scholarly journals Exotic plus native: findings in an unscheduled fish duoculture

2021 ◽  
Vol 49 (4) ◽  
pp. 649-653
Author(s):  
David Julián Palma-Cancino ◽  
Mao Ernesto Rafael Basto-Rosales ◽  
Carlos Alfonso Álvarez-González ◽  
Rafael Martínez-García ◽  
Daniel Badillo-Zapata ◽  
...  
Keyword(s):  
Native Species ◽  
Good Alternative ◽  
Native Fish ◽  
Sustainable Aquaculture ◽  
Feed Conversion ◽  
Exotic Fish ◽  
Biological Variables ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Concrete Tank ◽  
Feed Conversion Rate

The development of native fish aquaculture represents an important alternative to mitigate ecological displacement generated by exotic fish. The introduction of native fish in polyculture systems with high commercial value fishes has provided a useful strategy for sustainable aquaculture development. The present study aims to provide information on tilapia, as an exotic species, and Dormitator latifrons, as a native species, in a duo culture not programmed as such. Using juveniles of Pacific fat sleeper D. latifrons leftovers from another experiment, we decide to analyze and report the biological feasibility of a duoculture system with this species and Nile tilapia (Oreochromis niloticus). Two hundred fifty organisms of each species were placed for 90 days in a concrete tank with a capacity of 50 m3 to evaluate the compatibility of these species. The biological variables measured were growth, survival, feed conversion rate, and protein efficiency. The findings suggest a good interaction between species, with adequate growths and a survival rate of 98%. No antagonistic behavior was observed during confinement, suggesting the duoculture of these species may represent a good alternative for tropical sustainable aquaculture.

scholarly journals Productive performance of Nile tilapia (Oreochromis niloticus) fed at different frequencies and periods with automatic dispenser

2012 ◽  
Vol 64 (1) ◽  
pp. 192-197 ◽  
Author(s):  
R.M.R. Sousa ◽  
C.A. Agostinho ◽  
F.A. Oliveira ◽  
D. Argentim ◽  
P.K. Novelli ◽  
...  
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Productive Performance ◽  
Feed Conversion ◽  
Feeding Frequency ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Significant Difference ◽  
Final Weight ◽  
Autumn And Winter ◽  
Feed Conversion Rate

The performance of Nile tilapia (Oreochromis niloticus) raised in cages furnished with an automatic dispenser, supplied at different frequencies (once per hour and once every two hours) and periods (daytime, nighttime and both) was evaluated. Eighteen 1.0m³ cages were placed into a 2000m² pond, two meters deep with a 5% water exchange. One hundred and seventy tilapias, with initial weight of 16.0±4.9g, were dispersed into each 1m³ cage and the feed ration was adjusted every 21 days with biometry. Data was collected from March to July (autumn and winter). Significant difference to final weight (P<0.05) among treatments was observed. The increase in feeding frequency improves the productive performance of Nile tilapias in cages and permitted better management of the food. The better feed conversion rate for high feeding frequency (24 times day-1) can result in saving up to 360kg of food for each ton of fish produced, increasing the economic sustenance for tilapia culture and suggesting less environmental pollution.

scholarly journals Growing, losing or introducing? Cage aquaculture as a vector for the introduction of non-native fish in Furnas Reservoir, Minas Gerais, Brazil

2011 ◽  
Vol 9 (4) ◽  
pp. 915-919 ◽  
Author(s):  
Valter Monteiro de Azevedo-Santos ◽  
Odila Rigolin-Sá ◽  
Fernando Mayer Pelicice
Keyword(s):  
Native Species ◽  
Native Fish ◽  
Species Introduction ◽  
Hydroelectric Reservoirs ◽  
Fish Introductions ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Management Procedures ◽  
Cage Aquaculture ◽  
Historical Relationship ◽  
Aquaculture Facilities

Cage aquaculture has been developed in many countries, including Brazil. This form of production, although economically productive, may cause several impacts to the environment. Considering the historical relationship between aquaculture and species introduction, our study investigated the potential of cage aquaculture in spreading non-native species into hydroelectric reservoirs. We interviewed 19 fish farmers in Furnas Reservoir, Grande River basin. All producers have grown exclusively Nile tilapia (Oreochromis niloticus), an African fish, and all producers reported the occurrence of fish escapes. Releases were mainly accidental, but highly frequent during some management procedures, such as length classification, fish capture and juvenile stocking. Escapes were also reported due to cage damage and deliberate releases. These results indicate that, in cage aquaculture facilities, fish are frequently released to the external environment. When raising non-native species (e.g. Furnas Reservoir), these facilities constitute an important vector for fish introductions.

