Variations in the infection level of Neoergasilus japonicus (Copepoda: Ergasilidae) between freshwater fishes at different sites in the Ashida River system, western Japan

Zoosymposia ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 106-116 ◽  
Author(s):  
KAZUYA NAGASAWA ◽  
AKIKO INOUE
Keyword(s):  
Fish Species ◽  
Water Depth ◽  
River System ◽  
Freshwater Fishes ◽  
Current Speed ◽  
Main Stream ◽  
Infection Level ◽  
Western Japan ◽  
Native Fishes ◽  
Neoergasilus Japonicus

Females of Neoergasilus japonicus (Harada, 1930) are ectoparasitic on freshwater fishes. While this species is currently known as an alien parasite in southern Asia, Europe, and North America, little information is as yet available on its ecology. In this study, we investigated the occurrence of N. japonicus on freshwater fishes in the Ashida River system in Hiroshima Prefecture, western Japan, in order to evaluate which factors may contribute to variations in the infection level of this parasite between fish species and between sampling locations. Sampling was conducted at five sites in the middle and lower reaches of the Ashida River (the main stream) and at two sites of its tributary, the Takaya River. Twenty-three fish species belonging to seven families were collected, of which ten (eight native and two introduced) benthopelagic species were found infected with N. japonicus. Two centrarchid species of North American origin, largemouth black bass Micropterus salmoides and bluegill Lepomis macrochirus, were more frequently and heavily infected than Japanese native fishes. In both introduced and native fishes, larger individuals showed a higher level of infection. For the fish species that were widespread in the main stream, infection with N. japonicus occurred in the lower reaches only, where current speed was nil and water depth was high. These results suggest that the fish composition, biological aspects (e.g., body size and distribution in the water column) of the fish hosts, and environmental factors such as current speed and water depth are closely associated with the distribution pattern of N. japonicus in the Ashida River system.

scholarly journals Ichthyofaunal diversity in the upper-catchment of Kabini River in Wayanad part of Western Ghats, India

2021 ◽  
Vol 13 (2) ◽  
pp. 17651-17669
Author(s):  
Dencin Rons Thampy ◽  
M.R. Sethu ◽  
M. Bibin Paul ◽  
C.P. Shaji
Keyword(s):  
Fish Species ◽  
Western Ghats ◽  
Native Species ◽  
River System ◽  
Freshwater Fishes ◽  
Iucn Red List ◽  
Cauvery River ◽  
True Diversity ◽  
Distribution Ranges ◽  
The Western Ghats

We present here a detailed account of the diversity, distribution, threats, and conservation of freshwater fishes in the upper-catchment of the Kabini River in the Wayanad part of the Western Ghats Biodiversity Hotspot.  A total of 136 fish species belonging to 13 orders, 29 families, and 69 genera were recorded.  Order Cypriniformes dominated with five families, 36 genera, and 84 species, and Cyprinidae was the dominant family represented by 51 species within 21 genera.  The true diversity of ichthyofauna in this catchment, is still unclear and requires further exploration and taxonomic studies.  At least 44 species recorded during the study are endemic to the Western Ghats, of which 16 are endemic to the Cauvery River System and two species endemic to the Kabini Catchment.  A total of 20 non-native fish species were recorded from the study area, of which six species were inter-basin (within India) transplants and 14 species were exotic.  Among the native species with confirmed identity, four are Critically Endangered (CR) and nine Endangered (EN) as per the IUCN Red List of Threatened Species.  As a part of the study, we also extend the distribution ranges of Opsarius malabaricus, Laubuka trevori, Opsarius bendelisis, Puntius cauveriensis, Oreichthys coorgensis, Mesonoemacheilus pambarensis, Hypselobarbus curmuca, and Pseudosphromenus cupanus to the Kabini Catchment.  The presence of four species, which were earlier considered to be endemic to the west flowing rivers of the Western Ghats, viz, Laubuka fasciata, Hypselobarbus kurali, Sahyadria denisonii, and Puntius mahecola, in an east flowing stream is reported and discussed.  Deforestation and removal of riparian vegetation, pollution, stream channel modification, sand mining, destructive fishing practices, dams and other impoundments, monsoon fishing, and non-native species are the major threats to freshwater fishes in the region.  Strategies for the conservation of aquatic ecosystems in the Kabini Catchment are discussed.

