Larval Carp Research Articles

The effect of giving cake artificial feed on the survival rate, and growth of Common carp (Cyprinus carpio) larva in an Installation of Freshwater Culture (IBAT) in Punten, Batu.

Feed is involved in supporting the success of cultivation activities. Thus, an intensive system study is needed to find the right formulation so then these objectives can be achieved optimally. This research was conducted to test the optimal percentage of Cake artificial feed on the survival rate and growth of Common carp (Cyprinus carpio) larva and its relationship to reducing the cost of feeding to a minimum. The Cake artificial feed was given twice a day; morning and afternoon. The results of the Cake artificial feeding on the larval Common carp showed there to be no significantly differencein comparison with the administration of natural feed (Artemia sp.). The effect produced by the Cake artificial feeding on the growth of the larval carp was that SGR was 0.22±0.005 gr/day, FCR was 1.7±0,00 and the survival rate (SR) was 45±0,00 percent. The water quality parameters were measured during the research, including dissolved oxygen (DO) at 5.01 to 6.38 mg/L, pH ranging from 6.7 - 7.5 and an average water temperature of 24.5°C. In conclusion, Cake is not recommended to be given to the larval Common carp as an alternative to natural feed.

Limnology of four saline lakes in western Victoria, Australia: II. Biological parameters

Major biological parameters of four permanent (Lake Colac, Modewarre, Bolac and Tooliorook), shallow and slightly saline lakes in the volcanic plains of western Victoria, Australia recorded bi-monthly between November 1999–September 2001 are described. Chlorophyll a concentration ranged from 3–29 μg l −1 with peaks in autumn. Phytoplankton taxa recorded were diverse, with Chlorophyta and Bacillariophyta being common. Cyanobacterial blooms were recorded mostly in summer. Zooplankton abundance in the lakes ranged from 12–368 individuals per litre. Rotifera dominated Lake Bolac, Copepoda dominated Lake Modewarre and they co-dominated Lake Colac and Tooliorook. Zooplankton interactions with phytoplankton suggest that simple predator-prey relationships cannot fully explain the trends exhibited and that a more complex model was acting to regulate algal biomass. A decline in the abundance of zooplankton in summer in Lake Modewarre was attributed to predation by high number of exotic larval carp at that time of the year. A total of 25 benthic macroinvertebrate taxa were recorded from Lake Colac, 30 from Modewarre, 22 from Bolac and 35 from Tooliorook. Twenty-one of the 45 taxa identified occurred in at least three lakes. Nine of the 12 taxa that occurred in only one lake were from Lake Tooliorook. Simpson's diversity index was low in Lake Bolac when compared to other three lakes. Lake Modewarre had more benthic individuals (3246 Ind m −2) than other three lakes (range 624–1397 Ind m −2). The combined contribution of Ostracoda, Amphipoda and Gastropoda dominated the benthos in all the lakes throughout the study period. Macroinvertebrate taxa richness was higher in the present study lakes than recorded from the lakes in the region. Frequency of sampling and number of sampling sites seemed more important in determining species richness than the size and shallowness of the lakes.

Foraging patterns of juvenile walleye (Stizostedion vitreum) in a system consisting of a single predator and two prey species: testing model predictions

We tested the hypothesis that the presence of a large number of energetically inferior prey (Daphnia pulex) in the environment with energetically superior prey (larval carp, Cyprinus carpio) interferes with foraging efficiency of juvenile walleye (Stizostedion vitreum). We monitored functional responses of juvenile walleye feeding on larval carp alone or in combination with D. pulex. When walleye were offered larval carp at increasing densities (10, 20, 50, and 100 individuals/30-L aquarium), they responded in accordance with a type-II functional response in 10-min trials. Walleye captured the maximum number of larval carp when offered a carp density of 20 individuals/aquarium without the daphnids. Further increase in density of larval carp had no effect on walleye foraging rate. The presence of D. pulex (900 individuals/aquarium) suppressed the efficiency of foraging walleye. The predator consistently captured fewer larval carp in all treatments when they were offered together with the daphnids even though walleye continued to select the more profitable larval carp. The negative effect of daphnids on the feeding rate is an example of environmental constraints interfering with optimal foraging models. In this study, walleye appeared to experience a confusion effect caused by the large number of inferior prey. Consequently, the predator could not gain as much energy per unit time when confronted with two prey types as it was when foraging on larval carp alone.

