Within-population variability in egg characteristics of walleye (Stizostedion vitreum) and white sucker (Catostomus commersoni)

1997 ◽  
Vol 54 (5) ◽  
pp. 1006-1014 ◽  
Author(s):  
T A Johnston

I examined variation in egg characteristics among individual females of sympatrically spawning walleye (Stizostedion vitreum) and white sucker (Catostomus commersoni) from Lake Manitoba. White sucker produced eggs of greater dry mass and energy content than walleye. Walleye egg dry mass varied between years and was positively related to both female length and age. The relationship between white sucker egg dry mass and female length varied between years. Egg energy density did not vary with respect to female length in either species. Egg energy density varied between years for walleye but not white sucker. Hatching success of walleye eggs was positively related to female age and negatively related to female length adjusted for age. Length and dry mass of walleye larvae at hatch increased with egg dry mass. Results suggest that the quality of eggs produced by walleye and white sucker populations may vary with the size and age structure of the populations and among spawning years.

1990 ◽  
Vol 47 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Molly O. Ahlgren

The ash-free dry mass (AFDM) of detritus, invertebrates, and algae in the diet of juvenile white sucker (Catostomus commersoni) was determined by quantitative microscopy. Fish were collected from a northern Michigan pond from January through October 1986 and their seasonal diet was compared with benthc invertebrate abundance. The quantity of detritus in sucker foreguts was inversely related to benthic microcrustacean densities. In July, microcrustacean densities were high and they comprised 95% of the AFDM in foregut contents. By October, microcrustacean densities had declined to 13% of their maximum density and detritus comprised over 90% of the sucker's diet AFDM. In laboratory aquaria, sucker that were fed detritus mixed with four different densities of Artemia ingested significantly more detritus from diets that provided lower Artemia densities. In the presence of high Artemia densities, sucker completely rejected detritus and ingested only Artemia, The fact that juvenile sucker can separate detritus from invertebrates that they swallow demonstrates that detritus is not ingested incidentally. Both laboratory and field data support the hypothesis that detritus is ingested intentionally when preferred invertebrate prey are scarce.


1997 ◽  
Vol 54 (1) ◽  
pp. 190-197 ◽  
Author(s):  
P Hamel ◽  
P Magnan ◽  
P East ◽  
M Lapointe ◽  
P Laurendeau

We performed laboratory incubations of white sucker (Catostomus commersoni) eggs to determine (i) the incubation time to organogenesis, eyed egg, hatching, and swim-up phases at eight different temperatures (8.5-21.2°C), and (ii) the best model to describe the relationship between these incubation times and temperature. Seven models (degree-day, power-law, B e lehrádek's equation, quadratic equation, first- and second-order exponentials, and a thermodynamic model) all gave comparable and highly significant fits to our data (R2 > 0.90). We thus compared the in situ and predicted incubation times by (i) the degree-day model, because of its simplicity, and (ii) the thermodynamic model, because of its theoretical foundation. The degree-day model was at least as accurate as the thermodynamic model (overall mean difference between predicted and observed incubation times of 1.4 ± 1.0 and 1.2 ± 1.2 days for the thermodynamic and degree-day models, respectively). Given its high accuracy and simplicity of use, we conclude that the degree-day model should be used to predict the incubation times of white sucker. We also observed a synchronization of hatching in situ that suggested an influence of photoperiod in addition to that of water temperature.


2020 ◽  
Vol 44 ◽  
Author(s):  
Hugo Cesar Rodrigues Moreira Catão ◽  
Franciele Caixeta ◽  
Amanda Moreira Lopes ◽  
Flavia Andrea Nery-Silva ◽  
Adílio de Sá Júnior

ABSTRACT Salinity influences all germination stages and may adversely affect seedling establishment in the field. The objective of this research was to determine the relationship between the antioxidant activity and the physiological performance of seeds and to verify the efficacy of the imaging analysis of popcorn seedlings after seed exposure to saline stress. A completely randomized design was used that consisted of four replicates in a factorial scheme. This scheme comprised three popcorn hybrids (P618, AP6002, and AP8203) and five saline potential levels (0.0; -0.1; -0.3; -0.6, and -0.9 MPa) that were obtained from KCl solutions of different concentrations. First count germination, germination and seedling vigor classification (strong normal seedlings), and dry mass of seedlings were evaluated to determine the physiological quality of the seed. The images of seedlings were used to evaluate the coleoptile and root lengths, indices of vigor, uniformity, and growth using the Groundeye® software. The activities of the antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) were also determined. Saline stress compromises the physiological quality and antioxidant activity of seeds and the performance of popcorn seedlings. Computerized image analysis using Groundeye® was efficient in evaluating the popcorn seedlings after being subjected to salt stress. Hybrids AP6002 and AP8203 were more tolerant to salt stress than hybrid P618.


1969 ◽  
Vol 26 (12) ◽  
pp. 3266-3267 ◽  
Author(s):  
G. H. Lawler

On the basis of the numbers of fish caught per unit of time in Heming Lake during a spring–summer period, the white sucker (Catostomus commersoni) was most active during daylight. The following species were most active during darkness: northern pike (Esox lucius), whitefish (Coregonus clupeaformis), and walleye (Stizostedion vitreum vitreum).


