Egg Stickiness Research Articles

The Use of Pine Apple Juice in the Elimination of Egg Stickiness in Catfish (Clarias gariepinus), Reared in a Hatchery, Sebeta, Ethiopia

The Use of Pine Apple Juice in the Elimination of Egg Stickiness in Catfish (Clarias gariepinus), Reared in a Hatchery, Sebeta, Ethiopia

SEM images reveal intraspecific differences in egg surface properties of common nase ( Chondrostoma nasus L.)

Scanning electron microscopy (SEM) has been widely used to describe interspecific differences in egg quality of teleost freshwater fish, but potential intraspecific differences are poorly studied. Eggs of many rheophilic cyprinids are covered with adhesive structures such as attaching villi facilitating egg attachment at substrates of spawning grounds with high currents. Recent findings indicate that the egg quality of the rheophilic cyprinid common nase (Chondrostoma nasus L.), a target species of conservation, differs in the adhesiveness between spawning populations, potentially explaining differences in recruitment success. In this study, a SEM image-based standardized protocol was established to assess egg surface quality of Chondrostoma nasus eggs. Multivariate statistics detected significant differences of egg surface properties among individual females and among three different populations. These differences were mainly attributed to length variability and merging of adhesive villi as well as to coating and filament-like connections of these structures. The findings of this study highlight the need for further investigations to better understand the relationship of egg surface properties, egg stickiness and hatching success to understand the recruitment ecology and performance of early life stages in freshwater fish.

Brief communication: rapid elimination of egg stickiness using sodium hypochlorite in wels catfish Silurus glanis.

The wels catfish Silurus glanis is valuable fish for aquaculture. Its production relies mainly on artificial reproduction. One of the crucial steps determining success of the reproduction is elimination of egg stickiness after fertilization. To date, the catfish egg de-adhesion is usually carried out using proteolytic enzymes. Here, we prove a novel method based on oxidation of the egg surface by means of sodium hypochlorite. An effect of different exposure times and concentrations on the egg adhesiveness and damage was tested in the first trial. The selected concentration of sodium hypochlorite 0.3mg·l-1 with exposure time 40s was used for comparison with the conventical de-adhesion method using alcalase treatment. The fertilization and hatching rates reached very satisfactory outcome in both treatments (98.3 ± 0.7% vs 97.5 ± 2.2% and 86.6 ± 8.3% vs 91.3 ± 8.5% in alcalase- and sodium hypochlorite-treated embryos, respectively) without any statistical differences. Thus, the de-adhesion method using sodium hypochlorite can be recommended as a suitable method for wels catfish eggs. The method is simple, cheap, very fast, and the treated eggs are disinfected.

Rapid de-adhesion of northern pike Esox lucius eggs using sodium hypochlorite.

The elimination of egg stickiness is required for effective artificial reproduction of northern pike, but until now, available methods have required at least 40min. Sodium hypochlorite was tested under laboratory conditions, and exposure to aqueous concentrations of 0.025-0.05% for 40s effectively eliminated stickiness without adverse effects. Fertilization and hatching rates in laboratory trials were similar to those observed in eggs treated with traditional methods using clay or milk for 40 or 60min, respectively, as well as those without treatment. Testing using conventional hatchery incubation techniques did not reveal differences in fertilization rates, while the number of hatched larva was significantly higher in eggs treated with sodium hypochlorite vs. clay. Eggs treated with sodium hypochlorite retained transparency, which facilitated monitoring of embryo development.

Effect of Different Fertilization and Egg De-adhesion Methods on Hatching and Survival of Clarias gariepinus (Burchell 1822) Fry