Foraging patterns of juvenile walleye (<i>Stizostedion vitreum</i>) in a system consisting of a single predator and two prey species: testing model predictions

We tested the hypothesis that the presence of a large number of energetically inferior prey (Daphnia pulex) in the environment with energetically superior prey (larval carp, Cyprinus carpio) interf...

Effects of environmental temperature on the development of the myotomal white muscle in larval carp (Cyprinus carpio L.).

A study was conducted on common carp (Cyprinus carpio L.) to determine the effects of environmental temperature experienced by embryos and larvae on the development of myotomal white muscle. Eggs from one female were divided into two groups following fertilisation and incubated at constant pre-hatch temperatures of 18 or 28 degrees C. At hatching, larvae from the 18 degrees C-incubated eggs were divided into two groups and either reared at the same temperature of 18 degrees C ('cold' group) or transferred over a period of 5 days (at 2 degrees C per day) to 28 degrees C ('transferred' group). Larvae hatched from eggs incubated at 28 degrees C were reared at the same temperature of 28 degrees C ('warm' group). Larvae were sampled at two developmental stages (stage 1, inflation of the back chamber of the swimbladder; stage 2, inflation of the front chamber of the swimbladder) and at 26 days post-hatching. The maturation of myotome shape during larval life was studied in parallel with the changes occurring in the organisation of white fibres. At stage 1, the epaxial part of the myotomes surrounding the vent had the shape of lamellae inclined backwards, and only one central layer of white fibres was present. At stage 2, the epaxial part of the myotomes began to acquire a V-shape, which was well developed at 26 days post-hatch. At stage 2 and at 26 days post-hatch, two layers of white fibres were identified: the initial central layer and a second apical layer. These differ in their orientation, the initial central layer being orientated backwards and the apical layer forwards, and in the mean fibre diameter, which is greater in the initial central layer. Studies on the effects of temperature (constant 18 degrees C, constant 28 degrees C, transfer from 18 to 28 degrees C at hatching) were carried out according to both the developmental stage and the length of the larvae. At stage 1, no significant differences were found between the three groups for larval standard length and muscle variables. The number of fibres in one quadrant of epaxial white muscle sectioned at the level of the vent was 100-111. At stage 2, there were significant differences between groups. Larval standard length and mass were higher in the cold group than in the warm group. The transferred larvae were of intermediate standard length but had a significantly higher cross-sectional area of white muscle than either of the other two groups. This increase in surface area was related to a 50 % greater fibre number (233) in the transferred larvae compared with the cold (165) or the warm (152) larvae. The increase in fibre number was more marked for large-diameter ( >20 microm) white fibres located in the initial central fibre layer (+58-72 % in transferred larvae) than in small-diameter ((less than equal to) 10 microm) white fibres mainly located in the apical layer (+18-35 %). In 26 days post-hatch samples, transferred larvae still showed a higher total number of white fibres than warm larvae, but the difference was no longer significant when the total number of white fibres was regressed against larval standard length, suggesting that this stimulation may be temporary.

Comparison of different soybean phospholipidic fractions as dietary supplements for common carp, Cyprinus carpio, larvae

Two experiments were conducted in order to compare the effects of several phospholipid (PL) sources prepared from soybean lecithin on growth and survival of start-feeding carp larvae. Eight diets were tested in each experiment. All diets contained 94% of the same casein–dextrin mixture and 6% of added lipid, consisting of peanut oil alone or supplemented with a PL source. In both experiments, diets supplemented with fractions enriched in phosphatidylinositol (PI) resulted in the highest survival (95% after 25 and 31 days, respectively). Addition of phosphatidylcholine (PC) allowed high initial growth rates during the first week of feeding, similar to or higher than those obtained with PI, but induced a peak of mortality afterwards and, in the first experiment, a high frequency of deformed fish. Larvae fed PC-enriched diets started to die at a larger size than larvae fed PL-deficient diets. Other tested fractions with phosphatidylethanolamine, phosphatidylserine or phosphatidic acid as the major PL class resulted in intermediate results between those given by PI- and PC-rich fractions. Dietary hydrogenated soybean PC resulted in a decreased growth compared to native soybean PC. Soybean lysolecithin was inferior to original lecithin for final larval growth and survival, but was superior to peanut oil without PL. Present results confirm that both the polar head group and the fatty acid composition of the dietary PL may affect their nutritional value for larval carp and suggest distinct requirements for PI and PC.

