Comparative Analysis of Different Fish Polyculture Systems

Alternative species for traditional carp polyculture in southern South America: Initial growing period

<em>Abstract</em>.—Numerous natural resource agency and media reports have alleged that Asian carps were introduced into the wild through escapes from commercial fish farms. This chapter traces the chronology associated with importations of Asian carps to North America and discusses the likeliest pathways of their introduction to the wild. The U.S. Fish and Wildlife Service first imported an Asian carp species, grass carp <em>Ctenopharyngodon idella</em>, in 1963. Since then, state and federal agencies, universities, and private fish farmers have interacted to import Asian carps, to develop production technologies, and to promote their use in both public and private sectors in a number of different states. These importations and stocking, whether in confinement or, in the case of the grass carp, sometimes in open waters, were purposeful and legal. Asian carps were introduced to take advantage of their unique food preferences (planktivory by silver carp <em>Hypophthalmichthys molitrix </em>and bighead carp <em>H. nobilis</em>, herbivory by grass carp, and molluscivory by black carp <em>Mylopharyngodon piceus</em>). The first known accidental release of diploid grass carp was in 1966 by the U.S. Fish and Wildlife Service in Stuttgart, Arkansas. Other early reports of grass carp in the wild were from waters in Alabama, Georgia, and Florida. Grass carp were reported from the wild in 1970, 2 years before the first private hatchery received grass carp. By 1972, grass carp had been stocked in open water systems in 16 different states. Silver carp and bighead carp were first imported purposely by a commercial fish producer in Arkansas in 1973. All silver and bighead carps were transferred to the Arkansas Game and Fish Commission by March 1974 where they first successfully spawned silver carp and bighead carp later that year. The first report of silver carp in the wild was in Arizona in 1972, although strong evidence suggests that this may have been a misidentification, followed by reports in Arkansas in the wild in 1975. The Arkansas report occurred 2 years before bighead carp and silver carp were returned to private hatcheries for commercial production. By 1977, silver carp and bighead carp had been introduced to Alabama, Arizona, Arkansas, Illinois, and Tennessee. Research and stockings of silver carp and bighead carp were conducted by at least six state and federal agencies and three universities in seven states in the 1970s and 1980s. Public-sector agencies, which were successful in encouraging development and use of Asian carps that today are in commercial trade, are the likeliest pathways for the earliest escapes of grass carp, silver carp, and bighead carp.

We studied daily periodicity, taxonomic composition and annual variation of fish larvae abundance from a survey of the Zhaoqing section of the Pearl River over a 3-year period, 2006–2008, and collected 52 species, in eight families and 16 orders. The fish larval samples were numerically dominated by six species, Barbel Chub (Squaliobarbus curriculus) 33.1%, Black Guangdong Bream (Megalobrama hoffmanni) 20.6%, Yellowfin (Xenocypris argentea) 15.4%, Mud Carp (Cirrhina molitorella) 10%, Common Sawbelly (Hemiculter leucisculus) 4.3%, and Freshwater Bream (Parabramis pekinensis) 3.1%. These six species accounted for 86.5% of total numbers. Black Carp (Mylopharyngodon piceus), Grass Carp (Ctenopharyngodon idellus), Silver Carp (Hypophthalmichthys molitrix) and Bighead Carp (Aristichthys nobilis) are four of the most economically important fish species in China, and accounted for approximately 4.6% of the total. When compared with historical records from 1931, there are obvious changes in the fish larvae community. Chinese Sturgeon (Acipenser sinensis), Seasonal Shad (Macrura reevesi) and Long Spiky-head Carp (Luciobrama macrocephalus) populations have disappeared and there are also decreases in several other economically important fish populations. We observed a delay in spawning time of Black Carp, Grass Carp, Silver Carp and Bighead Carp, which may be the result of the hydrological regime change in the Pearl River. We used canonical correspondence analysis (CCA) and cross-covariance function (CCF) to analyze the relationship between fish larvae and environmental variables. Our results clearly show that discharge affects the majority of fish larvae, with the various species having different responses. Larval abundances of 15 species such as Black Carp, Grass Carp, Silver Carp, Bighead Carp, Mud Carp and Black Guangdong Bream are significantly and positively related to the discharge. Other species such as Chinese Noodlefish (Leucosoma chinensis) and Rhinogobius olivaceus are negatively related to the discharge. Abundances of larval Mosquitofish (Gambusia affinis), Common Carp (Cyprinus carpio) and Eleotris oxycephala were not related to the discharge. As most economic fish species are affected by discharge, we also conclude that changes of hydrological regime, mainly caused by river damming, will result in the decline of fisheries resources in the Pearl River. The findings of this study have important implications for our ability to model the responses of fish larvae to environmental flows for the purpose of river regulation.