Egg adhesiveness has been a major problem affecting the hatchability of Clarias gariepinus. The removal of egg stickiness will improve aquaculture production through enhanced hatching rates. However, appropriate media for removal of adhesiveness in Catfish eggs is not yet well established. This study therefore, determine the optimum concentration and rinsing time of powdered milk (PM), Urea (UR) and Tannic acid (TA) for removal of adhesiveness of African catfish eggs and their effect on fertility and hatching success. Milt and eggs obtained from African Catfish broodstock of the same lineage were used for induced breeding following standard procedure. Four hundred fertilized eggs each were rinsed in the three different media at varying concentrations and exposure time using dry and wet fertilization methods. Treatment efficacy was assessed by comparing the percentage of non-stick eggs, fertilization, hatching and survival rate in the treatment groups and the control. Data were subjected to multivariate general linear model and Duncan multiple range tests at α0.05. Under the wet fertilization method eggs exposed to 10 g PM at 20 minutes gave the highest number of free eggs (87.50%) while 6g UR at 5 minutes recorded the lowest (27.09%). In dry method, 14 g PM at 20 minutes recorded the highest number of free eggs (90.00%) whereas, the lowest (47.50%) was recorded in 6 g urea at one minute rinsing time. The highest number of hatchlings for PM, UR and TA were 53.26%, 33.24%, and 13.13%, respectively. The survival rate was high in all treatments except in 1.5 g TA. Eggs treated with PM solution performed best in adhesiveness removal and recorded highest percentage fertilization and hatching rate. However, more studies should be conducted to establish the appropriate media for other culture fish species.

A novel method for rapid elimination of sturgeon egg stickiness using sodium hypochlorite

Reducing egg stickiness is a crucial step in artificial culture of sturgeon eggs, with commonly used methods being time consuming or interfering with hatching. Sodium hypochlorite (SH) at varying concentrations and exposure times was tested on sterlet Acipenser ruthenus eggs, with 0.03% SH for 40s effectively eliminating stickiness without impairment to eggs, embryo development, or hatching when compared with other de-adhesion methods (clay; NaCl, urea, and tannic acid). Field tests using sterlet, Siberian sturgeon Acipenser baerii, and Russian sturgeon Acipenser gueldenstaedtii showed similar numbers of larvae hatched using SH and clay. Immunohistochemistry revealed a protein carbonyl group only on the surface of eggs treated with SH, evidence of oxidation as the mode of action and indicating that oxidation did not affect inner egg layers or cytoplasm. Treatment with SH is a rapid, simple, and inexpensive method for de-adhesion of sturgeon eggs. Statement of relevanceSturgeons represent a valuable group of fish in aquaculture, especially for caviar, but also for meat production. This study describes a novel approach to sturgeon egg de-adhesion involving oxidation of egg surface. The method requires little time, is low cost, and disinfects and softens the egg surface, which facilitates hatching.

Alcalase treatment for elimination of stickiness in pikeperch (Sander luciopercaL.) eggs under controlled conditions

Elimination of egg stickiness is an important factor in artificial reproduction of pikeperch (Sander lucioperca L.). This study was conducted to evaluate the effectiveness of Alcalase enzyme to remove the adhesive layer of pikeperch eggs. The eggs were treated with Alcalase at 0.5, 1.0, 1.5, 2.0 and 5.0 mL L−1 or a milk/talc solution 2 min post insemination. Duration of exposure was 2 min in Alcalase and 60 min in milk/talc. The highest, albeit not significant, hatching rate (85.4%) was found with 1.5 mL L−1 of Alcalase, but hatching rates were similar in 0.5, 1.0 and 2.0 mL L−1. Hatching rates were significantly lower groups treated with 5.0 mL L−1 Alcalase enzyme (56.4%) compared to groups treated with milk powder and talc (61.3%). Nominally complete removal of adhesiveness was observed in 1.5 and 2 mL L−1. All Alcalase treatments led to significantly lower incubation duration compared with the traditional milk/talc treatment. The application of Alcalase successfully eliminated pikeperch egg stickiness in less time than with traditional milk/clay/talc methods.

Effect of MS (Methylated Spirit) as a Disinfectant and Antisticking Agent on Hatchability of Clarias gariepinus Eggs and Survival of the Hatchlings

African catfish Clarias gariepinus brood stocks were bred by normal induced breeding method. After fertilization, the eggs were treated with 0.40%, 0.50% and 0.60% concentration levels of MS (methylated spirit) and a control treatment without MS (0%). The objective was to remove the stickiness of the egg outer vitelline membrane to improve hatchability and survival of the hatchlings. Two batches of the treatments were carried out according to treatment duration of 5 s and 10 s. The eggs hatched normally with the highest hatching percentage of 62.31% in eggs treated with 0.40% MS concentration in 5 s treatment and 61.92% in the same concentration for 10 s. The control treatment of 0.00% MS treatment gave the lowest hatchability of 49.69% at 5 s and 45.71% at 10 s exposure time. Growth performance of the hatchlings improved in eggs treated than those not treated. Those treated had higher weight gain and percentage specific growth rates than those not treated. Percentage survival ranged from 75% to 90 % in both treated and untreated groups. MS can therefore be safely used in fish hatchery to prevent egg stickiness to improve hatchability and larval development.