Invasion of a Headwater Stream by Non-Native Fishes in the Swartkops River System, South Africa

2011 ◽  
Vol 46 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Bruce R. Ellender ◽  
Olaf L.F. Weyl ◽  
Ernst R. Swartz
Keyword(s):  
South Africa ◽  
River System ◽  
Headwater Stream ◽  
Native Fishes

Chutes and ladders and other games we play with rivers. II. Simulated effects of translocation on white sturgeon

2006 ◽  
Vol 63 (1) ◽  
pp. 176-185 ◽  
Author(s):  
Henriette I Jager
Keyword(s):  
Fish Species ◽  
Simulation Study ◽  
River System ◽  
Genetic Effects ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
River Systems ◽  
Short Segment ◽  
River Fragmentation ◽  
Demographic Effects

Restoring connectivity is viewed as an important recovery option for fish species adversely affected by river fragmentation. This simulation study quantified the genetic and demographic effects of translocation on metapopulations of white sturgeon (Acipenser transmontanus) inhabiting a series of long (source) and short (sink) river segments. Genetic effects were predictable; upstream translocations increased introgression and downstream translocations had no effect. Demographic results suggest that indiscriminant efforts to reconnect populations may do more harm than good. Simulated river systems with high interspersion of long and short segments and a long segment far upstream tended to benefit most from translocation, but only when narrow screening or downstream passage was also provided below the river segment receiving fish. When combined with narrow screening, upstream translocation to a long segment subsidizing several downstream short segments produced the best results. Downstream passage outperformed narrow screening only when the translocation recipient was a short segment in a river system with low interspersion and no long, upstream river segment. This model-based evaluation of reconnection options has helped to refine ideas about restoring populations in fragmented rivers by predicting which options benefit riverine metapopulations as a whole.

scholarly journals Diversity of Bacteria and Fungi Associated with Freshwater Fishes from Mijawal River, Nasarawa, Nigeria

2020 ◽  
Vol 24 (6) ◽  
pp. 1085-2020
Author(s):  
K.M. Adamu ◽  
H. Muhammad ◽  
S.U. Ahmad ◽  
M.M. Ahmad ◽  
A.M. Yakubu
Keyword(s):  
Fish Species ◽  
Terrestrial Ecosystems ◽  
Freshwater Fishes ◽  
Frequency Of Occurrence ◽  
Salmonella Spp ◽  
Tilapia Zillii ◽  
Fish Samples ◽  
Bacteria And Fungi ◽  
Rhizopus Sp ◽  
Mormyrus Rume

Understudying the presence of bacteria and fungi population on freshwater fishes, provides the knowledge and understanding of their diversity and potential roles they may play in the health of the aquatic and terrestrial ecosystems. The present study was conducted to evaluate the diversity of bacteria and fungi species of identified fish samples from River Mijawal, Nasarawa State. The fishes were sampled from the only landing for three months (October to December, 2019) for this study. During the sampling periods, thirteen (13) different fish species were identified; they were  swabbed with sterilized swab stick from the skin surface for bacteria and fungi identification. The Dominant fish species were Tilapia zillii, Labeo senegalensis, Mormyrus rume and Mormyrus tapines. The total number of thirteen (13) bacterial and five (5) fungi species were isolated and  identified. Eight (8) of the bacteria isolates, were gram negative bacteria (Pseudomonas sp, Aeromonas sp, Serratia mercescenes, Proteus sp, Salmonella spp, Escherichia coli, Klebsiella sp, and Enterobacter sp.); whilst the other five (5) were gram positive bacteria (Bacillus sp, Micrococcus sp, Staphylococcus sp, Enterococcus sp and Listeria monocytogenes).The five isolated fungi species were Aspergillus niger, Rhizopus sp, Penicillium  sp, Trichoderma viridae and Geotrichum candidum. The frequency of occurrence of the isolated bacteria indicated that Staphylococcus sp had the highest frequency of occurrence (16.67%) while Serratia mercescens had the least occurrence (2.78%). The highest number of occurrence of the isolated fungi species was observed in Rhizopus sp while the least was recorded in Geotricum candidum. It was observed that Tilapia zillii and  Mormyrus rume had the most frequent bacteria and fungi isolates. It can therefore be deduced from the results that fish samples identified from River Mijawal has high bacteria and fungi diversity that may be pathogenic to man. The occurrence of these microbes may be attributed of human  and animal faeces in the River  Keywords: Freshwater fishes, Microbes, River Mijawal, Nasarawa  

scholarly journals The first unified inventory of non-native fishes of the South Caucasian countries, Armenia, Azerbaijan, and Georgia

