scholarly journals Digestive enzyme system of larvae of different freshwater teleosts and its differentiation during the initial phase of exogenous feeding

2017 ◽  
Vol 62 (No. 10) ◽  
pp. 403-416 ◽  
Author(s):  
F. Lahnsteiner
Keyword(s):  
Digestive System ◽  
Enzyme System ◽  
Digestive Enzyme ◽  
Sander Lucioperca ◽  
Thymallus Thymallus ◽  
Exogenous Feeding ◽  
First Feeding ◽  
Histological Characteristics ◽  
Species Specific ◽  
Freshwater Teleosts

Activities of digestive enzymes and main histological characteristics of the intestine were investigated in larvae of three salmonid species (Coregonus maraena, C. atterensis, Thymallus thymallus), of burbot (Lota lota), and pikeperch (Sander lucioperca) at the onset of exogenous feeding (0 day degrees (°d)) and at 250°d thereafter. At the onset of exogenous feeding the activities of proteolytic, lipolytic, and carbohydrate splitting enzymes were detected in the intestines of all species. The enzymatic activities showed significant species specific differences indicating specializations in functionality and digestion ability. In C. atterensis and L. lota the activities of most enzymes were low in comparison to the other investigated species and therefore their digestive system was only poorly developed. In S. lucioperca it was moderately developed and in T. thymallus and C. maraena well-developed. After 250°d, the activities of the investigated enzymes changed in a very species specific way. Histologically, the intestines of the investigated species revealed no species specific differentiations at the onset of the first feeding with the exception of the absence of goblet cells in L. lota and C. atterensis. These differentiated after 250°d.

Effects of first feeding regime on growth performance, survival rate and development of digestive system in pikeperch (Sander lucioperca) larvae

Aquaculture ◽  
2020 ◽  
Vol 529 ◽  
pp. 735636
Author(s):  
Aiman Imentai ◽  
Božidar Rašković ◽  
Christoph Steinbach ◽  
Samad Rahimnejad ◽  
Carlos Yanes-Roca ◽  
...  
Keyword(s):  
Survival Rate ◽  
Growth Performance ◽  
Digestive System ◽  
Sander Lucioperca ◽  
Feeding Regime ◽  
First Feeding

Mortality of First-Feeding Postlarval Walleye (Stizostedion vitreum) in Culture Ponds

1993 ◽  
Vol 50 (9) ◽  
pp. 1835-1843 ◽  
Author(s):  
Thomas A. Johnston ◽  
J. A. Mathias
Keyword(s):  
Critical Period ◽  
Mortality Rates ◽  
Predation Pressure ◽  
Stizostedion Vitreum ◽  
Exogenous Feeding ◽  
Natural Lakes ◽  
First Feeding ◽  
Zooplankton Density ◽  
Food Concentrations ◽  
Order Of Magnitude

We examined mortality rates of postlarval walleye (Stizostedion vitreum) at the onset of exogenous feeding in extensive culture ponds. Food concentrations (≥49 zooplankters∙L−1) were apparently sufficient to support successful first feeding, and no critical period of starvation mortality was evident at this stage of life. The highest observed mortality rates were associated with interspecific or intraspecific predation pressure. At low predation pressure, mean survival from stocking to the 12-mm stage was 87% in 1988 and 90% in 1989, and instantaneous mortality rates were an order of magnitude lower than those reported for postlarval walleye in natural lakes. Mortality rates calculated over the early postlarval period (stocking to 12 mm; 9–11 d) were similar to those calculated over the entire culture period (88–107 d) when predation pressure was low. At low predation pressure and 49–159 zooplankters∙L−1, there was no significant relationship between postlarval mortality rates and zooplankton density. The condition of first-feeding postlarvae captured from the pond with the lowest mean zooplankton density (49∙L−1) was significantly higher than that of postlarvae deprived of food for 48 h. Starvation is probably not a major cause of postlarval morality when zooplankton densities are ≥50∙L−1.

scholarly journals Low turbidity in recirculating aquaculture systems (RAS) reduces feeding behaviour and increases stress-related physiological parameters in pikeperch (Sander lucioperca) during grow-out