7 - The Common Carp and Chinese Carps

To increase the maximum productivity is prime aim in fish aquaculture from past few years. The increase in maximum standing crop of a pond depends upon the wider range of available foods in ecological niches from the selection of complementary species growing together. The present work was conducted in an attempt to identify the suitable fish species combinations among Hypophthalmichthys molitrix, Aristichthys nobilis, Ctenopharyngodon idella, Cyprinus carpio with the introduction of Amblypharyngodon mola in the prevalent method of fish polyculture system practiced in Nepal. The experiment was conducted for 120 days, in twelve 100 m2 earthen ponds which comprised the initial growing period of fish. As control, one pond was stocked with a species ratio usually employed in the country; H. molitrix (35 %), A. nobilis (10 %), L. rohita (15 %), C. mrigala (10 %), C. idella, (5 %) and C. carpio (25 %). Treatment 2 was stocked with the H. molitrix, A. nobilis, L. rohita and C. mrigala. Treatment 3 was stocked with the H. molitrix, A. nobilis, L. rohita, C. mrigala and C. idella and Treatment 4 was stocked with the H. molitrix, A. nobilis, L. rohita, C. mrigala and C. idella and C. carpio. Each treatment had three replicates. Carp fishes were stocked with stocking density 15000 ha -1 in all treatments. A. mola was stocked @ 50000 ha-1 in treatments, 2, 3 and 4. No significant correlation was found between the growth rate of fish species and the water quality parameters. The final weight of different species, in different treatments, showed statistical differences. Considering growth parameters, the best result was obtained in treatment 2. A complete exclusion of the A. mola in treatment 1 had no advantage over the other treatments; however, the combination of Hypophthalmichthys molitrix, Aristichthys nobilis, Labeo rohita and Cirrhinus mrigala allowed the introduction of A. mola, with positive effects. In addition, the introduction of A. mola in the polycultures tested had no effect over the other carp species. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 92-102

In situ study on the control of toxic Microcystis blooms using phytoplanktivorous fish in the subtropical Lake Taihu of China: A large fish pen experiment

An experiment was conducted in 12 earthen ponds of 200 m2 at Kathar VDC, Chitwan, Nepal for 270 days to analyze the productivity and nutrient budget in some carp based polyculture systems. The experiment was conducted in a completely randomized design with four treatments in triplicate each: a) Carps only or control (7000 fish/ha) (T1); b) Carps (7000/ha) + tilapia (3000/ha) (T2); c) Carps (7000/ha) + tilapia (3000/ha) + sahar (500/ha) (T3); and d) Carps (7000/ha) + tilapia (3000/ha) + sahar (1000/ha) (T4). Silver carp (Hypophthalmich­thys molitrix), bighead carp (Aristichthys nobilis), common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), rohu (Labeo rohita) and mrigal (Cir­rhinus mrigala) of mean stocking size 3.0, 4.2, 10.0, 18.8, 10.5, 2.2 g, respectively were stocked in all ponds at the ratio of 4:2:1:1:1:1. The mean stocking size of Nile tilapia (Oreochromis niloticus) and sahar (Tor putitora) were 9.7 and 3.4 g, respectively. The ponds were fertilized weekly with urea and di-ammonium phosphate @ 4 g N and 1 g P/m2/day. Fish were fed with locally made pellet feed (20% CP) once in an alternate day at @ 2% body weight. At harvest, the extrapolated fish yield ranged from 1.5 to 1.7 t/ha/year in different treatments, without significant differences among treatments (P>0.05). Inclusion of sahar in Nile tilapia ponds decreased recruits by 63 to 72%. There were no significant differences in water quality parameters among treatments, except dissolved oxygen concentration, which was significantly lower in T1 and T3 than T2 and T4 (p<0.05). Both nitrogen and phosphorous were gained from fish species and lost from soil and water. There were no significant differences in nitrogen and phosphorous contents of all inputs and outputs among treatments. The unaccounted nitrogen and phosphorous loss ranged from 9.8-17.1% and 51.2-64.4%, respectively. The nitrogen and phosphorous required for producing 1 kg fish ranged from 337.5-375.9 g and 130.3-150.9 g, without significant difference among treatments. The nitrogen and phosphorous discharged for producing 1 kg fish ranged from 1.59-4.35 g and 1.6-9.3 g, respectively.DOI: http://dx.doi.org/10.3126/on.v11i2.9535 Our Nature 2013, 11(2): 116-125

