in freshwater fish assemblages along a regional elevation gradient in the northern Andes, Colombia.

Studies on elevation diversity gradients have covered a large number of taxa and regions throughout the world; however, studies of freshwater fish are scarce and restricted to examining their changes along a specific gradient. These studies have reported a monotonic decrease in species richness with increasing elevation, but ignore the high taxonomic differentiation of each headwater assemblage that may generate high β-diversity among them. Here, we analyzed how fish assemblages vary with elevation among regional elevation bands, and how these changes are related to four environmental clines and to changes in the distribution, habitat use, and the morphology of fish species. Using a standardized field sampling technique, we assessed three different diversity and two structural assemblage measures across six regional elevation bands located in the northern Andes (Colombia). Each species was assigned to a functional group based on its body shape, habitat use, morphological, and/or behavioral adaptations. Additionally, at each sampling site, we measured four environmental variables. Our analyses showed: (1) After a monotonic decrease in species richness, we detected an increase in richness in the upper part of the gradient; (2) diversity patterns vary depending on the diversity measure used; (3) diversity patterns can be attributed to changes in species distribution and in the richness and proportions of functional groups along the regional elevation gradient; and (4) diversity patterns and changes in functional groups are highly correlated with variations in environmental variables, which also vary with elevation. These results suggest a novel pattern of variation in species richness with elevation: Species richness increases at the headwaters of the northern Andes owing to the cumulative number of endemic species there. This highlights the need for large-scale studies and has important implications for the aquatic conservation of the region.

Setting water quality objectives for the health of freshwater fish

An important responsibility of the Environment Protection Authority, Victoria, is to set objectives for levels of environmental contaminants. To support the development of environmental objectives for water quality, a need has been identified to understand the dual impacts of concentration and duration of a contaminant on biota in freshwater streams. For suspended solids contamination, information reported by Newcombe and Jensen [North American Journal of Fisheries Management, 16(4):693--727, 1996] study of freshwater fish and the daily suspended solids data from the United States Geological Survey stream monitoring network is utilised. The study group was requested to examine both the utility of the Newcombe and Jensen and the USA data, as well as the formulation of a procedure for use by the Environment Protection Authority Victoria that takes concentration and duration of harmful episodes into account when assessing water quality. The extent to which the impact of a toxic event on fish health could be modelled deterministically was also considered. It was found that concentration and exposure duration were the main compounding factors on the severity of effects of suspended solids on freshwater fish. A protocol for assessing the cumulative effect on fish health and a simple deterministic model, based on the biology of gill harm and recovery, was proposed. References D. W. T. Au, C. A. Pollino, R. S. S Wu, P. K. S. Shin, S. T. F. Lau, and J. Y. M. Tang. Chronic effects of suspended solids on gill structure, osmoregulation, growth, and triiodothyronine in juvenile green grouper epinephelus coioides. Marine Ecology Press Series, 266:255--264, 2004. J.C. Bezdek, S.K. Chuah, and D. Leep. Generalized k-nearest neighbor rules. Fuzzy Sets and Systems, 18:237--26, 1986. E. T. Champagne, K. L. Bett-Garber, A. M. McClung, and C. Bergman. {Sensory characteristics of diverse rice cultivars as influenced by genetic and environmental factors}. Cereal Chem., {81}:{237--243}, {2004}. S. G. Cheung and P. K. S. Shin. Size effects of suspended particles on gill damage in green-lipped mussel perna viridis. Marine Pollution Bulletin, 51(8--12):801--810, 2005. D. H. Evans. The fish gill: site of action and model for toxic effects of environmental pollutants. Environmental Health Perspectives, 71:44--58, 1987. G. C. Grigg. The failure of oxygen transport in a fish at low levels of ambient oxygen. Comp. Biochem. Physiol., 29:1253--1257, 1969. G. Holmes, A. Donkin, and I.H. Witten. {Weka: A machine learning workbench}. In Proceedings of the Second Australia and New Zealand Conference on Intelligent Information Systems, volume {24}, pages {357--361}, {Brisbane, Australia}, {1994}. {IEEE Computer Society}. D. D. Macdonald and C. P. Newcombe. Utility of the stress index for predicting suspended sediment effects: response to comments. North American Journal of Fisheries Management, 13:873--876, 1993. C. P. Newcombe. Suspended sediment in aquatic ecosystems: ill effects as a function of concentration and duration of exposure. Technical report, British Columbia Ministry of Environment, Lands and Parks, Habitat Protection branch, Victoria, 1994. C. P. Newcombe and J. O. T. Jensen. Channel suspended sediment and fisheries: A synthesis for quantitative assessment of risk and impact. North American Journal of Fisheries Management, 16(4):693--727, 1996. C. P. Newcombe and D. D. Macdonald. Effects of suspended sediments on aquatic ecosystems. North American Journal of Fisheries Management, 11(1):72--82, 1991. K. Schmidt-Nielsen. Scaling. Why is animal size so important? Cambridge University Press, NY, 1984. J. S. Schwartz, A. Simon, and L. Klimetz. Use of fish functional traits to associate in-stream suspended sediment transport metrics with biological impairment. Environmental Monitoring and Assessment, 179(1--4):347--369, 2011. E. Al Shaw and J. S. Richardson. Direct and indirect effects of sediment pulse duration on stream invertebrate assemblages and rainbow trout (Oncorhynchus mykiss) growth and survival. Canadian Journal of Fish and Aquatic Science, 58:2213--2221, 2001. P. Tiwari and H. Hasegawa. {Demand for housing in Tokyo: A discrete choice analysis}. Regional Studies, {38}:{27--42}, {2004}. Y. Tramblay, A. Saint-Hilaire, T. B. M. J. Ouarda, F. Moatar, and B Hecht. Estimation of local extreme suspended sediment concentrations in california rivers. Science of the Total Environment, 408:4221--

