The invasion route of the gill parasite Urocleidus adspectus Mueller, 1936 (Monogenea: Ancyrocephalinae)

1981 ◽  
Vol 59 (11) ◽  
pp. 2166-2171 ◽  
Author(s):  
D. K. Cone ◽  
M. D. B. Burt
Keyword(s):  
Body Surface ◽  
Yellow Perch ◽  
Buccal Cavity ◽  
Experimental Studies ◽  
Perca Flavescens ◽  
The Body ◽  
Full Length ◽  
Gill Parasite ◽  
Young Of The Year

Urocleidus adspectus is transmitted experimentally to yellow perch (Perca flavescens) and the route of invasion and the behaviour of the parasite during the migration to the gills of the host is studied.The oncomiracidia invade the full length of the host and. as postoncomiracidia, attach at secluded sites such as beneath scales, at the base of fins, and in nooks in the body surface. The postoncomiracidia gradually migrate anteriorly and reach the gills by entering the opercular cavity and possibly the buccal cavity. In young-of-the-year perch, migrating worms appear to invade the primary lamella from the base or from the distal tip. In older perch the majority appear to invade the primary lamella from the base. Over 90% of the postoncomiracidia reach the gills of the young perch by day 5 postinfection and experimental studies indicate that few worms are dislodged during the migration.

Responses of Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) Populations to Removal of White Sucker (Catostomus commersoni) from a Minnesota Lake, 1966

1977 ◽  
Vol 34 (10) ◽  
pp. 1633-1642 ◽  
Author(s):  
Fritz H. Johnson
Keyword(s):  
Species Interactions ◽  
Standing Crop ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Food Competition ◽  
Community Response ◽  
Stizostedion Vitreum ◽  
Catostomus Commersoni ◽  
Young Of The Year ◽  
Fish Species Diversity

In a northeastern Minnesota lake subject only to sportfishing, removal of 85% of the estimated standing crop (34 kg/ha) of adult white suckers, Catostomus commersoni in 1966 was followed by marked changes in community structure and interrelations. During 7 yr alter the removal: catch indices for adult suckers remained far below those before the sucker removal but juvenile suckers increased about 17-fold; yellow perch, Perca flavescens, increased about 15-fold; walleye Stizostedion vitreum vitreum, standing crop increased about one-third; mayflies increased in diet of adult perch and smaller invertebrates decreased; micro-crustaceans increased in diet of young-of-the-year and juvenile perch; young-of-the-year perch increased in diet of adult walleye; walleye angling yield increased from an average of 3.0 kg/ha before the removal to an average of 4.9 kg/ha in 1970–73; the rate of exploitation of adult walleye did not change with increase in angling effort; and the increased walleye harvest consisted mostly of fish recruited to the catch during the fishing season. The average annual harvest of walleye in 1970–73 exceeded estimated potential production for all fish by 81.5% and probably cannot be sustained. Removal of white suckers from lakes with limited fish species diversity appears to benefit percid populations. Key words: Percidae, species interactions, (Stizostedion vitreum vitreum), Perca flavescens, Catostomus commersoni, harvests, community response, community ecology, food, competition

The ultrastructure of the fore-gut of the redia of Parorchis acanthus Nicoll (Digenea: Philophthalmidae) from the digestive gland of Nucella lapillus L

Parasitology ◽  
1983 ◽  
Vol 87 (1) ◽  
pp. 151-158 ◽  
Author(s):  
F. Gwendolen Rees
Keyword(s):  
Digestive Gland ◽  
Body Surface ◽  
Buccal Cavity ◽  
The Body ◽  
Unusual Feature ◽  
Nucella Lapillus ◽  
Cytoplasmic Inclusions ◽  
Parorchis Acanthus ◽  
Ventral Nucleus ◽  
Rapid Passage

SUMMARYThe fore-gut of the redia of Parorchis acanthus is ingestive in function. It consists of a buccal cavity, suctorial pharynx and an oesophagus divided into anterior and posterior regions. The syncytial lining is continuous with that covering the body surface, except for the posterior region of the oesophagus which is lined by a separate syncytium. This latter has different cytoplasmic inclusions and the unusual feature of a single ventral nucleus in the outer cytoplasmic epidermis. Intrinsic and extrinsic muscles are responsible, respectively, for the fairly rapid passage of food through the fore-gut and for support. Secretion bodies in the epidermis are probably discharged into the lumen and pass with food into the intestine where they may be involved in extracellular digestion. Young rediae feed mainly by mouth while older, immotile rediae absorb nutrients mainly through the body surface.