Endocrine stress response and abnormal development in carp (Cyprinus carpio) larvae after exposure of the embryos to PCB 126

To investigate whether PCB 126 exposure duringembryonic development induces an endocrine stressresponse in larval carp, eggs were exposed,containing 0.01% ethanol (vehicle-control), 10-11,immediately after fertilization, for 48 h to water10-10 or 10-9 mol l-1 PCB in 0.01% ethanol. Eggsincubated in water served as controls. After transferto PCB-free water, mortality, the incidence ofyolk-sac and pe-ricardial oedema, wet and dry weight,rate of skin pigmentation, and whole-body contents ofthe stress hormones ACTH, α-MSH and cortisol weredetermined at 48, 96, 144, 168, 192 and 216 hpost-fertilization. Except for the dry weight, allparameters of animals exposed to 10-10 and 10-9 moll-1 PCB increased in a concentration-related manner.However, these changes became evident only at 144 hpost-fertilization, i.e. after resorption of theyolk-sac. Swelling of the yolk sac and pericardiumoccurred, and whole-body ACTH, α-MSH and cortisollevels increased. Although animals exposed to 10-10and 10-9 mol l-1 PCB displayed stable but elevatedwhole-body ACTH and α-MSH levels until 216 h,whole-body cortisol concentrations gradually decreasedfrom 168 h post-fertilization, and were significantlybelow control values at 216 h post-fertilization.Exposure of the carp embryos to 10-11 mol l-1 PCB only increased whole-body α-MSH levels. Increased whole-body ACTH and cortisol levels indicate that PCBinduces a stress response in carp larvae, possiblymediated by a disturbed hydromineral balance (oedema).We further suggest that the PCB-stimulated bodypigmentation is mediated by a stimulation of α-MSHsecretion.

Stimulation of gonadal and germ cell development in larval and juvenile carp (Cyprinus carpio L.) by homologous pituitary extract

The data presented show that in larval carp, gonadal size has increased distinctly after treatment with homologous pituitary extract (PE). Moreover, the precocious onset of primordial germ cell proliferation and of sex differentiation into male and female gonads was induced. Body weight of treated and control specimens did not differ significantly from each other throughout the experiment. Treatment of juvenile carp with homologous PE led also to an increase in gonadal size without concomitant increase in body weight. Induction of precocious spermatogenesis was observed too. GTH-levels in control and PE-treated carp were monitored by means of a homologous radioimmunoassay, showing that in PE-treated carp the GTH-level was distinctly elevated. The possible role of pituitary hormones in larval and juvenile gonadal development is discussed.

Strategies and Tactics for Larval Culture of Commercially Important Carp

This paper reviews state-of-the-art techniques for culture of larval common carp, Cyprinus carpio, silver carp, Hypophthalmichthys molitrix, bighead carp, H. nobilis, and grass carp, Crenopharyngodon idella. Water temperature, food, and predation are important factors influencing larval survival and growth. Lower and upper lethal temperatures range from 3 to 44°C. Optimum growth temperatures range from 38 to 40°C. Lethal and optimum temperatures vary with acclimation temperature, fish age, and development stage of fish. Water temperatures are close to optimum for larval culture in tropical regions but are often too low in temperate climates. Intensive culture in temperature-controlled systems is important in temperate climates. The first food eaten by larvae in ponds consists mainly of protozoa, rotifers, and copepod nauplii. As fhe larvae grow, they quickly shift to larger food items, including cladocera and insect larvae. Management practices to enhance natural food development in earthen ponds include ...

Fluctuation in sex steroids and sex steroid-binding protein during the development and annual cycle of the male common carp, Cyprinus carpio

1. 1. Sex steroid concentrations increased during the spawning season in the juvenile and adult male common carp. 2. 2. High levels of plasma sex steroids also were found during the non-spawning season in juvenile fish. 3. 3. No correlation between plasma sex steroid concentrations and SBP binding levels was found in the course of development and annual cycle of male carp. 4. 4. The detection of T concentrations in larval carp occurred earlier than that of T-binding level.

Do carp larvae require vitamin C?