2021 ◽  
Author(s):  
Stephan S W Ende ◽  
Ekaterina Larceva ◽  
Mirko Bögner ◽  
Vincent Lugert ◽  
Matthew James Slater ◽  
...  
Keyword(s):  
Feed Intake ◽  
Economic Consequences ◽  
Feeding Time ◽  
Sander Lucioperca ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems ◽  
Body Weights ◽  
High Turbidity ◽  
And Performance ◽  
Species Specific

Abstract There is a tendency to farm fish in low turbidity water when production takes place in the land-based recirculating aquaculture systems (RAS). However, the effect of water turbidity on stress and performance is unknown for many species cultured in RAS. The effect of different turbidity treatments as Formazine Attenuation Units (0 FAU, 15 FAU, and 38 FAU) on feed intake performance (latency, total feeding time, and total feed intake) and physiological blood stress parameters (cortisol, lactate, and glucose) in medium-sized pikeperch ((Sander lucioperca) n = 27, undetermined sex and age) of initial body weights of 508.13g ± 83 g (at FAU 0, 15 and 38, respectively) was investigated. The rearing system consisted of 9 rectangular tanks (200 L per tank). Fish were housed individually (n = 1, per tank, n replicates per treatment = 9). All tanks were connected to a recirculation system equipped with a moving bed biofilter. Feed intake in pikeperch kept at low turbidity (0 FAU) was 25% lower than pikeperch kept at high turbidity (38 FAU) (P<0.01) and also significantly (10.5%) lower compared to feed intake in pikeperch kept at intermediate turbidity (15 FAU) (P<0.01 for 0 FAU vs 15 FAU, feed intake sign. Value as the main effect is P<0.01). Pikeperch kept at low turbidity showed significantly slower feeding response (latency time) towards pellets entering the tank, shorter feeding times (both P< 0.05), and higher glucose blood concentration (73%) in contrast to pikeperch kept at highest turbidity. A reduction of 25% feed intake has obvious economic consequences for any fish farm and present data strongly emphasize the importance of considering the species-specific biology in future RAS farming.

scholarly journals Comparative Histological and Phytochemical Study of Fallopia Species

2016 ◽  
Vol 11 (2) ◽  
pp. 1934578X1601100
Author(s):  
Heléna Békési-Kallenberger ◽  
Györgyi Horváth ◽  
Tímea Bencsik ◽  
Viktória Lilla Balázs ◽  
Rita Filep ◽  
...  
Keyword(s):  
Flowering Period ◽  
Japanese Knotweed ◽  
Tannin Content ◽  
Fallopia Japonica ◽  
Phytochemical Study ◽  
Histological Characteristics ◽  
Giant Knotweed ◽  
Species Specific ◽  
Asian Herbal Medicine ◽  
Stem Leaf

Fallopia species which belong to the Polygonaceae family have several data related to their use in the Asian herbal medicine. In this work, some histological and phytochemical parameters of Fallopia japonica, F. sachalinensis, and F. × bohemica were analysed and compared. Rhizome and leaf samples were collected before, during, and after the flowering period at 3 habitats in Szombathely and 4 habitats in Baranya County, Hungary. The main histological characteristics of the stem, leaf and petiole were studied by light microscopy in cross section. Total tannin and anthraquinone contents were determined according to the official methods of the Hungarian Pharmacopoeia VIIIth (equal to the European Pharmacopoeia 6th). No species-specific markers were found in any plant part. In the rhizome, the highest tannin content was measured in Japanese knotweed, followed by Bohemian and giant knotweed in each period. The tannin content measured in each plant was higher in the leaves than in the rhizomes except F. japonica. The rhizome of F. japonica had the highest anthraquinone content before the flowering period, followed by F. × bohemica and F. sachalinensis. According to earlier and our preliminary data, Fallopia taxa are of great therapeutic promise in the future.

