Kontrolisana reprodukcija smuđa, Sander Lucioperca (l.) – dostignuća i izgledi za budućnost

Smuđ, Sander lucioperka, je vrsta ribe koja ima visoku komercijalnu vrednost na Evropskom tržištu i jedan je od najboljih kandidata za intenzivnu proizvodnju u slatkim vodama. Do sada su se mnogobrojne studije bavile različitim aspektima razmnožavanja smuđa. Ipak, još uvek postoje mnogi aspekti koji nisu proučeni, koji su nejasni i veoma često nepredvidivi. To je ono što čini ovaj deo akvakulture veoma teškim za mnoge odgajivače riba i naučnike. Stoga je i cilj ovog članka da da precizan osvrt na trenutna dostignuća u kontrolisanoj reprodukciji smuđa kao i da ukaže na nove načine istraživanja u ovom polju. Da bi se dao opis trenutnog statusa veštačke reprodukcije smuđa opisani su: trenutno stanje hormnonske stimulacije ovulacije i spermijacije, nova klasifikacija stupnjeva sazrevanja, metod za procenu kvaliteta jaja kao i protokoli za tretman jaja. Još uvek jako malo znamo o nekim aspektima kontrolisane reprodukcije smuđa uprkos veoma intenzivnim istraživanjima. Rezultati objavljeni u poslednje tri godine pokazuju da još mnogo treba da se radi na razmatranju ove faze proizvodnje smuđa u akvakulturi. Jedan od glavnih problema je, još uvek, optimizacija hormonalne stimulacije i mužjaka i ženki. Razvoj protokola za hormnonsku indukciju ovulacije može da prouzrokuje ne samo usklađivanje i predviđanje trenutka ovulacije već i kontrolu nad kvalitetom jaja. Prema najnovijim nalazima efekta hormonske stimulacije i temperature na period latencije može se zaključiti da kombinovana stimulacija temperaturom i hormonskim agentima može da postane dobra metoda u kontroli ovulacije ove vrste. Ipak, potrebno je detaljnije istražiti finalno sazrevanje jajnih ćelija (process koji između ostalog uključuje migraciju vezikula gaminativnih ćelija i njihovu razgradnju [GVBD]) i efekate različitih doza i različitih preparata na datoj temperaturi i uslovima gajenja. Ovaj aspekat je još važniji u gajenim nasadima koji su u potpunosti zavisni od uslova koje obezbeđuju farmeri. Što se tiče daljih istraživanja gajenih nasada potrebno je razviti posebne protokole reprodukcije za sve uslove gajenja. Pored stimulacije ovulacije, pažnju treba posvetiti i stimulaciji spermijacije koja predstavlja veliki problem kod ove vrste (lični podatak). Opšti rezultat reprodukcije smuđa se takođe može poboljšati primenom različitih metoda za in vitro oplođenje. Protokoli za tretman jaja posle oplodjenja takođe treba da se unaprede. Iskustvo nekih naučnika ukazuje na to da su protokoli razvijeni u laboratorijama nedovoljno precizni i manje efekasni u određenim komercijalnim uslovima. Zbog toga je potrebno posebno ispitati transfer metoda razvijenih u laboratorijama na uslove komercijalne proizvodnje

Uso de um dispositivo ultrasonográfico para determinar o sexo e efetuar a biópsia das gônadas da Enguia-Européia Anguilla anguilla

The European eel Anguilla anguilla is a highly important market species which is also increasingly in danger of extinction in Europe. One of the ways of protecting the species in the natural environment, while maintaining its market supply, is its aquaculture, e.g. due to much higher survival rate under controlled conditions than in the wild. However, this can be done only when an effective artificial reproduction biotechnique is developed. The aim of this study was to use an ultrasound device to determine the sex and to perform a biopsy of the gonads, which is a part of complete protocol of eel artificial reproduction. The findings indicate that ultrasonography is highly useful in determining the sex in migrating eel (100% of sureness) and in performing high-precision biopsy of the gonads. The present method gives the possibility to quick determine the maturity of the female gonads. The application of ultrasonography (USG) is totally safe for fish and a portable ultrasound device can be used in both the laboratory and in the field. A Enguia-Européia Anguilla anguilla é uma espécie de grande importância comercial e que apresenta também grande risco de extinção na Europa. Uma das formas para a proteção das espécies em seu ambiente natural e de manter o seu suprimento no comércio é a aquicultura, por exemplo, devido à taxa de sobrevivência em condições controladas ser muito superior a existente em condições naturais. Contudo isto só pode ser obtido quando é desenvolvida uma biotécnica de reprodução artificial eficiente. O presente trabalho foi delineado para utilizar um dispositivo ultrassonográfico a fim de determinar o sexo e de possibilitar a realização de biópsias das gônadas, o que é parte do protocolo complete de reprodução artificial de enguias. As constatações indicaram que a ultrassonografia é muito útil para a determinação do sexo das enguias (100% de exatidão) e também é capaz de possibilitar a realização de uma biópsia das gônadas de alta precisão. O método descrito oferece possibilidades para a rápida determinação da maturidade das gônadas das fêmeas. A aplicação da ultrassonografia é totalmente segura para peixes e o dispositivo portátil de ultrassonografia pode ser utilizado tanto no laboratório como em condições de campo

A Novel Approach for Induced Out-of-season Spawning of Eurasian Perch, Perca fluviatilis

