Relationship between Diurnal Activity Patterns, Cryptic Coloration, and Subsequent Avoidance of Predaceous Fish by Perlid Stoneflies

1992 ◽  
Vol 49 (12) ◽  
pp. 2630-2634 ◽  
Author(s):  
Blair W. Feltmate ◽  
D. Dudley Williams ◽  
Adriane Montgomerie
Keyword(s):  
Rainbow Trout ◽  
Activity Patterns ◽  
Diurnal Activity ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Daytime Activity ◽  
Cryptic Coloration ◽  
High Illumination ◽  
Low Illumination ◽  
Paragnetina Media ◽  
First Time

We demonstrate that prey (stoneflies), which are either solidly coloured or patterned, coordinate intervals of maximum daytime activity with periods when visually foraging predators (rainbow trout, Oncorhynchus mykiss) are least able to detect them. In this study, rainbow trout attacked solidly coloured stonefly nymphs (Paragnetina media) more frequently under conditions of low illumination (simulated dawn and dusk) than high illumination (simulated midday) whereas the frequency of attacks on patterned stonefly nymphs (Agnetina capitata) was reversed. Consequently, in both the presence and absence of trout, the activity (i.e. frequency of crawling) of P. media and A. capitata was highest under conditions of high and low illumination, respectively. The number of attacks by trout on all nymphs was significantly less when nymphs were on dark-brown, rather than mottled, substrates. When given a choice between dark-brown and mottled substrate, both species selected dark substrate. Suggestions that the visual acuity of predators varies as a function of light intensity and the coloration, patterning, and daytime activity of prey are corroborated for the first time.

scholarly journals First record of Schulmanela petruschewskii Shulman, 1948 (Nematoda: Capillariidae) from cultured Rainbow trout (Oncorhynchus mykiss) in Turkey

2010 ◽  
Vol 47 (4) ◽  
pp. 273-275
Author(s):  
Z. Pekmezci ◽  
S. Umur
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
New Record ◽  
Parasite Species ◽  
Liver Parenchyma ◽  
First Record ◽  
Parasite Fauna ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
First Time ◽  
North Latitude

AbstractThe nematode Schulmanela petruschewskii (Shulman, 1948) was identified during the parasitological examination on the liver parenchyma in one specimens of a cultured rainbow trout (Oncorhynchus mykiss) which reared in Derbent Dam Lake in Samsun, Turkey (41°25′6′’ North latitude, 35°49′52′’ East longitude) in August 2008. This parasite species was not previously reported from Turkey. With the present study we report S. petruschewskii for the first time in Turkey. This specimen which is a parasite of cultured rainbow trout (Oncorhynchus mykiss) is a new record for the Turkish parasite fauna. Original measurements and figures are presented.

Myotomal slow muscle function of rainbow trout Oncorhynchus mykiss during steady swimming.

1998 ◽  
Vol 201 (10) ◽  
pp. 1659-1671 ◽  
Author(s):  
L Hammond ◽  
J D Altringham ◽  
C S Wardle
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Body Length ◽  
Muscle Activation ◽  
Activity Patterns ◽  
The Body ◽  
Entire Body ◽  
Negative Power ◽  
Rainbow Trout Oncorhynchus Mykiss

Strain and activity patterns were determined during slow steady swimming (tailbeat frequency 1.5-2.5 Hz) at three locations on the body in the slow myotomal muscle of rainbow trout Oncorhynchus mykiss using sonomicrometry and electromyography. Strain was independent of tailbeat frequency over the range studied and increased significantly from +/-3.3 % l0 at 0.35BL to +/-6 % at 0.65BL, where l0 is muscle resting length and BL is total body length. Muscle activation occurred significantly later in the strain cycle at 0.35BL (phase shift 59 degrees) than at 0.65BL (30 degrees), and the duration of activity was significantly longer (211 degrees at 0.35BL and 181 degrees at 0.65BL). These results differ from those of previous studies. The results have been used to simulate in vivo activity in isolated muscle preparations using the work loop technique. Preparations from all three locations generated net positive power under in vivo conditions, but the negative power component increased from head to tail. Both kinematically, and in the way its muscle functions to generate hydrodynamic thrust, the rainbow trout appears to be intermediate between anguilliform swimmers such as the eel, which generate thrust along their entire body length, and carangiform fish (e.g. saithe Pollachius virens), which generate thrust primarily at the tail blade.