Egg stickiness in artificial reproduction of sturgeon: an overview

AbstractThe egg structure of sturgeon is complex, with multiple micropyles and an envelope structure different from that of teleosts and other fish groups. In the sturgeon, an adhesive layer in the follicular epithelium is responsible for the egg adhesiveness. This is a problem for artificial reproduction of many fish species, including sturgeon, when a large number of eggs are incubated in hatchery conditions. Although several techniques for removing adhesiveness have been developed and successfully applied to eggs of common carp, tench, pikeperch and European catfish, de‐sticking methods for sturgeon are limited. Proteolytic enzymes have been successfully applied to common carp, tench and African catfish eggs, leading to a hatching rate over 80% following 2‐min treatment. In sturgeon, blue clay is the most commonly used de‐sticking substance. The chemical reactions determining egg adhesiveness in sturgeon are poorly studied, and optimum methods for removing stickiness remain to be developed.

Chorion surface ultrastructure of loach Misgurnus anguillicaudatus: adaptation to the environment and correlation with the reproductive strategy

The ultrastructure of the egg chorion surface in the loach Misgurnus anguillicaudatus was investigated using scanning electron microscopy (SEM). A single micropyle, which belonged to type II, was found at the animal pole of an M. anguillicaudatus egg. Several sinistral grooves which originated at the micropyle probably served for sperm guidance. The egg envelope had numerous pores with bud-like fillings and a regular arrangement like honeycomb. Lots of small knobs were situated on the zona radiata at the vegetal pole. Water contact triggered egg stickiness within about 10 seconds. The egg surface became smooth after treatment with trypsin solution. The features of the micropyle, pores and stickiness were correlated with the reproductive strategy of the loach and are important for egg identification.

Аналіз рибоводно-біологічних результатів роботи з плідниками російського осетра на базі ОРЗ «Лебяжий» (Астраханська обл., Російська Федерація)

Проведено аналіз рибоводно-біологічних результатів, отриманих під час роботи з плідниками російського осетра у 2011 р. на ОРЗ «Лебяжий». У результаті аналізу отримано інформацію про стан запасів осетрових видів у Волго-Каспійському басейні. Наведено порівняльні результати роботи з плідниками російського осетра в період нерестової кампанії, яка проводилась у два тури. Використання синтетичного препарату сурфагон для стимуляції статевої активності плідників забезпечує майже 100% відповідь самок. У результаті проведення нерестової кампанії отримано 170 кг ікри, при цьому середня робоча плодючість самок першого туру складала 198,2 тис. ікринок, а самок другого туру – 184, 6 тис. ікринок, що відповідає нормативам.

The application of tannic acid to the elimination of egg stickiness at varied moments of the egg swelling process in pikeperch,Sander lucioperca(L.)

The aim of this article was to analyse the process of pikeperch, Sander lucioperca, egg swelling and to apply tannic acid to eliminate egg stickiness at different moments of the swelling process on artificially obtained eggs. The first experiment involved observation of egg swelling process and the second determined the effect of temperature (12, 14 and 16°C) on the egg swelling rate. The third experiment involved elimination of egg stickiness in a tannin solution (0.75 g L−1) where eggs were submerged in a solution for 0.5, 1, 2 and 5 min – 5, 10, 15, 20, 25 and 30 min following gamete activation. The results indicate that the pikeperch egg swelling process lasts 30 min. It was found that the temperature did not affect the process duration. The results of the third experiment showed that the effectiveness of tannic acid application in egg stickiness elimination increases with time. The best result was obtained in groups of eggs submerged for 1 and 2 min (86.5% and 80.5% of larvae were obtained respectively) 30 min following the gamete activation. The results presented in this study for the first time indicate the possibility of highly effective procedure of egg stickiness elimination with tannic acid in pikeperch aquaculture.