Two species of congeneric filter-feeding microphagous carps from Asia, the bighead and the silver carp, were recently introduced to North America and have become highly invasive. These species of carp have similar food habits but the silver carp has the unique habit of jumping when disturbed. Both species have complex but poorly understood social behaviors and while both are thought to aggregate (form groups) and shoal (form tight social groups), this possibility has not yet been examined in these species. The present study examined the grouping tendencies of these species in the laboratory and the effects of fish density and species identity on it. Using nearest neighbor distance (NND) as a metric, we showed that both juvenile bighead and juvenile silver carp grouped (aggregate) strongly (P<0.05) but to different extents, and that fish density had no effect (P>0.05) on this behavior. Within aggregations, bighead carp tended to form a single large shoal while silver carp formed shoals of 2–3 individuals. Further, when tested as mixed-species groups, bighead and silver carp readily shoaled with each other but not with the common carp, which is from Eurasia and a member of another feeding guild. Due to their similar feeding strategies, we speculate that the bighead and silver carp tend to aggregate and shoal to facilitate both their foraging efforts and to avoid predation, while the differences in the size of the shoals they form may seemingly reflect their different anti-predation strategies. These complex shoaling behaviors likely influence Asian carp distribution in rivers, and thus how they might be sampled and managed.

The material for this report was the results of bacteriological examination of fish of various species (silver carp (Carassius gibelio); silver carp (Hypophthalmichthys nobilis); white cupid (Ctenopharyngodon idella); common carp (Cyprinus carpio); rainbow trout (Oncorhynchus mykiss), fry of sturgeon of Lena (Acipenser baeri) and sterlet (Acipenser ruthenus)) and various age groups in 2016–2018. in 7 fish farms in Belarus. As a result of research, 21 species of bacteria have been registered in introduced fish species in pond farms that are potential causative agents of bacterial diseases of introduced fish. Two types of bacteria – Shewanella putrefaciens and Aeromonas hydrophila – are invasive and harm the fish industry. Studies have shown seasonal changes in the frequency of occurrence of Sh. putrefaciens and A. hydrophila in introduced fish. During January-March, the infection of fish with A. hydrophila bacteria was not high, increasing sharply in April-May. In June-July, a decrease is observed, and in August is a sharp decrease in the infection of the internal organs and blood of fish with aeromonads. Bacteria Sh. putrefaciens were found in fish much less frequently than A. hydrophila, however, some seasonal dependence in the change in the frequency of its occurrence in introduced species is observed. The peak of occurrence is in June. The maximum values of the frequency of occurrence of pathogens of bacterial infections were noted for A. hydrophila in April (80.0%), for Sh. putrefaciens – in June (33.0%). It should be noted that the active consumption of mixed fodder and natural feed by the fish leads to the restoration of the body’s immune status after winter.

