ESTUDO ANATOMOPATOLÓGICO DE ALEVINOS DE JUNDIÁ INFECTADOS EXPERIMENTALMENTE POR Ichthyophtirius multifiliis E SUBMETIDOS A TRATAMENTOS CONVENCIONAIS

The white spot disease is caused by Ichthyophthirius multifiliis (ich), a ciliated parasite characterized by its relatively large size, compared to other protozoans. Ich, one of the most devastating parasites affecting jundia culture, may destroy entire populations within a few hours. This study evaluated the histological effect of ich infection under some conventional treatments on jundia fingerlings. Fifteen fish (3-6 cm) were placed in 21 aquaria (10 L) for 5 days. The following treatments were used: C1: non infected control; C2: infected control; F: formalin (0.2 ml/L); M: malachite green (0.1ml/L); and S: NaCl 1% (10g/L). The treatments were used as 3 baths of 1 h between intervals of 48 h. Total mortality of F fish occurred within 48 h, showing that formalin was toxic to jundia under concentration recommended for parasite treatment of most tropical fish species. The lowest mortality rate (33%) was observed for S fish. The histological evaluation showed that ich caused hyperemia and hyperplasia of gill cells surrounding the parasite. At 96 h, trophozoites were observed with the help of microscope (40x) under the skin of C1 fish. Ich was not visible to the naked eye on C1 fish at the beginning of the experimental period. Tomites, a young stage of ich, burrowed into the skin of jundia, penetrated the subepithelial layer and caused damage. Upper layers of skin were sloughed off within 96 h from fish of all treatments, except S fish. Ich irritates fish tissues, mainly the gill cells, and causes high mortality rate within a very short period of time. Additionally, the employed therapeutic treatments cause adverse changes to different levels of severity, mainly on the gill tissue.A doença dos pontos brancos é causada pelo parasita ciliado Ichthyophthirius multifiliis caracterizado pelo seu tamanho relativamente grande quando comparado a outros protozoários. O ictio é responsável pelas maiores perdas observadas na criação do jundiá, podendo destruir toda a população de um viveiro em poucas horas. O presente estudo avaliou e descreveu as alterações patológicas macro e microscópicas causadas pelo ictio em alevinos de jundiá submetidos a tratamentos terapêuticos convencionais. Quinze peixes (3-6 cm) foram estocados em 21 aquários (10 L) e submetidos por cinco dias aos seguintes tratamentos: C1: controle não infectados; C2: controle infectados; F: formalina comercial (0,2ml/l); M: verde malaquita (0,1ml/l); e S: cloreto de sódio 1% (10g/l). Foram realizados três banhos com duração de uma hora e intervalos de 48 horas. Mortalidade total foi observada nos exemplares expostos a formalina por 48 horas, mostrando que alevinos de jundiá são sensíveis a esse produto na concentração recomendada para a maioria das espécies tropicais. A menor taxa de mortalidade (33%) foi registrada para os peixes submetidos ao sal. As análises histológicas denunciaram a presença de hiperemia e hiperplasia nas células do epitélio branquial próximas ao parasita. No grupo C1 foi registrada a presença de trofozoítos nos peixes coletados em 96 horas, sendo que os parasitas não foram observados naqueles peixes, a olho nu, no início do experimento. Tomitos, a forma jovem do parasita, alojaram-se na pele com localização subepidermal e causando lesões. Foi verificada irritação causada pelo ictio em diferentes níveis e em todos os tratamentos, principalmente nas células do epitélio branquial. Próximo ao final do período experimental foi observada esfoliação da pele de peixes de todos os tratamentos, exceto nos peixes submetidos ao sal comum. A infecção pelo ictio ocorre de forma muito rápida e intensa, causando alterações anatomopatológicas severas no tecido branquial e altas taxas de mortalidade em curto período de tempo. Adicionalmente, os tratamentos terapêuticos empregados causam reações adversas no jundiá em graus variados de severidade, principalmente no tecido branquial

Study of the effects of thermal regime and alternative hormonal treatments on the reproductive performance of European eel males (Anguilla anguilla) during induced sexual maturation