Two experiments were conducted on common carp ( Cyprinus carpio L.) larvae and juveniles. In the first, larvae were fed experimental flaked diets during an initial period of 11 days at a water temperature of 26°C. Different diets based on yeast and liver resulted in insignificant differences in individual body weight of fish which also were significantly smaller (6.5–8.8 mg) than fish fed live Artemia nauplii (33.2 mg). Fish fed dry diets displayed significantly higher mortality (7.8–56.2%) than fish fed live food (0.6%), the former groups showing signs of vitamin deficiency manifested by caudal fin erosion and deformation of gill arches. Total ascorbate and dehydroascorbate were analysed in both fish and diets. Total ascorbate concentrations in whole fish were significantly lower in the groups fed dry diets (16.5–36.9 μg g −1 wet weight) than in the groups fed Artemia (101.1 μg g −1). On average, dehydroascorbate constituted 74% and 55.2% of total ascorbate in fish fed dry diets and live Artemia, respectively. In the second experiment 33-mg juveniles previously fed Artemia were offered the same dry diets and this treatment resulted in 5.5-fold body weight increments within 16 days. Total ascorbate content in fish varied from 39.3 to 62.3 μg g −1, but the reduced ascorbic acid constituted a much higher proportion (37.8–52.5%) than in larval carp. It seems that common carp larvae require vitamin C, which is the opposite of what has been reported for juveniles and adults of this species.

Relation between Aiming and Catch Success in Larval Fishes

The actual attack of prey by common carp (Cyprinus carpio) and northern pike (Esox lucius) larvae, lasting 5–20 ms, was described using high-speed cinematography showing synchronous lateral and ventral views. The accuracy of aiming at the prey was measured. A model comparing the ratio mouth radius/aiming inaccuracy to catch success of stationary prey accurately predicted catch success for larval carp feeding on Artemia nauplii and for larval pike feeding on Daphnia. The increase in catch success during ontogeny was caused by an increase in the ratio mouth radius/aiming inaccuracy. Maximal suction velocity in the water flow created by pike larvae (14 mm standard length) was 0.84 m/s, much higher than the escape velocities of even calanoid copepods. Nevertheless, even Daphnia could sometimes escape the suction flow by jumping away. The relative importance of aiming and speed of attack on catch success depended on prey species. Prey size seemed unimportant in determining catch success.

The energetics of feeding strikes in larval carp, Cyprinus carpio

The prey intake of larval carp is described from high‐speed (200–1250 frames s−1) films with synchronous lateral and ventral views. Even in first‐feeding carp larvae, the operculars are functional in sealing effectively the opercular slit until the moment of prey intake, and the maxillaries close off the corners of the mouth, preventing leak flow. In reducing the distance between larva and prey during attack, the relative importance of sucking the prey towards the mouth and swimming forward is variable; overall they are about equally important. The volume and the velocity of the water sucked into the mouth cavity during prey uptake are calculated. The energy costs of suction, i.e., accelerating the water sucked into the mouth cavity, during prey intake are estimated from these values. The energy costs of suction and swimming are in the same order of magnitude. Together they form only a fraction of 1% of the energetic content of the prey, so considerations about energy expenditure seem unimportant in a strategy to optimize the prey attack. During searching, however, they will be important. Power requirements during attack may also be important.

International study on Artemia XXIV. Cold storage of live Artemia nauplii from various geographical sources: Potentials and limits in aquaculture

Freshly-hatched Artemia nauplii from various geographical sources survived storage in a refrigerator (2–4°C) at densities of 2000 per ml and above. Except for Artemia from Chaplin Lake and Buenos Aires, naupliar viability was very high even after 48 h storage, and did not decrease significantly after a 24 h post-storage transfer to 25°C. Neither the naupliar dry weight nor biochemical composition changed significantly during refrigeration for most strains tested. Comparative culture-tests with stored and freshly-hatched nauplii as food for juvenile marine mysids Mysidopsis bahia M. and larval carp Cyprinus carpio L. revealed similar production performances.

Predicting long-term toxicity by subacute screening of pesticides with larvae and early juveniles of four species of freshwater major carp

The present study was designed to determine the 96-hr TL 50 and maximum acceptable toxicant concentration (MATC) of chlordane (organochlorine), Meta-Systox (organophosphate), and Sevin or carbaryl (carbamate) for larvae of four species of freshwater major carp, viz., Labeo rohita, Cirrhina mrigala, Cyprinus carpio, and Catla catla. The 30-day MATC values for each of the four larval carp were found to range from 0.42 to 0.50 μg/liter for chlordane, 40 to 50 μg/liter for Meta-Systox, and 52 to 78 μg/liter for Sevin, respectively, except for Cirrhina mrigala for which the MATC was found to be 30–40 μg/liter for Meta-Systox. Based on the 96-hr TL 50 and MATC so obtained, application factors for each pesticide and for each species were determined which can be utilized for setting water quality standards.