Evaluación de métodos para la eliminación de la capa adherente de los huevos del botete diana Sphoeroides annulatus (Pisces: Tetraodontidae)

Six different hatching treatments and one control were used to eliminate egg stickiness of fertilized bullseye puffer fish Sphoeroides annulatus eggs in this experiment. Each treatment was carried out in triplicate and the eggs were incubated in fiberglass tanks. A fertilization rate of 96.2% ± 2.4% was obtained and significant differences were observed between treatments. The highest hatching rate occurred at 96.4 ± 2% with the protease enzyme solution whilst the lowest rate was observed in the control (18.8 ± 5.3%). The hatching success of the bullseye puffer fish is significantly improved by eliminating egg adhesion.

Physiological and biochemical investigations on egg stickiness in common carp

The properties and behaviour of common carp, Cyprinus carpio, eggs in water and in ovarian fluids were studied at different temperature, pH, and with divalent cation concentrations. The biochemical composition of zona radiata externa (ZRE) was analyzed qualitatively and quantitatively on amino acids, carbohydrates, uronic acid and sialic acids using chemical assays; on proteins using electrophoresis. Comparative biochemical studies were performed on the chub, Leuciscus cephalus, the vimba, Vimba vimba and the bleak, Chalcalburnus chalcoides. Eggs of common carp became sticky within seconds after mixing with water. Egg stickiness was not affected by water pH in a range of 6–9, by water temperatures between 4 and 30 °C, by divalent cations in concentrations ≤20 mmol/l, and by sodium chloride concentrations ≤50 mmol/l. Our investigations indicated that specific proteins of the cyprinid ovarian fluid are controlling (inhibiting) the initiation of egg stickiness: egg stickiness did not develop as long as the eggs were incubated in ovarian fluid. When however the ovarian fluid proteins were removed from the ovarian fluid by heat treatment, eggs developed stickiness within seconds, like they do in water. Biochemically, the ZRE consisted of nine types of proteins whereby four of them were glycoproteins. Glucose, fructose, galactose, and uronic acids were the major carbohydrates. Treatment of the egg membrane with invertase or amyloglucosidase did not affect the egg stickiness. Treatment with protease prevented stickiness. From these results and from additional histochemical results, we conclude that glycoproteins are likely to be the molecules responsible for stickiness.

Use of Pineapple Juice for Elimination of Egg Stickiness of Common Carp (Cyprinus carpio L.)

Four treatments including three different concentrations of pineapple solution (I %, 3%, 5%) and the traditional method (salt/urea/tannin solutions) were used to eliminate egg stickiness of common carp. With the traditional method, fertilization and hatching rates were 74.5% ± 1.2 and 70.2% ± 1.1, respectively. The highest fertilization rate (89.3% ± 0.7) and hatching rate (86.6% ± 1.4) were found with treatment of 1% pineapple juice solution and was significantly different from those obtained with other treatments (P

Optimization of artificial propagation in European catfish, Silurus glanis L.

The present work optimizes procedures for artificial insemination of European catfish, Silurus glanis L., with goals to increase collection of sperm and hatching rate. We address technical aspects of immobilizing solution (IS), activation solution (AS), process of insemination, activation of gametes and elimination of eggs stickiness with a practical solution for artificial propagation in hatcheries. Spermiation was stimulated and could be sustained over a period of 1 month after weekly carp pituitary (CP) injection of 5 mg kg −1 b.w. Males produced significantly the largest quantity of sperm, 0.12–0.13·10 9 spermatozoa kg −1 b.w., after third and fourth injections. The best IS for sperm was determined as solution containing 170–200 mM NaCl, 30 mM Tris–HCl, pH 7 and activation solution for activation of gametes containing 17 mM NaCl, 5 mM Tris–HCl, pH 7. The ratio of 1:2 rather than ratio of 1:1 in the control batch (volume of activation solution in milliliters/grams of eggs) increased the hatchability up to 68%. The highest hatching success of 82–88% from four individual females were found for sperm number of 800–80,000 spermatozoa egg −1, in comparison to 26% hatching at 80 spermatozoa egg −1. The best time for application of alcalase enzyme for elimination of egg stickiness was 3 min after gamete activation at concentration of 20 ml enzyme l −1 with exposure of 2 min.