Effect of Brachionus plicatilis density on pikeperch ( Sander lucioperca L.) larva performance at first feeding

2019 ◽  
Vol 35 (6) ◽  
pp. 1292-1294 ◽  
Author(s):  
Aiman Imentai ◽  
Carlos Yanes‐Roca ◽  
Oleksandr Malinovskyi ◽  
Tomáš Policar
Keyword(s):  
Brachionus Plicatilis ◽  
Sander Lucioperca ◽  
First Feeding

scholarly journals Sperm morphology, ultrastructure, and motility in pikeperch Sander lucioperca (Percidae, Teleostei) associated with various activation media 

2014 ◽  
Vol 59 (No. 1) ◽  
pp. 1-10 ◽  
Author(s):  
J. Křišťan ◽  
A. Hatef ◽  
S.M.H. Alavi ◽  
T. Policar
Keyword(s):  
Sperm Morphology ◽  
Storage Period ◽  
Spherical Nucleus ◽  
Sander Lucioperca ◽  
Central Pair ◽  
Spermatozoa Motility ◽  
Sampling Times ◽  
Freshwater Teleosts

Spermatozoa morphology, ultrastructure, and spermatozoa motility traits were studied in pikeperch (Sander lucioperca) after activation in various media (AM 1 &ndash; 45mM NaCl, 5mM KCl, 20mM Tris, pH 8.5; AM 2 &ndash; 100mM sucrose, 20mM Tris, pH 8.5; AM 3 &ndash; 100mM sucrose, 1mM CaCl<sub>2</sub>, 20mM Tris, pH 8.5) during a 48-hour storage period. The spermatozoon was acrosomeless and differentiated into a spherical nucleus (head), midpiece, and flagellum. The nucleus length and width measured 1.83 &plusmn; 0.03 and 1.63 &plusmn; 0.02&nbsp;mm, respectively. The midpiece was located laterally to the nucleus and possessed proximal and distal centrioles and 2&ndash;4 mitochondria. Flagellar length was 33.2 &plusmn; 0.90 &micro;m, and a pair of lateral fin-like structures projections was observed. The axoneme consisted of nine peripheral doublet microtubules and a single central pair. After a 24 h storage in all activation media at all sampling times post-activation (15, 45, 90, and 120 s), spermatozoa motility was significantly decreased. Spermatozoa were motile after the 48-hour storage at all sampling times post-activation only in AM 3. After the 48-hour storage, no motile spermatozoa were observed in AM 2 and AM 1 at 90 and 120 s post-activation, respectively. Differences in spermatozoa velocity varied with activation medium during storage. After the 48-hour storage in AM 1 and AM 2, decrease of spermatozoa velocity at 15 s post-activation was observed, while in AM 3, velocity was decreased only after the 48-hour storage. Pikeperch spermatozoa morphology and ultrastructure was found similar to that of most freshwater teleosts, with differences in the arrangement of midpiece, number of mitochondria, and position of centrioles. Viable pikeperch sperm was observed after the 48-hour storage. Motility of spermatozoa was improved by addition of Ca<sup>2+</sup> to the activation medium, where higher spermatozoa velocity was observed.

Ontogeny of Feeding Behavior of First-Feeding Atlantic Salmon (Salmo salar)

1991 ◽  
Vol 48 (10) ◽  
pp. 1896-1904 ◽  
Author(s):  
David J. Coughlin
Keyword(s):  
Atlantic Salmon ◽  
Feeding Behavior ◽  
Salmo Salar ◽  
Exogenous Feeding ◽  
Feeding Mode ◽  
Atlantic Salmon Salmo Salar ◽  
First Feeding ◽  
Swimming Motion ◽  
In The Wild ◽  
Time To Learn

Feeding strikes of Atlantic salmon (Salmo salar) alevins preying upon Daphnia are described using videorecording of synchronous lateral and antero-ventral views. Based on examination of characteristics such as aiming inaccuracy and capture distance, it is demonstrated that feeding behavior significantly improves during the first 2 wk after initiation of exogenous feeding. With increasing experience, young salmon tend to capture prey more quickly and with greater accuracy. First-feeding alevins use a body-ram feeding mode, relying on their swimming motion to overtake and capture prey. After 7–10 d of feeding, the fish change to a suction feeding mode that effectively uses suction generated by expansion of the orobranchial chamber to pull in prey from a distance. Also, feeding behavior of alevins raised on a commercial salmon feed lags developmentally behind the behavior offish raised on live food. This lag time is short (2–3 d), indicating that despite reports to the contrary, hatchery-raised fish do not require a Song time to learn to capture prey effectively in the wild.

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