Diurnal and nocturnal feeding activity in Arctic char (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 54 (12) ◽  
pp. 2894-2900 ◽  
Author(s):  
Anders Alanärä ◽  
Eva Brännäs
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Salvelinus Alpinus ◽  
Feeding Activity ◽  
Activity Patterns ◽  
Arctic Char ◽  
Diel Activity ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Nocturnal Feeding ◽  
Nocturnal Fish

When food is limited and competition for it is high, individual fish may adopt different diel activity patterns. We followed individual feeding activity in groups of 10 Arctic char (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss) using a combined self-feeding and PIT-tag system. Food was supplied at low and high rewards to five replicate groups of Arctic char and rainbow trout. Four categories were identified in both species: high-triggering diurnal (diurnal fish with the highest self-feeding activity), low-triggering diurnal, nocturnal, and nontriggering fish. On average, the photophase proportion of the total daily activity was approx 90% in diurnal and approx 20% in nocturnal individuals. Rainbow trout offered high rewards did not show any diel preferences. Diurnal Arctic char and rainbow trout with the highest self-feeding activity were initially larger and had the highest growth rates, indicating a high social position. Nocturnal fish were initially smaller and their proportion of trigger actuations much lower than the high-triggering diurnal fish. These still grew successfully whereas nontriggering fish grew significantly less. Thus, some individuals with a low social status may apply an alternative strategy to attain adequate growth by feeding at night when dominant individuals are less aggressive. This may be referred to as concurrent dualism (diurnalism and nocturnalism).

Influence of Rainbow Trout (Oncothynchus mykiss) on Density and Feeding Behaviour of a Perlid Stonefly

1989 ◽  
Vol 46 (9) ◽  
pp. 1575-1580 ◽  
Author(s):  
Blair W. Feltmate ◽  
D. Dudley Williams
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Feeding Behaviour ◽  
Predator Avoidance ◽  
Feeding Rate ◽  
Avoidance Behaviour ◽  
Substrate Selection ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Paragnetina Media

Stonefly (Paragnetina media) density was reduced in a rainbow trout (Oncorhynchus mykiss) enclosure by approximately 35%, whereas in a trout exclosure no significant changes in density occurred. Of the 35% reduction, approximately two-fifths and three-fifths were attributable, respectively to direct consumption of stoneflies by trout, and emigration by stoneflies from the predator-stressed section of stream. With trout present in laboratory aquaria, predator avoidance behaviour resulted in stoneflies remaining significantly more on dark substrate on which they were less vulnerable to trout predators. Stoneflies consumed significantly fewer prey (enchytraeid whiteworms) over 24 h, in the presence of both small (2.0–4.0 cm) and large (10.0–12.0 cm) rainbow trout in aquaria, compared with stoneflies feeding in trout-free aquaria. Feeding rate and substrate selection did not differ between well-fed and starved (5 d) nymphs.

scholarly journals beta-Naphthoflavone abolishes interrenal sensitivity to ACTH stimulation in rainbow trout

1998 ◽  
Vol 157 (1) ◽  
pp. 63-70 ◽  
Author(s):  
JM Wilson ◽  
MM Vijayan ◽  
CJ Kennedy ◽  
GK Iwama ◽  
TW Moon
Keyword(s):  
Cytochrome P450 ◽  
Rainbow Trout ◽  
Acth Stimulation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Treated Fish ◽  
First Time ◽  
Hepatic Cytochrome ◽  
Stimulation Of

We report for the first time that beta-naphthoflavone (BNF) abolishes ACTH stimulation of cortisol production in rainbow trout (Oncorhynchus mykiss). There was significantly higher hepatic cytochrome P450 content and ethoxyresorufin O-de-ethylase and uridine-5'-diphosphoglucuronic acid transferase activities in BNF-treated fish than in sham-treated controls. BNF did not significantly affect either plasma turnover or tissue distribution of [3H]cortisol-derived radioactivity. Hepatic membrane fluidity and hepatocyte capacity for cortisol uptake were not altered by BNF as compared with the sham-treated fish. These results taken together suggest that BNF does not affect cortisol-clearance mechanisms in trout. A 3 min handling disturbance period elicited a plasma cortisol response in the sham-treated fish; however, the response in the BNF-treated fish was muted and significantly lower than in the sham fish. This in vivo response corroborates the lack of interrenal sensitivity to ACTH in vitro in the BNF-treated fish, suggesting that BNF affects the ACTH pathway in trout. Our results suggest the possibility that cytochrome P450-inducing compounds may affect cortisol dynamics by decreasing interrenal responsiveness to ACTH stimulation in fish, thereby impairing the physiological responses that are necessary for the animal to cope with the stressor.