2021 ◽  
pp. 32
Author(s):  
Tatia Kuljanishvili ◽  
Levan Mumladze ◽  
Bella Japoshvili ◽  
Namig Mustafayev ◽  
Shaig Ibrahimov ◽  
...  
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
Caspian Sea ◽  
Native Species ◽  
Biological Diversity ◽  
Native Fish ◽  
The Black Sea ◽  
The South ◽  
In The Wild ◽  
Native Fishes

The South Caucasus (SC) region is recognized for its high biological diversity and various endemic animal taxa. The area has experienced many fish introductions over the years, but the overall information about non-native fishes in the three SC countries, Armenia, Azerbaijan, and Georgia did not exist. Although these three countries belong to the Kura River drainage, Caspian Sea basin (only the western half of Georgia drains into the Black Sea), the legislative framework for each country regarding introduction of non-native fish species and their treatment is different and poorly developed. The goal of the present study was to make an initial inventory of non-native fish species in the three SC countries, and summarize the existing knowledge as a basis for future risk assessment models and formulation of regional management policies. Here, we present a unified list of 27 non-native species recorded in the wild in Armenia, Azerbaijan, and Georgia. Among these 27 species, eight were translocated from the Black Sea basin to the Caspian Sea basin. Out of these 27 non-native fishes, 15 species have become established (three of them being considered invasive) and six fish species could not survive in the wild.

scholarly journals A review of length-weight relationships of freshwater fishes in Malaysia

2018 ◽  
Vol 20 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Amonodin Mohamad Radhi ◽  
Mohd-Fadzil Nurul Fazlinda ◽  
Mohammad Noor Azmai Amal ◽  
Hashim Rohasliney
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Environmental Changes ◽  
Meta Analysis ◽  
Freshwater Fishes ◽  
Clarias Batrachus ◽  
Ecological Health ◽  
Allometric Growth ◽  
Freshwater Fish Species

Abstract This manuscript reviews the length-weight relationships (LWRs) of freshwater fishes in Malaysia. A total of 102 LWRs of fishes gathered from literature pertaining to 64 freshwater fish species were analysed. A meta-analysis from 13 previous reports showed that the b values was ranged from 2.19 (Clarias batrachus) to 4.106 (Barbodes binotatus). Out of 64 observed species, 47 species (11 families) experienced positive allometric growth, while another 23 species (eight families) and 31 species (12 families) were recorded under isometric and negative allometric growth, respectively. The fish LWRs observed can be used as an indicator of environmental changes and fish ecological health for freshwater fishes in Malaysia.

Development and validation of numerical habitat models for juveniles of Atlantic salmon (Salmo salar)

2000 ◽  
Vol 57 (10) ◽  
pp. 2065-2075 ◽  
Author(s):  
J C Guay ◽  
D Boisclair ◽  
D Rioux ◽  
M Leclerc ◽  
M Lapointe ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Depth ◽  
Current Speed ◽  
Fish Distribution ◽  
Biological Model ◽  
Habitat Models ◽  
Physical Conditions ◽  
Atlantic Salmon Salmo Salar

We evaluated the ability of numerical habitat models (NHM) to predict the distribution of juveniles of Atlantic salmon (Salmo salar) in a river. NHMs comprise a hydrodynamic model (to predict water depth and current speed for any given flow) and a biological model (to predict habitat quality for fish using water depth, current speed, and substrate composition). We implemented NHMs with a biological model based on (i) preference curves defined by the ratio of the use to the availability of physical conditions and (ii) a multivariate logistic regression that distinguished between the physical conditions used and avoided by fish. Preference curves provided a habitat suitability index (HSI) ranging from 0 to 1, and the logistic regression produced a habitat probabilistic index (HPI) representing the probability of observing a parr under given physical conditions. Pearson's correlation coefficients between HSI and local densities of parr ranged from 0.39 to 0.63 depending on flow. Corresponding values for HPI ranged from 0.81 to 0.98. We concluded that HPI may be a more powerful biological model than HSI for predicting local variations in fish density, forecasting fish distribution patterns, and performing summer habitat modelling for Atlantic salmon juveniles.