scholarly journals Vibrio cholerae Colonization of Soft-Shelled Turtles

2017 ◽  
Vol 83 (14) ◽  
Author(s):  
Jiazheng Wang ◽  
Meiying Yan ◽  
He Gao ◽  
Xin Lu ◽  
Biao Kan
Keyword(s):  
Animal Model ◽  
Vibrio Cholerae ◽  
Body Surface ◽  
Experimental Studies ◽  
Public Health Problem ◽  
Aquatic Organisms ◽  
Dorsal Side ◽  
The Body ◽  
Foodborne Disease ◽  
Content Type

ABSTRACT Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae-contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N-acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological investigations, no experimental studies have demonstrated the colonization by V. cholerae on soft-shelled turtles. The present studies will benefit our understanding of the interaction between V. cholerae and the soft-shelled turtle. We demonstrated the colonization by V. cholerae on the soft-shelled turtle's body surface and in the intestine and revealed the different roles of major V. cholerae factors for colonization on the body surface and in the intestine. Our work provides experimental evidence for the role of soft-shelled turtles in cholera transmission. In addition, this study also shows the possibility for the soft-shelled turtle to serve as a new animal model for studying the interaction between V. cholerae and aquatic hosts.

Seasonal Changes of Fat Content in the Yellow Perch (Perca flavescens) of Two Laurentian Lakes

1975 ◽  
Vol 32 (11) ◽  
pp. 2214-2221 ◽  
Author(s):  
George E. Newsome ◽  
Gérard Leduc
Keyword(s):  
Body Fat ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Fat Content ◽  
The Body ◽  
Differential Mortality ◽  
Fat Reserves ◽  
Body Fat Content ◽  
Fat Level ◽  
Males And Females

Different body fat reserves in male and female yellow perch (Perca flavescens) may determine a marked differential mortality during the winter. This was revealed by a study in two Laurentian lakes of the Province of Quebec harboring stunted yellow perch with a marked predominance of males. The proportion of females in each year-class is markedly smaller, thus suggesting a higher mortality among immature and mature females than among males.In an attempt to explain the differential mortality, the seasonal variation of body fat content in males and females was measured; also the fat level at time of death caused by starvation under laboratory conditions was determined. The results showed that in the females the body fat content falls to a critical level of about 2% at least 4 mo before spawning, whereas the males maintain a fat level of almost 5% throughout winter.

Disruption of the hypothalamo-pituitary-interrenal axis in 1+ yellow perch (Perca flavescens) chronically exposed to metals in the environment

2005 ◽  
Vol 62 (5) ◽  
pp. 982-990 ◽  
Author(s):  
A Gravel ◽  
P GC Campbell ◽  
A Hontela
Keyword(s):  
Yellow Perch ◽  
Acute Stress ◽  
Stress Test ◽  
Perca Flavescens ◽  
Whole Body ◽  
Hepatosomatic Index ◽  
Physiological Status ◽  
Young Of The Year ◽  
First Time ◽  
Cu And Zn

Although it has been reported that adult yellow perch (Perca flavescens) chronically exposed to metals in the environment exhibit endocrine impairment characterized by blunted cortisol secretion, little is known about the vulnerability of early life stages. Young-of-the-year (YOY) and 1+ yellow perch were captured, subjected to a standardized stress test or adrenocorticotropic-hormone stimulation in lakes situated along a contamination gradient of Cd, Cu, and Zn in the mining region of Abitibi, Quebec. For the first time, whole-body cortisol concentrations were measured. The 1+ fish with elevated whole-body Cd, Cu, and Zn concentrations had an impaired capacity to respond to an acute stress challenge. Although YOY perch had similar whole-body Cd concentrations to 1+ perch, no effects on physiological status were detected in relation to body burdens of metals. Metal contamination did not affect whole-body thyroid-hormone concentrations, condition factor, or hepatosomatic index in 1+ or YOY perch. These results indicate that effects of Cd, Cu, and Zn on the functional integrity of the hypothalamo-pituitary-interrenal axis in yellow perch are detectable after only 1 year of environmental exposure.