[EN] Since 1960, the European eel (Anguilla anguilla) has suffered a dramatic reduction in natural stocks. Breeding in captivity is considered an alternative, but obtaining high quality sperm seems basic on this regard. The main objective of this study was to assess the effects of three thermal regimes (two of them variable: T10 and T15; and one of them constant: T20) and three hormonal treatments with different hormones (hCG, hCGrec and PSMG) on the induction of maturation in European eel males. In the case of the thermal regimes, our results demonstrated that the onset and progression of spermiation are strongly influenced, and perhaps closely regulated, by water temperature. T20 demonstrated the best results in all the sperm parameters (volume, density, motility, kinetic features, etc.) throughout most weeks of treatment, becoming a reliable and productive method for inducing spermiation in this species. In the case of hormonal treatments, the onset and progression of spermiation in European eel males were influenced by the hormone used. In this respect, hCGrec produced the best results in all the sperm parameters including volume, density, motility, kinetic features, etc., throughout most weeks of treatment, thus becoming an effective alternative treatment to the standard hCG treatment used to induce spermiation in eel species. Moreover, hCGrec gave rise to the best economical profitability, making it possible to obtain good quality sperm samples at a lower price than by using the other two hormonal treatments. © 2012 Elsevier B.V. All rights reserved Guardar / Salir Siguiente >Funded by the European Community's 7th Framework Programme under the Theme 2 "Food, Agriculture and Fisheries, and Biotechnology", grant agreement no. 245257 (PRO-EEL) and Generalitat Valenciana (ACOMP/2012/086). Victor Gallego, Ilaria Mazzeo and M. Carmen Vilchez have predoctoral grants from the Spanish Ministry of Science and Innovation (MICINN), Generalitat Valenciana, and UPV PAID Programme (2011-S2-02-6521), respectively. Paulo C.F. Carneiro had post-doc grants from PAC-EMBRAPA and UPV PAID Programme (PAID-02-11). David S. Penaranda was supported by a contract co-financed by MICINN and UPV (PTA2011-4948-I).Gallego Albiach, V.; Mazzeo, I.; Vilchez Olivencia, MC.; Peñaranda, D.; Carneiro, PCF.; Pérez Igualada, LM.; Asturiano Nemesio, JF. (2012). Study of the effects of thermal regime and alternative hormonal treatments on the reproductive performance of European eel males (Anguilla anguilla) during induced sexual maturation. Aquaculture. 354:7-16. https://doi.org/10.1016/j.aquaculture.2012.04.041S71635

Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software

[EN] The development of powerful computer-assisted sperm analysis software has made kinetic studies of spermatozoa possible. This system has been used and validated for several species, but some technical questions have emerged regarding fish sample evaluations (i.e., frame rate, sperm dilution, chamber model, time of analysis, magnification lens, etc.). In the present study, we have evaluated the effects of different procedural and biological settings with the aim to correctly measure sperm quality parameters of the European eel. The use of different chambers did not affect the sperm motility parameters. However, regarding lens magnification, 10x was the most accurate lens, showing the least variation in the acquired data. Similarly, the frame rate setting resulted in a dramatic effect in some sperm kinetic parameters, primarily in terms of curvilinear velocity; we therefore recommend using the camera's highest available frame rate setting. Finally, the reduction in sperm motility over postactivation times suggests that sperm analysis should be performed within the first 60 seconds after activation of the European eel sperm. In conclusion, some protocol variables of sperm analysis by computer-assisted sperm analysis software can affect the measurement of eel sperm quality parameters, and should be considered before directly comparing results obtained by different laboratories. Moreover, because marine fish species show relatively similar features of sperm kinetic parameters, these results could be considered in the evaluation of the motility of sperm from other fish species. (C) 2013 Elsevier Inc. All rights reserved.This study was funded from the European Community's 7th Framework Programme under the Theme 2 "Food, Agriculture and Fisheries, and Biotechnology," grant agreement 245257 (Pro-Eel), and Generalitat Valenciana (ACOMP/2011/229). D.S.P. and P.C.F.C. have postdoctoral grants from UPV (CE-01-10) and PAC-EMBRAPA, respectively. I.M. and V.G. have predoctoral grants from Generalitat Valenciana and Spanish MICINN, respectively. The authors thank the Proiser R&D, S.L. team, who performed the task of fractioning the original sequences for the experiment described in section 3.2.Gallego Albiach, V.; Carneiro, PCF.; Mazzeo, I.; Vilchez Olivencia, MC.; Peñaranda, D.; Soler, C.; Pérez Igualada, LM.... (2013). Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software. Theriogenology. 79(7):1034-1040. https://doi.org/10.1016/j.theriogenology.2013.01.019S1034104079