Purpose. The objective of the paper is to summarise the scientific findings on the maximum lengths and weight of freshwater fishes in trophy catches of Ukrainian anglers based on the author’s materials. Methodology. As a result of many years of studies and observations (2000–2021), the data on the maximum lengths and weights of 18 species of freshwater fishes caught by the Ukrainian anglers were collected. Ichthyological materials taken from the catches were studied, 184 record applications of the “Prydniprovia Fishing Records” contest and the morphobiological parameters of trophy specimens were analysed. The age of the record fish was determined using their scales. The material was processed according to generally accepted ichthyological methods. Systematic names of fish of Ukraine are given according to the scientific papers by Y.V. Movchan and J.S. Nelson et al. The obtained results were compared with the identical morphobiological parameters of freshwater fishes in scientific databases (FishBase, IGFA). Findings. Reliable material on the maximum lengths and weights of 18 species of freshwater fishes of Ukraine was obtained. The maximum lengths and weights of fishes in the Dnipro reservoirs, their subordinate water bodies, ponds and lakes have been identified: grass carp, chub, asp, Prussian carp, common carp, tench, Silver carp, Bighead carp, rudd, silver bream, common bream, roach, bleak, wels catfish, pike, pikeperch, perch, ruffe. It has been shown that the biological parameters of some fishes (chub, bleak, white bream, Prussian carp, bighead carp, wels catfish, perch, pikeperch) exceeded those for these species provided in the scientific reference literature for the fish in Europe and Ukraine in particular. A comparative analysis of the records of Ukrainian anglers and anglers’ world records (IGFA) indicates that the water bodies of Ukraine may be of interest for trophy fishing. It has been proved that the maximum parameters of chub, white bream and asp caught by anglers in Ukraine exceeded the official world records. Originality. For the first time, the scientific findings of the maximum lengths and weights of freshwater fish in trophy catches of anglers of Ukraine for 2000–2021 have been generalised. Practical Value. The study of the qualitative characteristics of recreational fishing in Ukraine is an effective additional tool to obtain scientific knowledge about the fish biology and ecology. The results obtained have an important and diverse practical significance, in particular, they can be used by specialists for further fisheries management, for making decisions on investments in natural resources and the use of ecosystem services, and they can also represent a justification for the development of recreational tourism in Ukraine in the post-war period. Keywords: Ukraine, aquatic bioresources, recreational fishing, amateur anglers, fishing records, maximum size, maximum weight, age of fish.

Fishes utilize several different species-specific reproductive strategies adapted to their environment. Invasive species may display reproductive strategies that allow successful reproduction in varying environments, such as batch and protracted spawning. Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix, referred to as bigheaded carp, are invasive species that have been introduced worldwide. In some invaded ranges, they either have a protracted spawning period and/or spawn multiple times in a season, which can be advantageous in novel environments. Reproductive strategies can vary between river systems or with environmental conditions, and understanding differences in strategies can improve management of bigheaded carp. To determine reproductive strategy, we evaluated the histology of spawning capable ovaries from Silver Carp (n = 58) and Bighead Carp (n = 38) collected during May–September 2016 and June 2017 from Pools 17–20 of the upper Mississippi River (UMR). We found that 87.9% of Silver Carp (n = 51) and 86.8% of Bighead Carp (n = 33) had an ovary that contained primary growth, cortical alveolar, and vitellogenic oocytes simultaneously. Multiple stages of oocytes within an ovary indicated that individuals were capable of spawning multiple times during a single year, and the presence of postovulatory follicle complexes demonstrated that individuals had already spawned while oocytes were still present. Based on histological samples, bigheaded carp appear to be indeterminate batch spawners, with oocytes continuing to develop throughout the spawning period. Silver and Bighead carp in the UMR may exhibit protracted and batch spawning and employ flexible spawning strategies among different river systems, which can increase the probability of successful recruitment in a variable environment.

The primary structures of growth hormones of three cyprinid species: Bighead carp, silver carp, and grass carp