Correlations between pituitary and testis in sexually maturing male rainbow trout, Oncorhynchus mykiss, during spermatogenesis

1990 ◽  
Vol 68 (4) ◽  
pp. 678-683 ◽  
Author(s):  
Sylvia M. Ruby ◽  
Simon Bryant
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Significant Role ◽  
Cyst Formation ◽  
Histological Changes ◽  
Histological Evidence ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Apparent Correlation ◽  
Specific Stage ◽  
First Time

Histological changes in the pituitary of sexually maturing male rainbow trout, Oncorhynchus mykiss, were correlated with spermatogenesis in the testes. Granular basophils in the pituitary appeared simultaneously with the development of spermatogonial cysts in the testis. There was no histological evidence that basophils released their granules during spermatogonial cyst formation. A coefficient of correlation was calculated to test the interaction between the numbers of granular basophils and cysts of spermatogonia. The correlation was not significant. These findings suggest that granules from pituitary basophils do not play a significant role in the development of spermatogonial cysts. Histological sections revealed that basophils degranulated rapidly with the appearance of cysts of spermatocytes. A significant correlation (r = −96) between basophils and cysts of spermatocytes occurred when the interaction between these two variables was tested. The negative correlation indicated that pituitary basophils decreased in number as cysts of spermatocytes in the testes increased. These findings provide support for the hypothesis that basophils may play a significant role in the development of spermatocyte cysts in rainbow trout testes. A second nongranular basophil observed in the pituitaries of fish in this study had no apparent correlation with any of the stages of spermatogenesis. While previous investigators have reported the appearance of granular basophils in the pituitary concurrent with the process of spermatogenesis, this marks the first study that compares histological changes in the testis directly with those in the pituitary in sexually maturing rainbow trout. In addition, it reports for the first time a significant correlation between basophils and a specific stage in the cycle of spermatogenesis.

Redefining the activity pattern of the honey possum (Tarsipes rostratus).

2001 ◽  
Vol 23 (2) ◽  
pp. 169 ◽  
Author(s):  
C Arrese ◽  
PB Runham
Keyword(s):  
Activity Pattern ◽  
Activity Patterns ◽  
Diurnal Activity ◽  
Numerous Species ◽  
Daytime Activity ◽  
In Captivity ◽  
In The Wild ◽  
Australian Marsupial ◽  
Diurnal Species ◽  
Honey Possum

ANIMALS are commonly separated into two major categories based on their activity patterns: diurnal and nocturnal. However, evidence of numerous species exhibiting diverse periods of activity, including arhythmic and crepuscular habits, broadens the description. The honey possum (Tarsipes rostratus), a small West-Australian marsupial feeding exclusively on nectar and pollen, has been described as strongly nocturnal (Wooller et al. 1981; Russell and Renfree 1989). However, infrequent daytime activity in captivity (Russell 1986) and in the wild under cold, cloudy conditions, has been reported (Hopper and Burbidge 1982; du Plessis and du Plessis 1995). During trapping exercises in the region of Jurien Bay (250 km north of Perth, Western Australia), several animals were observed foraging after sunrise and before sunset, with occasional diurnal activity. To date, no study has investigated directly the activity periods of the species. Furthermore, studies of the visual capabilities of T. rostratus revealed that its retinal organisation is not compatible with a nocturnal lifestyle, but presents features comparable to those found in diurnal species (Arrese 2002; Arrese et al. 2002). Such discrepancies warranted the monitoring of activity periods (rhythmicity) of T. rostratus in its natural environment, a study reported here. We discuss our results in the context of the visual ecology of the species.

scholarly journals Transgenic rainbow trout expressed sGnRH-antisense RNA under the control of sGnRH promoter of Atlantic salmon

2000 ◽  
Vol 25 (3) ◽  
pp. 337-350 ◽  
Author(s):  
S Uzbekova ◽  
J Chyb ◽  
F Ferriere ◽  
T Bailhache ◽  
P Prunet ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Transgenic Fish ◽  
Transgenic Animals ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Males And Females ◽  
Mature Fish ◽  
First Time ◽  
The Brain ◽  
F2 Progeny