Cyclic dynamics of a yellow perch (Perca flavescens) population in an oligotrophic lake: evidence for the role of intraspecific interactions

1999 ◽  
Vol 56 (9) ◽  
pp. 1534-1542 ◽  
Author(s):  
Beth L Sanderson ◽  
Thomas R Hrabik ◽  
John J Magnuson ◽  
David M Post
Keyword(s):  
Yellow Perch ◽  
Perca Flavescens ◽  
Age Classes ◽  
Intraspecific Interactions ◽  
Important Challenge ◽  
Cyclic Dynamics ◽  
Young Of The Year ◽  
Mature Fish

Understanding the extent to which repeated oscillations in fish populations are driven by external factors or internal processes within the population is an important challenge. We document cyclic dynamics in a population of yellow perch (Perca flavescens) in oligotrophic Crystal Lake. Since 1981, we have observed three cases of cohort dominance in which two age-classes dominated the population for roughly 5 years. Young-of-the-year (YOY) perch were caught in 1981-1982, 1986-1987, and 1990-1991, whereas few to no YOY were caught during the midyears. The presence of YOY was negatively related to juvenile perch abundance and positively related to adult perch abundance. Mechanisms that may be responsible for these patterns include cannibalism of YOY by either juveniles or adults, potential for reproduction by adults, and competition between YOY and juveniles. YOY were abundant primarily in years when reproductively mature fish were in the lake, suggesting that the repeated oscillations are driven predominantly by pulses of abundant, reproductive, adult perch. As these young perch grow to juveniles, they exclude the possibility of survival by successive cohorts through cannibalistic and competitive interactions. This exclusion occurs until they themselves become reproductively mature and the cycle then repeats. Ultimately, long-term patterns in Crystal Lake suggest that cyclic dynamics are generated by intraspecific interactions.

Some Behavioral Interactions of Spottail Shiners (Notropis hudsonius), Yellow Perch (Perca flavescens), and Northern Pike (Esox lucius)

1973 ◽  
Vol 30 (8) ◽  
pp. 1161-1178 ◽  
Author(s):  
J. R. Nursall
Keyword(s):  
Yellow Perch ◽  
Perca Flavescens ◽  
Northern Pike ◽  
Esox Lucius ◽  
Behavioral Interactions ◽  
Change Of Direction ◽  
Pike Esox Lucius ◽  
Glide Path ◽  
Beaver Lake ◽  
Young Of The Year

Dense schools of spottail shiners (Notropis hudsonius) are common in shallow water in Beaver Lake, generally 0.25–0.30 m below the surface, with smaller individuals more numerous towards the top. Position in the shcool is maintained by short radius behavior. The course of an individual is maintained by a beat of the tail, a glide, a hesitation, and a change of direction. Each glide path represents the chord of an arc of short radius about some neighbor. Shiners respond to disturbance by flash expansion of loose cruising association. Schooling is obligatory. The black caudal spot is probaly multifunctional as a recognition mark and releaser.Yellow perch (Perca flavescens) show an ontogeny of behavior through young-of-the-year, aggregation-sized perch (aggp), subadults, and adults. They behave as individuals or associate as streams. Disturbance will cause a group of aggp to disperse or to stream. The adult manifestation of streaming is pack-hunting. The activity of one perch attracts the attention of others; this leads to streaming or pack-hunting. Pack-hunting improves the chance of some members of the pack, not necessarily the initiator, capturing active prey, by countering the allaesthetic protean escape reactions of organisms such as the spottail shiner. Large mixed aggregations of spottail shiners and aggp are fortuitous.Northern pike (Esox lucius) are lone, opportunistic predators whose hunting technique combines in sequence motionlessness, axial tracking, and lunging. Prey may be swallowed head- or tailfirst, or sideways.The species studied here show a range of gregariousness, from the solitary pike, through the facultative nonpolarized and polarized schools of perch, to obligate nonpolarized and polarized schools of shiners.

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