The activities of amylase, α- and β-glucosidase, and β-galactosidase in the tissues of carp, Cyprinus carpio, crucian carp, Carassius carassius, grass carp, Ctenopharyngodon idellus, rainbow trout, Salmo gairdnerii, silver carp, Hypophthalmichthys molitrix, tilapia, Tilapia nilotica, and yellowtail, Seriola quinqueradiata, were investigated to see the relation between the feeding habits and the distribution of the enzymes. The species exhibiting the strongest amylase activity of the digestive tracts is crucian carp followed by grass carp, tilapia, carp, and silver carp. Very weak or negligible activities of amylase are found in the digestive tracts of rainbow trout, eel, and yellowtail. These results may support the concept that the amylase activity of the digestive tracts depends on the feeding habit of fish. The liver and spleen of the herbivorous and the omnivorous also show the strong amylase activities, while the carnivorous does not. The activities of α-glucosidase in the tissues of grass carp, the herbivorous, are much stronger than those of eel, the carnivorous. On the other hand, the apparent correlation between the feeding habits and the activities of β-glucosidase is not found even with the digestive tracts. The activities of β-galactosidase in the digestive tracts are stronger in the herbivorous and the omnivorous (except the carp) than in the carnivorous. The liver, kidney, and spleen have also the high activities of β-galactosidase. The intracellular distribution of β-galactosidase in the tissues of fish were confirmed by the histochemical investigations.

Near infrared reflectance spectroscopy was used to discriminate different species of freshwater fish samples. Samples from seven freshwater fish species of the family Cyprinidae (black carp ( Mylopharyngodon piceus), grass carp ( Ctenopharyngodon idellus), silver carp ( Hypophthalmichthys molitrix), bighead carp ( Aristichthys nobilis), common carp ( Cyprinus carpio), crucian ( Carassius auratus), and bream ( Parabramis pekinensis)) were scanned by near infrared reflectance spectroscopy from 1000 nm to 1799 nm. Linear discriminant analysis models were built for the classification of species. We inspected the effect of partial least square, principal component analysis, competitive adaptive reweighted sampling, and fast Fourier transform on linear discriminant analysis. The results showed that the dimension reduction methods worked very well for this example. Linear discriminant analysis models which were combined with principal component analysis and fast Fourier transform could classify accurately all the samples under multiplicative scatter correction pre-processing. According to the loadings in principal component analysis, spectra wavelengths 1000, 1001, 1154, 1208, 1284, 1288, 1497, 1665, and 1770 nm were selected as effective wavelengths in linear discriminant analysis. The discriminant analysis was simplified by using effective wavelengths as independent variables in a linear discriminant analysis model. This study indicated that linear discriminant analysis combined with near infrared reflectance spectroscopy could be an effective strategy for the classification of freshwater fish species.

IntroductionHeavy metals are ubiquitous environmental pollutants, and fish could be contaminated by these metals, potentially posing a threat to human health through the food chain. Understanding the accumulation of these metals in fish tissues is crucial for assessing the safety of consuming fish products.MethodsIn this study, the distribution of nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in tissues of eight fish species (Ctenopharyngodon idellus, Megalobrama amblycephala, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Carassius auratus, Cyprinus carpio, Culter alburnus, and Lateolabrax japonicas) collected from the Baishazhou market with different trophic levels and habitat preference was investigated using inductively coupled plasma mass spectrometry (ICP-MS). The metal accumulation capacity of different fish tissues and species was assessed, and the metal pollution index (MPI) was calculated to evaluate the extent of metal accumulation ability in each species. Additionally, the health risk assessment was conducted to evaluate the potential threat to human health posed by consuming these fish species.ResultsThe levels of metals exhibited variation among different fish tissues and species, showing an order of Zn &amp;gt; Cu &amp;gt; Ni &amp;gt; Pb &amp;gt; Cd. In terms of tissues, fish head demonstrated a greater capacity for metal accumulation compared to the muscles. Regarding fish species, the extent of accumulation ability varied depending on the specific metal, exhibiting the following order according to MPI: H. molitrix (0.568) &amp;gt; C. auratus (0.508) &amp;gt; M. amblycephala (0.469) &amp;gt; C. idellus (0.336) &amp;gt; C. alburnus (0.315) &amp;gt; C. carpio (0.274) &amp;gt; L. japonicus (0.263) &amp;gt; H. nobilis (0.206). Furthermore, in accordance with the results of health risk assessment, there was no potential health risk associated with the consumption of these fish species, as all target hazard quotient (THQ) values (ranger from not detected to 0.192) were below 1, and the maximum hazard index (HI) value was observed in C. carpio (0.519 for adults, 0.622 for children).ConclusionThe findings of this study demonstrate the distribution of heavy metals in fish tissues and indicate there were no potential health risk associated with consuming these fish bought from the Baishazhou market.