A recombinant vector containing antisense DNA complementary to Atlantic salmon (Salmo salar) sGnRH cDNA driven by specific promoter Pab derived from a corresponding sGnRH gene was introduced into rainbow trout (Oncorhynchus mykiss) eggs. This resulted in transgenic animals that had integrated one copy of the transgene into their genome and transmitted it through the germline. Antisense-sGnRH mRNA (AS) was expressed mainly in the brain of transgenic AS(+) fish. Levels of sGnRH endogenous mRNA in the brain were lower in 11-month-old AS(+) fish compared with nontransgenic AS(-) individuals from the same F2 progeny. sGnRH levels significantly decreased in the pituitary of transgenic males and females around the maturation period and in the brain of AS(+) immature females compared with controls. No reliable statistical difference was found in the levels of FSH and LH between AS(+) and AS(-) groups either in immature or mature fish. The majority of transgenic fish reached maturity at the same time as did nontransgenic individuals, although the maturation of AS(+) animals seemed to be more asynchronous. For the first time, the influence of antisense messengers on endogenous mRNA in transgenic fish and the corresponding protein is described.

scholarly journals PECULIARITIES OF CULTIVATION OF THE ORANGE-FIN RAINBOW TROUT ONCORHYNCHUS MYKISS (WALBAUM, 1792) IN CONDITIONS OF THE SULAK CANYON

2019 ◽  
pp. 14-19
Author(s):  
Evgeny Nikolaevich Lobachev ◽  
Ruslan Magomedovich Barkhalov ◽  
Nukhkadi Ibragimovich Rabazanov ◽  
Umshanat Dzhamaldinovna Zurkhaeva
Keyword(s):  
Rainbow Trout ◽  
Average Weight ◽  
Commercial Fish ◽  
Spring Period ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Weight Growth ◽  
The Republic ◽  
First Time ◽  
Feed Coefficient

The article has, for the first time in 20 years, presented the data on weight growth of the rainbow trout, grown in cag-es, in the territory of the Republic of Daghestan. The experiment has been conducted on the 5000 fries of the rainbow trout with an average weight of 41 gr. throughout the spring period. Tested was the original feed of the simplified rec-ipes and the minimal equipment costs for its production. As a result, it was proved that in the territory of the Sulak canyon there are all opportunities for growing commercial fish in cages. The results of the study showed that by the end of the experiment, the average weight of rainbow trout fry had reached 80 gr., the feed coefficient was 0,57–0,60%, while the loss of the fry was not observed. That indicates good quality of the food and favorable natural conditions for growing fish.

scholarly journals Diseases of different aetiologies in salmonids in Ukraine

Biologija ◽  
2020 ◽  
Vol 65 (4) ◽  
Author(s):  
Nаtalia Matvienko ◽  
Maria Maistrenko ◽  
Leonid Buchatsky ◽  
Alexander Didenko
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Fish Farms ◽  
Thymallus Thymallus ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Brown Trout Salmo Trutta ◽  
European Genotype ◽  
First Time ◽  
Natural Water Bodies

The paper contains the results of the studies into the ichthyopathological situation of the invasion and infectious diseases of salmonids carried out by the Ichthyopathology Laboratory of the Institute of Fisheries of Ukraine from 2013 to 2016. The investigated salmonid species included: the rainbow trout Oncorhynchus mykiss, the brown trout Salmo trutta morpha fario, the brook trout Salvelinus fontinalis, and the European grayling Thymallus thymallus. The fish were sampled from aquatculture farms as well as natural water bodies and their diseases included invasive (parasitic) and infectious (viral and bacterial). The most frequently encountered invasions in the brown and brook trout were ciliates: Chilodonella pisci­cola and Apiosoma conicum, Trichodina (in particular T. truttae and T. nigra), Ichtyophthirius multifiliis; monogenea Gy­rodactylus birmani, and diplostoma Diplostomum spathaceum. Aeromonas and Flavobacterium bacteria were isolated from fry and young-of-the-year rainbow trout and brook trout. Y. ruckeri positive samples were isolated from the fish with the signs of yersiniosis. As for viral diseases, IPNV isolates (the first time in Ukraine) of the rainbow trout were first isolated in fish farms in the western regions of Ukraine. A phylogenetic analysis of these IPNV isolates was performed, which showed that they belonged to Sp strain and the European genotype.

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