Proposed Standard Length–Weight Equation for Northern Pike

AbstractWe conducted a snapshot study to check the importance of non-native Ponto-Caspian gobies (monkey and racer goby) in the diet of native obligate (northern pike, pikeperch) and facultative (Eurasian perch) predators in the Vistula River 3–4 years after the appearance of aliens. In total 71 fish with non-empty stomachs, taken randomly from net catches from various parts of the river were analyzed, including 32 pike, 20 pikeperch and 19 perch specimens. We found that gobiids prevailed in the diet of smaller (<30 cm standard length, SL) individuals of pike and pikeperch, as well as larger (>15 cm SL) specimens of perch, although the effect of predator size on the presence of gobiids in the diet was not significant in the case of perch. Our results indicate that gobiids as a prey fish can stimulate considerable changes in local food webs, which require further studies.

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Feeding Flexibility in Northern Pike (Esox lucius): Fish versus Invertebrate Prey

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-085 ◽

1989 ◽

Vol 46 (4) ◽

pp. 666-669 ◽

Cited By ~ 37

Author(s):

Lauren J. Chapman ◽

William C. Mackay ◽

Craig W. Wilkinson

Keyword(s):

Northwest Territories ◽

Standard Length ◽

Stomach Contents ◽

Northern Pike ◽

Esox Lucius ◽

Frequency Of Occurrence ◽

Pike Esox Lucius ◽

Invertebrate Prey ◽

Seasonal Basis

We describe the frequency of occurrence of fish and invertebrates in the stomach contents of northern pike (Esox lucius) from eight populations in Alberta and the Northwest Territories. Lakes were sampled one to eight times between 1979 and 1985, and a total of 899 pike were examined (mean standard length = 44 ± 8 cm, SD). Although northern pike are widely considered to be top aquatic piscivores, we found that the frequency of occurrence of invertebrates was high, at least on a seasonal basis, in some systems. In all of the lakes considered, the frequency of occurrence of fish (expressed as a percentage of non-empty stomachs) was 88% or greater in one or more of the sample periods. However, diets where the frequency of occurrence of invertebrates was greater than 90% occurred in three of the populations in one or more of the sample periods. The frequency of occurrence of invertebrates was negatively correlated with the percentage of empty stomachs, while the frequency of occurrence of fish was positively related to the percentage of empty stomachs. Invertebrate feeding was not limited exclusively to smaller pike; invertebrates were found in the stomachs of pike 24 to 60 cm long (standard length).

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Complete sequences of 4 viral hemorrhagic septicemia virus IVb isolates and their virulence in northern pike fry

Diseases of Aquatic Organisms ◽

10.3354/dao03171 ◽

2017 ◽

Vol 126 (3) ◽

pp. 211-227 ◽

Cited By ~ 7

Author(s):

RG Getchell ◽

ER Cornwell ◽

S Bogdanowicz ◽

J Andrés ◽

WN Batts ◽

...

Keyword(s):

Northern Pike ◽

Viral Hemorrhagic Septicemia Virus ◽

Viral Hemorrhagic Septicemia ◽

Complete Sequences

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Occurrence of Various Off-Flavours in Fish in Finland from 1969 to 1981

Water Science & Technology ◽

10.2166/wst.1983.0129 ◽

1983 ◽

Vol 15 (6-7) ◽

pp. 47-58 ◽

Cited By ~ 3

Author(s):

T Kuusi ◽

M Suihko

Keyword(s):

Research Laboratory ◽

Kraft Pulp ◽

Pulp Mill ◽

Northern Pike ◽

Research Centre ◽

Pulp Mill Effluent ◽

Technical Research ◽

Kraft Pulp Mill ◽

Food Research ◽

Numerical Scale

Off-flavours in fish were studied from 1969 to 1981 at the Food Research Laboratory of the Technical Research Centre of Finland using sensory methods. In all, 1982 samples of 18 species of Finnish fish, most of them suspected of being tainted, were studied. A trained taste panel scoring on a numerical scale of 0-10, where a score of 5 or less was unacceptable, was used. The off-flavours described were oil, kraft pulp mill effluent, sewage (musty), muddy, rancid, and others. Of all these samples, 34.9% were unacceptable. The most common off-flavour was kraft pulp mill effluent, present in 41.2 % of the unacceptable samples. In acceptable fish slight off-flavours were somet imes found. Of the muddy fish, only 35.2 % of the bream and 28.8 % of the northern pike were unacceptable. The panel was able to discriminate between the different off-flavours, but, in some cases, the boundaries were vague.

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Effect of early intervention for anxiety on sleep outcomes in adolescents: a randomized trial

European Child & Adolescent Psychiatry ◽

10.1007/s00787-021-01795-6 ◽

2021 ◽

Author(s):

Bente Storm Mowatt Haugland ◽

Mari Hysing ◽

Asle Hoffart ◽

Åshild Tellefsen Haaland ◽

Jon Fauskanger Bjaastad ◽

...

Keyword(s):

Early Intervention ◽

Standard Length ◽

Sleep Problems ◽

Sleep Onset ◽

Cognitive Behavioral ◽

Control Group ◽

Sleep Onset Latency ◽

Post Intervention ◽

Clinical Trial Registration

AbstractThe potential effect of early intervention for anxiety on sleep outcomes was examined in a sample of adolescents with anxiety (N = 313, mean 14.0 years, SD = 0.84, 84% girls, 95.7% Norwegians). Participants were randomized to one of three conditions: a brief or a standard-length cognitive-behavioral group-intervention (GCBT), or a waitlist control-group (WL). Interventions were delivered at schools, during school hours. Adolescents with elevated anxiety were recruited by school health services. Questionnaires on self-reported anxiety symptoms, depressive symptoms, and sleep characteristics were administered at pre- and post-intervention, post-waitlist, and at 1-year follow-up. Adolescents reported reduced insomnia (odds ratio (OR) = 0.42, p < 0.001) and shorter sleep onset latency (d = 0.27, p < 0.001) from pre- to post-intervention. For insomnia, this effect was maintained at 1-year follow-up (OR = 0.54, p = 0.020). However, no effect of GCBT on sleep outcomes was found when comparing GCBT and WL. Also, no difference was found in sleep outcomes between brief and standard-length interventions. Adolescents defined as responders (i.e., having improved much or very much on anxiety after GCBT), did not differ from non-responders regarding sleep outcomes. Thus, anxiety-focused CBT, delivered in groups, showed no effect on sleep outcomes. Strategies specifically targeting sleep problems in adolescents should be included in GCBT when delivered as early intervention for adolescents with elevated anxiety.Trial registry Clinical trial registration: School Based Low-intensity Cognitive Behavioral Intervention for Anxious Youth (LIST); http://clinicalrials.gov/; NCT02279251, Date: 11.31. 2014

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