Historical Changes in Large River Fish Assemblages of the Americas

2005 ◽  
Keyword(s):  
Native Species ◽  
Fish Assemblages ◽  
Fish Fauna ◽  
River System ◽  
Endangered Species Act ◽  
Large River ◽  
Main Stem ◽  
Lake Mead ◽  
Virgin River ◽  
Native Fishes

<em>Abstract.</em>—The Virgin–Moapa River system supports nine native fish species or subspecies, of which five are endemic. Woundfin <em>Plagopterus argentissimus </em>and Virgin River chub <em>Gila seminuda </em>are endemic to the main-stem Virgin River, whereas cooler and clearer tributaries are home to the Virgin spinedace <em>Lepidomeda mollispinis</em>. Moapa dace <em>Moapa coriacea </em>and Moapa White River springfish <em>Crenichthys baileyi moapae </em>are found in thermal springs that form the Moapa River, and Moapa speckled dace <em>Rhinichthys osculus moapae </em>is generally found below the springs in cooler waters. The agricultural heritage of the Virgin–Moapa River system resulted in numerous diversions that increased as municipal demands rose in recent years. In the early 1900s, trout were introduced into some of the cooler tributary streams, adversely affecting Virgin spinedace and other native species. The creation of Lake Mead in 1935 inundated the lower 80 km of the Virgin River and the lower 8 km of the Moapa River. Shortly thereafter, nonnative fishes invaded upstream from Lake Mead, and these species have continued to proliferate. Growing communities continue to compete for Virgin River water. These anthropogenic changes have reduced distribution and abundance of the native Virgin–Moapa River system fish fauna. The woundfin, Virgin River chub, and Moapa dace are listed as endangered, and the Virgin spinedace has been proposed for listing. In this paper we document how the abundance of these species has declined since the Endangered Species Act of 1973. Currently, there is no strong main-stem refugium for the Virgin River native fishes, tributary refugia continue to be shortened, and the Moapa River native fishes continue to be jeopardized. Recovery efforts for the listed and other native fishes, especially in the Virgin River, have monitored the declines, but have not implemented recovery actions effective in reversing them.

Invasive Asian Carps in North America

2011 ◽  
Keyword(s):  
Fish Species ◽  
Mississippi River ◽  
Grass Carp ◽  
Trophic Position ◽  
River System ◽  
Ctenopharyngodon Idella ◽  
Ecological Effect ◽  
Small Samples ◽  
Black Carp ◽  
Asian Carps

<em>Abstract</em>.—The black carp <em>Mylopharyngodon piceus </em>is a large (>1 m long) riverine fish from eastern Asia introduced into the United States via the aquaculture industry. A wild population has been present in the lower Mississippi River basin since the early 1990s, but little is known about the ecological effect of black carp in invaded environments. In its native range, black carp feed almost exclusively on mollusks. In U.S. waters, they likely prey on native mussels, but few wild-caught specimens have been examined by biologists and all have had empty gastrointestinal tracts. In lieu of stomach content data, we examined isotopic values (δ<sup>13</sup>C and δ <sup>15</sup>N) and mercury (Hg) concentrations in muscle tissue of black carp and 10 other large nonnative and native fish species captured in the Red–Atchafalaya River system of Louisiana, USA. Trophic position estimates derived from δ <sup>15</sup>N values ranged from 2.0 for grass carp <em>Ctenopharyngodon idella </em>to 4.8 for blue catfish <em>Ictalurus furcatus </em>and flathead catfish <em>Pylodictis olivaris</em>. Adult black carp had a δ <sup>15</sup>N value (13.2‰), indicating a trophic level of 3.5. Mean total Hg concentrations ranged from 0.02 µg/g in grass carp to 0.27 µg/g in bigmouth buffalo <em>Ictiobus cyprinellus</em>, in black carp 0.17 µg/g; Hg increased with increasing δ <sup>15</sup>N, indicating biomagnification. The limited numbers of taxa and small samples sizes, as well as constraints in methods used, do not allow confirmation that wild black carp are consuming native mollusks. However, our stable isotope results do provide evidence that its diet is similar to other large fish species inhabiting the Red–Atchafalaya system considered to be benthic invertivores, including some known to prey on freshwater mollusks (i.e., smallmouth buffalo <em>I. bubalus </em>and nonnative common carp <em>Cyprinus carpio</em>).

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