Using radio telemetry to evaluate the depths inhabited by Murray cod (Maccullochella peelii peelii)

Radio telemetry is widely used in studies of freshwater fishes, but the vertical position of fish in riverine environments is rarely reported. The present study tested the application of radio transmitters fitted with depth sensors to determine the vertical position of Murray cod in the lower Ovens River in south-eastern Australia. As the scale of depths in rivers is usually limited (<10 m in the present study), there is a greater need to assess measurement error. The study first involved trials to define depth measurement errors, and a mean relative bias of 9% (range 1.5–14.8%) towards greater depth was recorded. These data were then used to correct the depths recorded from tagged fish. Although data from this preliminary study are somewhat limited, results from the tagged fish showed that by day they all occupied the lower 15% of the water column, indicating that Murray cod exhibit demersal behaviour, using bottom rather than mid-water habitats. Although the present study highlights the importance of tag trials in determining errors, it also indicates the potential application of this technique to understanding the depth-integrated habitat preferences of Murray cod and other species.

“Handbook of European freshwater fishes” by M. Kottelat and J. Freyhof (2007)

Publications Kottelat, P.O. Box 57, CH-2952 Cornol, Switzerland. E-mail: publications_kottelat@bluewin.ch. X + 646 pp. ISBN 978 2 8399 0298 4. This book focuses on 546 native freshwater fishes (including 56 new species described since 2000) and 33 introduced species in Europe (west of the Ural Mountains). It includes photographs, taxonomic keys, distribution maps and other useful information: morphology, habitats, ecology, and conservation notes. It covers more species and a wider area (especially around Russia) than the preceding book, European Freshwater Fishes, by the first author, published in 1997. The most appreciated feature of the book is that it incorporates as many color photographs of living fishes and as much information about their conservation status as possible. In addition, it provides introductory information about the biology of freshwater fishes at the beginning, in addition to a detailed bibliography on freshwater fishes in Europe and a glossary, both of which are also useful for researchers engaged in studies of freshwater fishes. This book is available directly from the authors.

