The conservation of freshwater fishes in the British isles

The study has been carried in the year 2004 and describes fecundity, spawning season and sex ratio of brown trout, Salmo trutta fario. A total of 121 brown trout (67 males and 54 females) were captured by angling. Gonad somatic index (GSI) confirmed that spawning lasted from October to December. The left ovary, with some exceptions, was found to be longer and heavier producing more eggs than the right one. The absolute fecundity of sampled population varied from 527 to 2445 and the relative fecundity had a mean value of 2.56. Fecundity was positively co-related with the total fish length (r=0.865), fish weight (r=0.9426) ovary weight (r=0.952) and ovary length (r=0.845).

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“…Maitland and Campbell (1992) mentioned that the number of males in migrating trout populations were more abundant then females.…”

Section: Journal Of Biology and Life Sciencementioning

confidence: 99%

Study on the fecundity of Salmo trutta fario (Brown trout) in Kashmir

Rasool

Jan

2012

JBLS

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“…Fishes used in the experiment below were size matched as closely as possible with respect to total length (TL) and gape height (GH) (TL cm ± S.E., goby = 8.6 ± 0.22, bullhead = 8.0 ± 0.17, GH mm ± S.E., goby = 6.16 ± 0.25, bullhead = 6.25 ± 0.19); these measurements were derived from the same individuals used in experiments. This balanced (1) the use of comparable body sizes of the two fish species to examine species-effects on feeding rates with minimal confounds of body size, but (2) was also a very conservative body size (and hence gape size and gut capacity) of the invader, which in the wild attains much greater size than the native (Fuller et al 2007;Maitland and Campbell 1992).…”

Section: Introductionmentioning

confidence: 99%

Assessing the ecological impacts of invasive species based on their functional responses and abundances

Laverty

Green

Dick³

et al. 2017

Biol Invasions

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Invasive species management requires allocation of limited resources towards the proactive mitigation of those species that could elicit the highest ecological impacts. However, we lack predictive capacity with respect to the identities and degree of ecological impacts of invasive species. Here, we combine the relative per capita effects and relative field abundances of invader as compared to native species into a new metric, ''Relative Impact Potential'' (RIP), and test whether this metric can reliably predict high impact invaders. This metric tests the impact of invaders relative to the baseline impacts of natives on the broader ecological community. We first derived the functional responses (i.e. per capita effects) of two ecologically damaging invasive fish species in Europe, the Ponto-Caspian round goby (Neogobius melanostomus) and Asian topmouth gudgeon (Pseudorasbora parva), and their native trophic analogues, the bullhead (Cottus gobio; also C. bairdi) and bitterling (Rhodeus amarus), towards several prey species. This establishes the existence and relative strengths of the predator-prey relationships. Then, we derived ecologically comparable field abundance estimates of the invader and native fish from surveys and literature. This establishes the multipliers for the above per capita effects. Despite both predators having known 123Biol Invasions (2017) 19:1653-1665 DOI 10.1007/s10530-017-1378 severe detrimental field impacts, their functional responses alone were of modest predictive power in this regard; however, incorporation of their abundances relative to natives into the RIP metric gave high predictive power. We present invader/native RIP biplots that provide an intuitive visualisation of comparisons among the invasive and native species, reflecting the known broad ecological impacts of the invaders. Thus, we provide a mechanistic understanding of invasive species impacts and a predictive tool for use by practitioners, for example, in risk assessments.

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“…Larger chub specimens also eat different species of small fish (Maitland and Campbell 1992). The chubs were caught in the Sava River in Croatia.…”

Section: Fish Samplingmentioning

confidence: 99%

Multielement analysis in the fish hepatic cytosol as a screening tool in the monitoring of natural waters

Dragun

Fiket

Vuković

et al. 2012

Environ Monit Assess

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The possibility of direct measurement of trace elements in hepatic cytosol of European chub (Squalius cephalus) by HR ICP-MS after cytosol dilution with Milli-Q water and subsequent acidification was investigated. Due to low detection limits of this procedure, determination of 13 elements (As, Cd, Co, Cu, Fe, Mn, Mo, Pb, Sb, Sn, Sr, V, Zn) was possible in the chub hepatic cytosol, exhibiting excellent measurement repeatability in duplicates. Some of these elements were also measured by HR ICP-MS in acid digested cytosols (Cd, Co, Cu, Fe, Mn, Mo, Sr, V, Zn). Good agreement of the results obtained after sample dilution and sample digestion indicated that complex organic matrix of hepatic cytosol did not affect measurement reliability. Cytosolic concentrations of 13 trace elements in the chub liver were quantified in the following order:Fe,Zn>Cu>Mn>Mo>Sr,V,Cd>Co>As,Pb>Sn>Sb. Unlike Cd, Cu, Fe, Mn and Zn for which the cytosolic concentrations were previously reported after measurement by AAS, cytosolic concentrations of eight additional trace elements characteristic for the liver of chubs inhabiting the low contaminated river water were reported here for the first time (ng g -1 ): Mo 136. and Sb 0.9-2.6. The simultaneous measurement of large number of trace elements in the cytosolic fractions of fish tissues, which comprise potentially metal-sensitive sub-cellular pools, could be beneficial as a screening tool in the monitoring of natural waters, because it would enable timely recognition of increased fish exposure to metals.

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The conservation of freshwater fishes in the British isles

Cited by 67 publications

References 8 publications

Study on the fecundity of Salmo trutta fario (Brown trout) in Kashmir

Study on the fecundity of Salmo trutta fario (Brown trout) in Kashmir

Assessing the ecological impacts of invasive species based on their functional responses and abundances

Multielement analysis in the fish hepatic cytosol as a screening tool in the monitoring of natural waters

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