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

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

Proteomic analysis of pikeperch seminal plasma provides novel insight into the testicular development of domesticated fish stocks

Control of the reproduction of domesticated stocks is considered a prerequisite for aquaculture development of pikeperch. However, knowledge about the physiology of the captive pikeperch male reproductive system and the biology of semen is very limited, especially regarding protein characteristics. The aims of our study were to characterize pikeperch sperm quantity and quality parameters and to analyze changes in the proteome of the same males spawned for the first and second times. Moreover, attempts were made to generate the first proteomic library of seminal plasma proteins. Semen collected during the first spawning season were was characterized by lower sperm concentration and volume than for the second season. Using mass spectrometry-based label-free quantitative proteomics, we identified 850 proteins in the seminal plasma of pikeperch from both spawning seasons, and 65 seminal proteins were found to be differentially abundant between the first and second spawning seasons. The majority of differentially abundant proteins were involved in stress and immune responses, developmental processes, cofactor metabolic processes, proteolysis, cellular oxidant detoxification and organization of the extracellular matrix (ECM). In addition, several proteins unique to pikeperch seminal plasma were identified, including antifreeze proteins, hibernation-specific plasma proteins, lectins and vitellogenin. In summary, our results indicate that males that spawned for the first time were characterized by incompletely mature gonads and the expression of proteins associated with the early phase of spermatogenesis and ECM organization. On the other hand, males that spawned for the second time exhibited advanced gonadal maturation and expression of proteins related to the late stage of spermatogenesis and sperm maturation, including regulation of reactive oxygen species generation, bicarbonate production, sperm elongation and separation. The identification of a large number of seminal plasma proteins provides a valuable resource for understanding the functions of seminal plasma and the molecular mechanisms involved in testicular development and maturation in domesticated fish, which is a prerequisite for better control of reproduction in captivity

Twelve new microsatellite loci of Eurasian perch Perca fluviatilis Linnaeus, 1758

The Eurasian perch (Perca fluviatilis Linnaeus, 1758) is native to almost entire Eurasia. For over the last two decades, this species became an important candidate for intensive freshwater aquaculture due to its high consumer’s acceptance and overall market value. Hence, the intensive production of Eurasian perch has increased considerably allowing effective domestication; there is still a need for the development of effective selective breeding programmes allowing its further expansion. This process, in turn, can be significantly facilitated by molecular genetics. The genetic information of Eurasian perch and its populations is limited. Up to date information of regarding genetic diversity of many populations is still missing, including microsatellites for Eurasian perch, which could be useful during the selective breeding programmes allowing parental assignment and/or to follow heritability of desired traits. In this study, we have developed and characterized new polymorphic microsatellites. Subsequently, those 12 markers have been used further to compare two Hungarian and one Polish Eurasian perch populations. The Hungarian stocks had high genetic similarity (with low diversity), as we assumed, while the Polish population differed significantly. All populations deviated significantly from the Hardy–Weinberg equilibrium, and heterozygote deficiency was detected in all, showing the presence of an anthropogenic effect