scholarly journals Differences in sensitivity of native and exotic fish species to changes in river temperature

2011 ◽  
Vol 57 (6) ◽  
pp. 852-862 ◽  
Author(s):  
R.S.E.W. Leuven ◽  
A.J. Hendriks ◽  
M.A.J. Huijbregts ◽  
H.J.R. Lenders ◽  
J. Matthews ◽  
...  
Keyword(s):  
Exotic Species ◽  
Fish Species ◽  
Native Species ◽  
Temporal Trends ◽  
Fish Fauna ◽  
Native Fish ◽  
Fish Diversity ◽  
Exotic Fish ◽  
River Temperature ◽  
Exotic Fish Species

Abstract This paper describes the effects that temperature changes in the Rhine river distributaries have on native and exotic fish diversity. Site-specific potentially affected fractions (PAFs) of the regional fish species pool were derived using species sensitivity distributions (SSDs) for water temperature. The number of fish species in the river distributaries has changed remarkably over the last century. The number of native rheophilous species declined up until 1980 due to anthropogenic disturbances such as commercial fishing, river regulation, migration barriers, habitat deterioration and water pollution. In spite of progress in river rehabilitation, the native rheophilous fish fauna has only partially recovered thus far. The total number of species has strongly increased due to the appearance of more exotic species. After the opening of the Rhine-Main-Danube waterway in 1992, many fish species originating from the Ponto-Caspian area colonized the Rhine basin. The yearly minimum and maximum river temperatures at Lobith have increased by circa 4 0C over the period 1908-2010. Exotic species show lower PAFs than native species at both ends of the temperature range. The interspecific variation in the temperature tolerance of exotic fish species was found to be large. Using temporal trends in river temperature allowed past predictions of PAFs to demonstrate that the increase in maximum river temperature negatively affected a higher percentage of native fish species than exotic species. Our results support the hypothesis that alterations of the river Rhine’s temperature regime caused by thermal pollution and global warming limit the full recovery of native fish fauna and facilitate the establishment of exotic species which thereby increases competition between native and exotic species. Thermal refuges are important for the survival of native fish species under extreme summer or winter temperature conditions.

Long-term changes of the Lake Michigan fish community following the reduction of exotic alewife (Alosa pseudoharengus)

2006 ◽  
Vol 63 (11) ◽  
pp. 2434-2446 ◽  
Author(s):  
David B Bunnell ◽  
Charles P Madenjian ◽  
Randall M Claramunt
Keyword(s):  
Native Species ◽  
Yellow Perch ◽  
Fish Community ◽  
Lake Michigan ◽  
Lake Trout ◽  
Native Fish ◽  
Trawl Survey ◽  
Alosa Pseudoharengus ◽  
Exotic Fish

We used our long-term annual bottom trawl survey (1973–2004) in Lake Michigan to reveal the response of the native fish community to the biological control of a dominant exotic fish, alewife (Alosa pseudoharengus), as well as to changes in total phosphorus and salmonine biomass. Through nonmetric multidimensional scaling, we documented a 1970s community largely dominated by alewife, and then a shift to a community dominated by several native species during the 1980s through 1990s, when alewife remained at relatively low levels. We argue that the recovery of burbot (Lota lota), deepwater sculpin (Myoxocephalus thompsonii), and yellow perch (Perca flavescens) was partially or fully aided by the alewife reduction. We argue that changes in phosphorus or salmonines were not directly related to abundance increases of native species. An additional community shift occurred during 1999–2004, which coincided with a reduction in species richness and total fish biomass in our trawl. The mechanisms underlying this latest shift may be related to reductions in nutrients, but further research is required. The restoration of the native fish community has been incomplete, however, as emerald shiner (Notropis atherinioides), cisco (Coregonus artedii), and lake trout (Salvelinus namaycush) have yet to demonstrate recovery.

scholarly journals Dietary fermented rapeseed or/and soybean meal additives on performance and intestinal health of piglets

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Czech ◽  
Eugeniusz Ryszard Grela ◽  
Martyna Kiesz
Keyword(s):  
Gastrointestinal Tract ◽  
Gut Microbiota ◽  
Soybean Meal ◽  
Rapeseed Meal ◽  
Nutrient Digestibility ◽  
Control Group ◽  
Feed Conversion ◽  
Weaned Piglets ◽  
Feed Conversion Rate ◽  
Positive Effect

