Effects of brown trout, Salmo trutta L., on the distribution of some native fishes in three areas of southern Victoria

1980 ◽  
Vol 31 (1) ◽  
pp. 61 ◽  
Author(s):  
PD Jackson ◽  
WD Williams

Eight species of native fish and two of introduced fish were found during studies of the distribution of fishes in streams in three areas of southern Victoria; namely in the upper part of the catchment of the Yarra River, in the Otway Ranges, and on Wilsons Promontory. S. trutta does not occur on Wilsons Promontory, but does occur in the other two areas. Results provide circumstantial evidence that S. trutta has deleteriously affected the occurrence of Galaxias olidus and possibly G. brevipinnis. Some native fishes appear able to coexist with S. trutta.

Biologia ◽  
2016 ◽  
Vol 71 (6) ◽  
Author(s):  
Rocco Tiberti ◽  
Emiliano Mori

AbstractIntroduced fish represent a major threat for aquatic ecosystems and species and their impact on semiaquatic vertebrates, such as amphibians, has been extensively studied. On the other hand, little is known about their impact on semiaquatic mammals, such as water shrews (


2021 ◽  
Vol 24 (2) ◽  
pp. 33-42
Author(s):  
Aashna Sharma ◽  
Vineet Kumar Dubey ◽  
Jeyaraj Antony Johnson ◽  
Yogesh Kumar Rawal ◽  
Kuppusamy Sivakumar

Abstract Often regarded as a potential threat to the native fish fauna worldwide, the Brown Trout (Salmo trutta), has successfully established its population in the majority of the Himalayan rivers post its introduction dating back to the eighteenth century. Over the years, the species has gained infamy as a sport fish and is considered a profitable source of income to the locals ensuing a heightened propagule pressure due to lack of appropriate management actions. No comprehensive study has been conducted to date in order to understand the mechanism by which the Brown Trout poses threat to the native fish populations. Through the present study, we could assess its competition with the native Snow Trout (Schizothorax richardsonii) to understand the spatial assemblage of both the species across space in Tirthan, a pristine high-altitude river of the western Himalaya. River Tirthan is one of the major tributaries of River Beas traversing for most of its stretch within the protected boundaries of the Great Himalayan National Park Conservation Area. A total of 108 sampling points were chosen from confluence to origin of rivers/streams, ranging from 989 to 3677msl. A total of 28 explanatory variables were recorded at each point. Overall, the Brown Trout adults were found to be greater in relative abundance (66.1%) than the Snow Trout adults (33.9%). The fingerlings of Snow Trout on the other hand, were distinctively high in relative abundance (61.9%) than those of the invasive Brown Trout (38.1%). Non-native trout showed higher abundance in the higher stream orders i.e. in the main streams while natives mostly restricted themselves to the lower order streams. Redundancy analysis (RDA) for species and environmental covariates resulted in 40.75% of constrained variance with higher eigen values for Redundancy analysis1 and Redundancy analysis2. Ward’s minimum variance clustering of Hellinger transformed data revealed sites agglomerating into six reasonable distinct subgroups with respect to species abundances. Immature individuals of non-native and native trout used similar habitat conditions, but they differed in using habitats at adult stage. Our results show a competitive dominance of Brown Trout in terms of higher abundance and maximum space utilization that highlight an urgent action for preventing its introductions to new areas. We recommend a national policy of ‘The Indian Invasive Species Act’ and management level interventions to control overstocking in the areas of established population.


1995 ◽  
Vol 52 (10) ◽  
pp. 2159-2167 ◽  
Author(s):  
T. Hesthagen ◽  
O. Hegge ◽  
J. Skurdal ◽  
B. K. Dervo

Native and native-stocked brown trout (Salmo trutta) in Lake Tesse, a regulated hydroelectric reservoir (southern Norway), were spatially segregated according to size: small individuals occurred mainly in the epibenthic habitat and larger individuals mainly in the pelagic habitat. In contrast, all size groups of non-native stocked brown trout were mostly restricted to the epibenthic habitat. Age-specific lengths were generally larger for non-native than for native stocked trout, which were larger than native fish. However, growth rate between age 3 and 4 was significantly lower for non-native stocked fish than for native and native stocked fish. Differences in body length were mainly due to strain but also to some extent to habitat. Native fish had significantly fuller stomachs in the pelagic than in the epibenthic habitat in summer. Epibenthic non-native fish had significantly fuller stomachs than native and native stocked fish in August but not in July. Native and native stocked fish fed mainly on surface insects and planktonic crustaceans in both habitats. We hypothesize that the non-native brown trout stocked in Lake Tesse do not use the pelagic habitat in the home lake and are therefore less adapted to utilize such habitat than populations originating from lakes where pelagic habitat is available.


1969 ◽  
Vol 26 (8) ◽  
pp. 2165-2171 ◽  
Author(s):  
I. Chaston

In laboratory tests, brown trout were most active between dusk and dawn from spring to autumn, but the percentage of the total activity that occurred during daylight was higher in the summer than in the other two seasons. Analysis of the variation in the weight of stomach contents during 24 hr in the three seasons showed a higher peak in weight at noon in summer than in the other seasons. The difference was related to an increased consumption of material of terrestrial origin, which other work showed to be most available to the fish between 09.00 and 12.00 hr. No relationship was found between the times of maximum occurrence of benthic and emergent items in the stream and of their consumption by trout. The increase in daytime activity during the summer was also evidently related to increased consumption of terrestrial material.


2011 ◽  
Vol 14 (3) ◽  
pp. 443-448 ◽  
Author(s):  
N. Kurhalyuk ◽  
H. Tkachenko ◽  
K. Pałczyńska

Resistance of erythrocytes from Brown trout (Salmo trutta m. trutta L.) affected by ulcerative dermal necrosis syndrome In the present work we evaluated the effect of ulcerative dermal necrosis (UDN) syndrome on resistance of erythrocytes to haemolytic agents and lipid peroxidation level in the blood from brown trout (Salmo trutta m. trutta L.). Results showed that lipid peroxidation increased in erythrocytes, as evidenced by high thiobarbituric acid reactive substance (TBARS) levels. Compared to control group, the resistance of erythrocytes to haemolytic agents was significantly lower in UDN-positive fish. Besides, UDN increased the percent of hemolysated erythrocytes subjected to the hydrochloric acid, urea and hydrogen peroxide. Results showed that UDN led to an oxidative stress in erythrocytes able to induce enhanced lipid peroxidation level, as suggested by TBARS level and decrease of erythrocytes resistance to haemolytic agents.


2021 ◽  
Vol 29 ◽  
pp. 100675
Author(s):  
Muhammed Atamanalp ◽  
Arzu Ucar ◽  
Esat Mahmut Kocaman ◽  
Gonca Alak

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