International audienceIn this study, the systematic development of a protocol allowing an effective advanced spawning of wild Eurasian perch with the use of salmon gonadoliberin analogue (sGnRHa) was undertaken. The novel approach used in this study involved the application of a strategy of the repeated administration of sGnRHa (i.e., the hormone was given in two doses: priming and resolving) along with an additional thermal stimulation of ovulation. Additionally, the developed protocol was tested for its suitability in the controlled reproduction of domesticated broodstock. The obtained results suggested that the best interval between the hormonal treatments is 7 days when a water temperature of 10°C is kept constant between the two injections and when the resolving injection is followed by rapid increments of temperature up to 12°C, at which spawning is expected. This study revealed that the most suitable priming dose of sGnRHa was 10 µg kg-1 , at which the highest embryonic survival rates (>80%) an

Paternal identity impacts embryonic development for two species of freshwater fish

Paternal, compared to maternal, contributions were believed to have only a limited influence on embryonic development and larval fitness traits in fishes. Therefore, the perspective of male influence on early life history traits has come under scrutiny. This study was conducted to determine parental effects on the rate of eyed embryos of Ide Leuciscus idus and Northern pike Esox lucius. Five sires and five dams from each species were crossed using a quantitative genetic breeding design and the resulting 25 sib groups of each species were reared to the embryonic eyed stage. We then partition variation in embryonic phenotypic performance to maternal, paternal, and parental interactions using the Restricted Maximum Likelihood (REML) model. Results showed that paternal, maternal, and the paternal × maternal interaction terms were highly significant for both species; clearly demonstrating that certain family combinations were more compatible than others. Paternal effects explained 20.24% of the total variance, which was 2-fold higher than the maternal effects (10.73%) in Ide, while paternal effects explained 18.9% of the total variance, which was 15-fold higher than the maternal effects (1.3%) in Northern pike. Together, these results indicate that male effects are of major importance during embryonic development for these species. Furthermore, this study demonstrates that genetic compatibility between sires and dams plays an important role and needs to be taken into consideration for reproduction of these and likely other economically important fish species

Changes in European eel ovary development and body and ovary chemistry during stimulated maturation under controlled conditions: preliminary data

This study compared changes in the biochemical composition of muscles and ovaries of maturing female European eels during hormonal stimulation with carp pituitary homogenate under controlled conditions and in the development of oocytes. It has been found that differentiation of oocyte size in eel is visible from the beginning of the gamete maturation process. This differentiation increases as gonads grow. Furthermore, oocytes are at different development stages and are still highly differentiated in terms of size during ovulation. Moreover, the biochemical composition of the body and gonads was found to change. During the process of maturation, the relative fat content in the eel body decreases both in the muscles (from 21.99 ± 4.3 to 18.48 ± 3.3 %) and in gonads (from 25.76 ± 2.71 to 15.21 ± 4.7 %), with the changes in ovaries being more rapid. Protein content in muscles also decreased (from 15.98 ± 3.13 to 12.35 ± 1.6 %) during the process of female maturation. Different trends were observed for polyunsaturated fatty acids (EPA and DHA). The total amount of these acids decreased in muscles (P\0.05) but increased in ovaries (P[0.05)

Changes in European eel ovary development and body and ovary chemistry during stimulated maturation under controlled conditions -preliminary data

This study compared changes in the biochemical composition of muscles and ovaries of maturing female European eels during hormonal stimulation with carp pituitary homogenate under controlled conditions and in the development of oocytes. It has been found that differentiation of oocyte size in eel is visible from the beginning of the gamete maturation process. This differentiation increases as gonads grow. Furthermore, oocytes are at different development stages and are still highly differentiated in terms of size during ovulation. Moreover, the biochemical composition of the body and gonads was found to change. During the process of maturation, the relative fat content in the eel body decreases both in the muscles (from 21.99 ± 4.3 to 18.48 ± 3.3 %) and in gonads (from 25.76 ± 2.71 to 15.21 ± 4.7 %), with the changes in ovaries being more rapid. Protein content in muscles also decreased (from 15.98 ± 3.13 to 12.35 ± 1.6 %) during the process of female maturation. Different trends were observed for polyunsaturated fatty acids (EPA and DHA). The total amount of these acids decreased in muscles (P\0.05) but increased in ovaries (P[0.05)

Effect of Hormonal Stimulation on Milt Volume, Number of Sperm, and Sperm Motility in the Crucian Carp, Carassius carassius (L.)

Abstract The effects of three commercial hormonal preparations: carp pituitary extract (CPE), Ovopel, and Ovaprim, on quantitative and qualitative parameters of milt from the crucian carp, Carassius carassius (L.), during the spawning season were examined. Males in the control group were injected with 0.9% NaCl. The total volume of milt (ml), total sperm count (× 10 9 ), and concentration of sperm in milt (× 10 9 /ml) were analyzed. Percent motile sperm, percent sperm with progressive movement, curvilinear velocity (µm/s), straight-linear velocity (µm/s), movement linearity (%), wobbling index (%), amplitude of lateral head displacement (µm), and beat cross frequency (Hz) were determined with a computer-assisted sperm analysis (CASA) system. The volume of milt, sperm count, and lateral head displacement were significantly greater in males receiving the Ovaprim treatment than in males stimulated by CPE, Ovopel, or the control but there were no significant differences in any other characteristic. The IJA appears exclusively as a peer-reviewed on-line open-access journal at http://www.siamb.org.il. To read papers free of charge, please register online at registration form. Sale of IJA papers is strictly forbidden. Sale of IJA papers is strictly forbidden. 2 Cejko et al