Improvement of common carp artificial reproduction using enzyme for elimination of egg stickiness

This study summarizes optimization of techniques for common carp artificial propagation including improvements of activation solution (AS), the process of insemination, and elimination of egg stickiness. The optimum gamete ratio for good fertilization and hatching rate ranged from 8490 to 23 672 spermatozoa per egg, when dechlorinated tap water was used. Optimal ratio between eggs (weight in g) and AS (in ml) was defined as 1:1 to 1:2. Different concentrations of AS such as NaCl from 0 to 34 mM (0–68 mOsmol kg –1) did not change fertilization and hatching rates. An AS adopted for carp spermatozoa (45 mM NaCl, 5 mM KCl, 30 mM Tris–HCl, pH 8) was compared with other saline AS; only the 51 mM (102 mOsmol kg –1) NaCl solution decreased fertilization and hatching rate. The AS containing 20 mM Tris–HCl at pH 9 increased fertilization and hatching rates compared to dechlorinated tap water of pH 7 or to AS of pH 6 and 7. Adhesiveness from the eggs was successfully removed by incubation in Alcalase DX (PLN 04715) using two successive steps with different enzyme concentrations. The first step with an enzyme concentration of 2 ml l –1 was applied from 8 to 20 min after fertilization. Later in a second step, the best time for application of alcalase enzyme at a concentration of 20 ml l –1 was for 45 and 60 s at 20 min after fertilization leading to fertilization and hatching rates of 80–87%. The α-Chymotrypsin (EC 3.4.21.1. Merck) was also found effective for elimination of stickiness. Results with α-Chymotrypsin enzyme indicate that the response to success in elimination of stickiness is highly variable mainly due to differences in the environment, quality of water and carp strains.

Egg incubation time and hatching success in tench Tinca tinca (L.) related to the procedure of egg stickiness elimination

Summary The experiment showed different results after a short (2 min) enzyme alcalase Merck EC 3.4.21.14 (5.0 ml L−1 concentration) treatment of tench eggs in contrast to the traditional methods of eliminating egg stickiness involving milk solution (50 g L−1) treatment for 70 min followed by the addition of a talc suspension (33 g L−1) for 10 min or treatment by fine clay suspension (20 g L−1) for 60 min or talc suspension (33 g L−1) for 80 min. The alcalase enzyme treatment resulted in decreased egg stickiness compared with the conventional milk/clay/talc treatments, indicated by lower duration of egg incubation and higher hatching rates (anova for hatching rate, P < 0.0084). The highest hatching rate (93.2%) was achieved using the enzyme; the lowest (31.3%) was using a talc suspension (control hatching rate was 86.2%). Duration of egg incubation at degree-days (D°) after enzyme treatment (58.6 D°) was about 4–5 h shorter than the classical method using milk solution and talc suspension (63–65 D°). Prolongation in the latter classical method may also be explained by a hardening of the egg envelopes.

Proteolytic enzyme treatment: an improved method for elimination of egg stickiness in tench, Tinca tinca L., in aquaculture

Proteolytic enzyme treatment: an improved method for elimination of egg stickiness in tench, <i>Tinca tinca</i> L., in aquaculture

Enzyme treatment for elimination of egg stickiness in tench (Tinca Tinca L.), European catfish (Silurus Glanis L.) and common carp (Cyprinus Carpio L.)

Enzyme treatment to eliminate egg stickiness in tench, European catfish and common carp was compared with standard methodology in an attempt to decrease time consuming under hatchery conditions. Eggs of tench and E. catfish were exposed to an alcalase enzyme MERCK EC 3.4.21.14 (0.6 AU g−1) solution 3 min after egg fertilization for 2 min. The best enzyme concentration in tench and E. catfish was 10 and 20 ml l−1 of enzyme, respectively. The eggs of c. carp were successfully destickiness with ALCALASE DX (2.5 AU g−1) using two concentration of enzyme (2 ml l−1 and 20 ml l−1) from 8 to 20 min after fertilization.