AbstractThe aim of the study was to assess the effect of fermented dried soybean (FSBM) and/or fermented rapeseed meal (FRSM) in diets for weaned piglets on production results, nutrient digestibility, gastrointestinal tract histology, and the composition of the gut microbiota. Piglets in the control group received standard diets with soybean meal. Animals in all experimental groups received diets in which a portion of the soybean meal was replaced: in group FR—8% FRSM; in group FR/FS—6% FRSM and 2% FSBM; in group FS/FR—2% FRSM and 6% FSBM and in group FS—8% FSBM. The use of 8% FRSM or 6% FRSM and 2% FSBM in the piglet diets had a positive effect on average daily gains. Piglets from the FR and FR/FS groups had the highest feed conversion rate. Group FS/FR and FS piglets had significantly lower mortality and lower incidence of diarrhoea. Piglets fed a diet with the fermented components, in particular with 8% FRSM or 6% FRSM and 2% FSBM, exhibited a positive effect on the microbiological composition and histology of intestines, which resulted in improved nutrient digestibility coefficients (ATTD and AID).

scholarly journals Advancing improvement in riverine water quality caused a non-native fish species invasion and native fish fauna recovery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Głowacki ◽  
Andrzej Kruk ◽  
Tadeusz Penczak
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Native Species ◽  
Interference Competition ◽  
Fish Fauna ◽  
Species Traits ◽  
Native Fish ◽  
Biological Degradation ◽  
Species Invasion ◽  
Prussian Carp

AbstractThe knowledge of biotic and abiotic drivers that put non-native invasive fishes at a disadvantage to native ones is necessary for suppressing invasions, but the knowledge is scarce, particularly when abiotic changes are fast. In this study, we increased this knowledge by an analysis of the biomass of most harmful Prussian carp Carassius gibelio in a river reviving from biological degradation. The species' invasion followed by the invasion's reversal occurred over only two decades and were documented by frequent monitoring of fish biomass and water quality. An initial moderate improvement in water quality was an environmental filter that enabled Prussian carp’s invasion but prevented the expansion of other species. A later substantial improvement stimulated native species’ colonization of the river, and made one rheophil, ide Leuciscus idus, a significant Prussian carp’s replacer. The redundancy analysis (RDA) of the dependence of changes in the biomass of fish species on water quality factors indicated that Prussian carp and ide responded in a significantly opposite way to changes in water quality in the river over the study period. However, the dependence of Prussian carp biomass on ide biomass, as indicated by regression analysis and analysis of species traits, suggests that the ecomorphological similarity of both species might have produced interference competition that contributed to Prussian carp’s decline.

scholarly journals Enterococcus faecium PNC01 isolated from the intestinal mucosa of chicken as an alternative for antibiotics to reduce feed conversion rate in broiler chickens

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yang He ◽  
Xuan Liu ◽  
Yuanyang Dong ◽  
Jiaqi Lei ◽  
Koichi Ito ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Mucosa ◽  
Conversion Rate ◽  
Broiler Chickens ◽  
Intestinal Epithelial Cells ◽  
Relative Length ◽  
Intestinal Epithelial ◽  
Feed Conversion ◽  
Broiler Production ◽  
Feed Conversion Rate

Abstract Background The development and utilization of probiotics had many environmental benefits for replacing antibiotics in animal production. Bacteria in the intestinal mucosa have better adhesion to the host intestinal epithelial cells compared to bacteria in the intestinal contents. In this study, lactic acid bacteria were isolated from the intestinal mucosa of broiler chickens and investigated as the substitution to antibiotic in broiler production. Results In addition to acid resistance, high temperature resistance, antimicrobial sensitivity tests, and intestinal epithelial cell adhesion, Enterococcus faecium PNC01 (E. faecium PNC01) was showed to be non-cytotoxic to epithelial cells. Draft genome sequence of E. faecium PNC01 predicted that it synthesized bacteriocin to perform probiotic functions and bacteriocin activity assay showed it inhibited Salmonella typhimurium from invading intestinal epithelial cells. Diet supplemented with E. faecium PNC01 increased the ileal villus height and crypt depth in broiler chickens, reduced the relative length of the cecum at day 21, and reduced the relative length of jejunum and ileum at day 42. Diet supplemented with E. faecium PNC01 increased the relative abundance of Firmicutes and Lactobacillus, decreased the relative abundance of Bacteroides in the cecal microbiota. Conclusion E. faecium PNC01 replaced antibiotics to reduce the feed conversion rate. Furthermore, E. faecium PNC01 improved intestinal morphology and altered the composition of microbiota in the cecum to reduce feed conversion rate. Thus, it can be used as an alternative for antibiotics in broiler production to avoid the adverse impact of antibiotics by altering the gut microbiota. Graphic Abstract