2017 ◽  
Vol 65 (1-1) ◽  
pp. 197
Author(s):  
Paula F. Cossi ◽  
Claudia C. Boy ◽  
Analía F. Pérez

Energy allocation patterns during the reproductive cycle of echinoderms may be determined by the different energy requirements of the organisms. In this study, we describe the energy reserves variation in the gonads, pyloric caeca and stomach among the gametogenic stages of a population of Cosmasterias lurida from the Beagle Channel, Argentina. Adult individuals of C. lurida were collected from the subtidal zone of Ushuaia Bay during four seasonal sampling periods (August 2010 to June 2011). Indices, energy density (kJ/g ash-free dry mass) and energy content (kJ) of gonads, pyloric caeca and stomach were determined. Oocytes number and diameter were evaluated. Cosmasterias lurida had a major peak of gonadal index (GI) in mature gonads (M), with a great decrease towards the spawning (PS/PSR) and remature (RM) periods. No variation was observed in the energy density of the gonads (EDG). The energy content of the gonads (ECG) presented a similar pattern to the GI. Thus, the gonadal storage cycle can be explained through the variation in gonad mass more than in its energy density. Females had higher ECG and EDG values than males, which suggest a greater energy contribution in females during the reproductive cycle. The stomach and the pyloric caeca indices, energy density and energy content remained unaltered among the stages. The energy density of pyloric caeca (EDPC) was higher in mature males than in mature females. Likewise, the energy density of the stomach (EDS) was overall higher in males than in females. This inverse pattern between sexes in relation to the EDG may suggest a transference of energy from the pyloric caeca and stomach to gonads during maturate stage playing a storage role for reproduction. Rev. Biol. Trop. 65(Suppl. 1): S197-S206. Epub 2017 November 01. 


2005 ◽  
Vol 62 (12) ◽  
pp. 2706-2715 ◽  
Author(s):  
Andrea Bertolo ◽  
Pierre Magnan

We used data from a survey of 36 headwater lakes of the Canadian Shield to investigate the relationship between piscivory and growth, abundance, and longevity of white sucker (Catostomus commersoni) and yellow perch (Perca flavescens). The occurrence of northern pike (Esox lucius) and walleye (Sander vitreus) explained variations in the abundance of both white sucker and yellow perch, suggesting strong predation-induced mortality. The longevity of both species tended to be negatively related to increased piscivory. White sucker grew better and had a better condition in lakes with piscivores. Yellow perch showed only small among-lake differences in growth and condition. The superior competitive ability of white sucker over yellow perch could explain why yellow perch did not show improved growth or longevity where population densities were low in lakes with piscivores and white sucker. Furthermore, yellow perch growth was inversely related to the biomass of piscivorous fish in their first year of life. Stomach content data suggest that small yellow perch, which rely on zooplankton, might restrict their use of pelagic resources to reduce their predation risk by piscivores, thus reducing their growth. Our results show that the effects of piscivores can be species-specific and dependent on community structure.


2020 ◽  
Vol 8 (2) ◽  
pp. 407
Author(s):  
Joner Silveira Dalcin ◽  
Caren Alessandra Müller ◽  
Ubirajara Russi Nunes ◽  
Rodrigo Roso ◽  
Alberto Cargnelutti Filho ◽  
...  

Rapid tests such as electrical conductivity provide fast and consistent results regarding stratification of seed lots by vigor. They are important tools used to evaluate the physiological quality of seeds of several species, however, no such information was found for Sorghum bicolor. The objective of this study was to evaluate the relationship between the physiological quality of the seeds by the mass and individual conductivity tests. Four plots of the Fepagro 19 cultivar were analyzed through the degree of moisture, weight of one thousand seeds, first count and germination, radicular and shoot length, dry mass, cold test and emergence of field seedlings. Subsequently, they were submitted to mass electrical conductivity experiments with variations in the imbibition time (2, 4, 6, 8, 12 and 24 hours), temperature (20, 25 and 30 ºC), number of seeds (25 and 50), volume of water (50 and 75 mL) and individual (2, 4, 6, 8, 12 and 24 hours). The design was completely randomized and the data evaluated by the Tukey test. Only the lowest physiological quality batch was detected in the 20 °C, 75 mL and 25 seeds for 12 hours combinations; the individual test detected the least physiological quality batch, and it was possible to perform it in 24 hours.


1990 ◽  
Vol 47 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Molly O. Ahlgren

The nutritional significance of detritus in the diet of the juvenile white sucker (Catostomus commersoni) was evaluated by experiments designed to assess assimilation efficiency and growth of sucker fed detritus and other foods. Sucker in laboratory aquaria assimilated detritus with the following efficiencies: dry mass = 19.6%, ash-free dry mass (AFDM) = 59.7%, total amino acids = 68.9%, energy = 69.4%. Assimilation efficiencies calculated for invertebrates and natural field diets were slightly higher. Diatom assimilation was low (5.5%). In growth experiments, sucker fed detritus ad libitum lost weight, while those fed Artemia ad libitum grew rapidly. However, detritus increased the growth rate of sucker fed a limited invertebrate ration and reduced the rate of weight loss relative to unfed fish. The ratio of digestible protein to digestible energy calculated for natural detritus diets (3.2 mg amino acid/kj) indicates that the protein content of detritus is too low to support growth. Detritus provides energy which complements limited invertebrate protein to enhance growth or reduce the rate of weight loss when invertebrate prey are not available.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1966
Author(s):  
Yang Liu ◽  
Mingxuan Li ◽  
Xiaofeng Lu ◽  
Xiaolei Zhu ◽  
Peng Li

During the process of laser powder bed fusion (LPBF) printing, the energy of heat input have a great influence on the quality of fabricated specimens. In this paper, based on the heat transfer and metallurgical mechanism, a theoretical predicting model of the required laser energy to fabricate high-density LPBF components was established. The theoretical required laser energy density of AlSi10Mg, TC4 and 316L were calculated, which are 51.74 J/mm3, 104.48 J/mm3 and 69.28 J/mm3, respectively. By comparing with the experimental results in the references, it was found that the errors between them are within 10%. In addition, this article discussed the relationship between the VED and the specimen defects, and found that the changing in the VED will alter the types of specimen defects.


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