IN MEMORIAM: GUNNAR SVÄRDSON, 1914–2004

Gunnar Svardson, Professor Emeritus at the Freshwater Laboratory, Drottningholm, Sweden, and Corresponding Fellow of the AOU, was born on 19 September 1914 in Stockholm. He celebrated his 90th birthday shortly before his unexpected death in Stockholm on 6 November 2004. He was one of Sweden's best known and most highly respected evolutionary biologists and ornithologists. His strong interest in natural history emerged early. After finishing school, he studied zoology, botany, and geography at the University of Stockholm. Like many biologists, he started out primarily as bird watcher and had lifelong passion for ornithology. Yet his best-known scientific contributions were based on studies of freshwater fish. In 1945 he presented his doctoral thesis, titled simply Chromosome Studies on Salmonidae. In his thesis, which is still cited, focused on a of whitefish (Coregonus) in Scandinavian freshwaters and demonstrated that it actually consisted of up to half dozen genetically incompletely isolated populations, each adapted to certain set of environmental circumstances. The introgression of genes into each of them from one or more of the others prevented their definite fission and kept them in state of lasting incipiency. Svardson's work led to an entirely novel appreciation of the evolutionary history, genetics, and systematics of the genus Coregonus, and to day it provides one of the most fascinating and intriguing examples of the dynamics of speciation in population groups. applied an impressive array of methods and concepts, including cytology, biogeography, and behavior. A similar approach was later used by him to study other groups of salmonids and by other researchers for great variety of other animal taxa. Moreover, in today's world of biotic globalization and violent anthropogenic perturbations of animal and plant communities, Svardson's insights into the processes of species formation and splitting have received increased attention. Hybridization is widely regarded as one of the theoretically and practically most important phenomena in population genetics, as well as in the struggle to preserve the world's biodiversity. As the ideas of the Modern Synthesis reached Scandinavia during and after the war, was one of the few who quickly realized the fundamental significance of new way of thinking and became its leading proponent and defender in Sweden. Breaking as they did with the Linnaean tradition of systematics in Sweden, the new ideas aroused acrimonious feelings in wide and influential circles, and was involved in many heated arguments. It is truly refreshing to read his crystal-clear contributions to debate, and more than almost anything he published, those texts show him decades ahead of his time. Very little would have to be changed to make these publications reflect today's state of the art in evolutionary biology. Another major contribution flowed from Svardson's detailed familiarity with birds and bird communities in Scandinavian forests. In comparatively brief paper in Oikos (1949), he presented an innovative model of the different evolutionary and ecological consequences of intraspecific and interspecific competition. Although based on bird work, the general applicability of the model was quickly realized in many quarters, and more than one of the most prominent (if aging) ecologists of the late 20th century have in conversations mentioned to me that Svardson 1949 was major eyeopener for them and greatly influenced their own research in community once related to me that particular paper had been summarily rejected by the editor-inchief of the new journal, with the argument that this is not ecology. In those days, long before MacArthur, the attitude in Scandinavia was that

Development and intercalibration of methods in nordic freshwater fish monitoring

The awareness of the effects of transboundary pollution has increased the necessity to use comparable methods and to initiate joint studies between countries in environmental monitoring. In freshwater fish monitoring a number of different methods have been used, strongly reducing the possibilities to comparative assessments between countries. In 1990, a workshop on freshwater fish sampling was initiated in order to develop and intercalibrate methods used in freshwater fish studies in the Nordic countries. During a three year period, a new type of multi-mesh gillnet to be used for fish monitoring in Norway, Finland and Sweden have been developed. Comparative studies and gillnet-selectivity assessments show that these new multi-mesh gillnets better describe the actual population structure of European perch (Perca fluviatilis), roach (Rutilus rutilus) and Arctic char (Salvelinus alpinus) than do the traditional gillnet series used in the Nordic countries. Ageing of fish is central in most environmental studies, however, the comparability of analyses performed at different laboratories may be low. Comparative age analyses between the three countries have been performed for a number of fish species. The results of ageing E. perch, whitefish (Coregonus sp.) and roach indicate that differences between laboratories can be reduced by intercalibration. In the future, the workgroup will be focused on a further development of joint methods within studies of freshwater fish and on joint intemordic assessments on species distribution, abundance and life history characteristics in relation to airborne pollutants and liming.

Accumulation and discharge behavior of Cs-137 by zebra fish (Brachydanio rerio) in different aquatic environments

The uptake and release kinetics of137Cs from water by the tropical fishBrachydanio rerio has been studied under controlled laboratory condition. The accumulation of this radionuclide from food was avoided by feeding the fishes separately in an inactive environment. A steep inverse dependence of bioconcentration factor (BCF) with potassium concentration has been observed. This can formally be described by the equation BCF=5.2 · [K+]−0.44. The elimination rate constant K in fresh water conditions has been found to have a magnitude of 0.014±0.03 d−1 which corresponds to a biological half-life of 51±10 days. The uptake and release kinetics ofBrachydanio rerio has been compared with earlier studies of fresh water fishes.

Behavioural studies of freshwater fishes during a solar eclipse

Effects of a total solar eclipse on fish have rarely been recorded. Three freshwater fish species — Amphipnous cuchia, Anabas testudineus and Colisa fasciata were studied during the past total solar eclipse on February 16, 1980. Behavioural studies pertaining chiefly to fish movement, fish breathing and colouration were made, and possible reasons for effects are discussed.