Immune response of Salmo salar (exotic fish) and Eleginops maclovinus (native fish) during Francisella noatunensis horizontal transference

Aquaculture ◽  
2021 ◽  
pp. 737796
Author(s):  
Carolina Vargas-Lagos ◽  
Danixa Martínez ◽  
José Luis Muñoz ◽  
Ricardo Enríquez ◽  
Francisco Morera ◽  
...  
Keyword(s):  
Immune Response ◽  
Salmo Salar ◽  
Native Fish ◽  
Exotic Fish ◽  
Eleginops Maclovinus

Performance of the house cricket (Acheta domesticus) on by-product diets in small-scale production

2021 ◽  
pp. 1-6
Author(s):  
J.M. Sorjonen ◽  
M. Karhapää ◽  
S. Holm ◽  
A. Valtonen ◽  
H. Roininen
Keyword(s):  
Conversion Rate ◽  
Development Time ◽  
Acheta Domesticus ◽  
Small Scale ◽  
Scale Production ◽  
Feed Conversion ◽  
House Cricket ◽  
Current Production ◽  
Feed Conversion Rate ◽  
By Products

As insect farming is becoming more popular in Europe and in the US, the use of food industry by-products in insects’ feed is drawing more attention. However, it is still unclear how to maximise the use of by-products in the feeds while meeting the nutritional requirements and maintaining profitable rearing yields with the current production technology. In this study, we conducted an experiment in Finnish small-scale cricket farming and laboratory conditions to determine whether five diet treatments, including by-product diets with barley mash and turnip rape, modify the overall fresh yield (kg), development time and feed conversion rate of the house crickets (Acheta domesticus). We discovered that the diets differed in the overall fresh cricket yield (kg) but not in the development time or the feed conversion rate of the crickets. The diets with a high proportion of by-product decreased the price of the feed but at the same time reduced the yield. Based on our results, complex by-product diets with the by-product proportion of 20-41% are the most suitable for house cricket rearing.

scholarly journals Research on the Influence of the Light and Sexing on Growth Performance and Slaughter Results at Young Quails from Mixed Baloteşti Population of Eggs-Meat

2017 ◽  
Vol 74 (1) ◽  
pp. 15
Author(s):  
Lucian IONITA ◽  
Elena POPESCU-MICLOSANU ◽  
George NICA ◽  
Cornel Octavian PANA
Keyword(s):  
Weight Gain ◽  
Growth Performance ◽  
Conversion Rate ◽  
Live Weight ◽  
Control Group ◽  
Average Weight ◽  
Feed Conversion ◽  
Feed Conversion Rate ◽  
Average Weight Gain ◽  
Experimental Group

The purposes of determining the influence of the light and sexing on growth performance and slaughter results atyoung quails from Balotesti population, was organized an experiment on 150 quails, betwen age of 28 and 70 days. The chicks were divided into two groups (control and experimental), and growth and slaughter performance were determined separately by sex. Have studied 2 lighting programs, a program of continous lighting with photoperiod duration of 16 hours (16 L + 8 N, control group) and a program with lighting with asymetric hours intervals with photoperiod duration of 16 hours (10L+2N+6L+6N, experimental group).Males and females from the experimental group were recorded average performance of growth high during the period 28 - 70 days. Live weight at age of 70 days was higher with 7.54 %, average weight gain was higher with 14.86 % and feed conversion rate was lower with 13.51 % at males from experimental group compared to males from the control group. Also, the live weight at the age of 70 days was higher with 18.09 %; average weight gain was higher with 35.12 %, while feed conversion rate was reduced with 30.08 % on females from the experimental group compared to females from the control group.The results of the slaughter at 70 days were superior in the caseof females from the both groups versus males. The average weight of the carcase was higher with 17.53 % in case of the females than that of males from the experimental group, and the carcase yield was 65.37 % at the females and 65.56 % for males. Also, the average weight of the carcase was higher with 5.08 % in case of females compared to that males from the control group, and the carcase yield was 64.20 % to females 66.70 % on males.Superior results recorded in the case of females and males from the experimental group recommended the program of lighting with asymmetric hours intervals in the growth of youth quail. Also, the higher slaughter results recorded in the case of females of the two groups recommended them in the meat production through a broiler of quail that combine advantages in the production of both males and females. 

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