No abstract

The objective was to evaluate the influence of the timing of hormonal induction, using gonadorelin or common carp pituitary extract (CPE), on the reproductive activity of female Astyanax bimaculatus. Fish (N = 44) were weighed, measured, and acclimatized to experimental conditions with a photoperiod of 12 h:12 h light:dark (L:D) for 10 days. Ovulation was induced with a single dose of CPE (6 mg/kg) or gonadorelin (80 μg/kg), given at 12:00 (halfway through the light phase (LP) or 24:00 (halfway through the dark phase (DP), in a 2 × 2 factorial design. The time of ovulation was calculated in degree hours and daily motor activity was recorded using a photocell. The fish were killed and the liver and gonads were weighed for calculation of gonadosomatic (GSI) and hepatosomatic (HSI) indexes, respectively. Absolute fecundity (AF), absolute fecundity relative to weight (AFRW) and length (AFRL), diameter of oocytes (mM), and percentage of oocytes with the germinal vesicle in a peripheral position (PPGV) were recorded. All females responded (ovulated). The female Astyanax bimaculatus had twilight motor activity rhythm. Females given CPE at 12:00 had a higher (P < 0.05) percentage of oocytes with the germinal vesicle in a peripheral position compared with the group that received gonadorelin in the same period (95 ± 6 vs. 79 ± 21%, mean ± SD). The absolute fecundity relative to weight was higher in groups induced at 12:00, regardless of the hormone used (LP: 805 ± 448 and 700 ± 214, for CPE and gonadorelin, respectively; dark phase: 580 ± 396 and 529 ± 105, P < 0.05). Both times used for hormonal induction with CPE and gonadorelin were suitable for inducing reproduction in lambari, although induction with CPE in LP had the best results.

To investigate the impact of different dietary lipid sources on fillet composition and lipid transport, we conducted a feeding trial and evaluated the proximate composition of muscle tissue, fatty acid profiles, total cholesterol (in muscle and plasma), triglycerides, and lipoprotein concentrations in Nile tilapia, Oreochromis niloticus. Five semi‐purified diets, containing different oils (soybean – SO, corn – CO, linseed – LO, fish – FO, and olive – OO), were supplied to tilapia for 160 d. Fish fed with LO and FO diets had a lower percentage of total lipids in muscle compared with the others (P < 0.05). The highest percentage of protein was found in fish fed with FO diet (P < 0.05). The muscle fatty acid profile was influenced differently by diets (P < 0.05). The group supplemented with SO and CO had a higher concentration of 18:2n‐6, whereas the fish fed with LO diet had a higher level of 18:3n‐3 and those that received the FO diet had more 22:6n‐3 in comparison with those supplemented with vegetable oils. Plasma lipid transport was also affected by the diets: the fish fed with FO diet had higher total cholesterol and high‐density lipoprotein and lower very‐low‐density lipoprotein concentrations (P < 0.05).

SUMMARYCurrently, the storage of fish spermatozoa through cryopreservation is widely used. Although it is of common knowledge that the process of freezing / thawing generates DNA fragmentation of spermatozoa, the consequences of this process on embryonary development are unknown. There is great interest in developing methods for in vitro fertilization for the species Prochilodus lineatus using cryopreserved semen. In this paper we study the embryonic development of this fish, to lay the groundwork for the observation of abnormalities in the development of embryos derived from criopreserved spermatozoa. The eggs produced by this species are translucent and have a large perivitelline space, are of the telolecitic type, and presented meroblastic division during the early stages of development. Although the embrionary development of Prochilodus lineatus (Sábalo) took place in less time compared with Danio rerio (Zebrafish) the embryo goes through very similar stages. During the study it was possible to observe the periods of zygote, cleavage, blastula, gastrula, segmentation and hatching of the larvae of Sábalo. The different stages of development were successfully recorded, especially those after the transition of blastula media (TBM), when the embryo begins to transcribe its own genome. Palabras clave: Prochilodus lineatus, peces, embriones.Key words: Prochilodus lineatus, fish, embryos. INTRODUCCIÓN(Ninhaus-Silveira y col 2006). En Brasil existen pocos estudios acerca del desarrollo embrionario del sábalo El sábalo (Prochilodus lineatus) es un pez de la familia (Prochilodus lineatus). La descripción del desarrollo Prochilodontidae, iliófago, distribuido por todo el sudeste embrionario puede tener innumerables ventajas, como favode Brasil, que migra para desovar durante el período de recer el reconocimiento de los embriones en sus ambientes reproducción (Fowler 1950). Esta es una especie encontrada naturales, permitiendo una mejor evaluación del sitio de por toda la cuenca del Río Paraná-Paraguay y Paraíba y desove de los peces y estudios relativos al crecimiento de tiene gran importancia económica y ecológica entre las la especie en su ambiente natural; también es importante especies nativas de tamaño medio y grande. para la detección de las alteraciones relacionadas con los Existen diversas especies de peces en Brasil que han factores ambientales en las incubadoras, que pueden llevar sido poco exploradas y para muchas de éstas se desconoce a una malformación de las larvas y consecuentemente una el potencial zootécnico. Para obtener éxito en la producmenor productividad (Alves y Moura 1992). Las invesción acuícola se vuelve necesario el conocimiento de las tigaciones relativas al desarrollo embrionario y larval en características morfofisiológicas y conductuales de las peces en cautiverio han sido realizadas principalmente en especies en estudio, siendo por este motivo de vital imespecies de interés comercial (Luz y col 2001, Romagosa portancia el estudio de los primeros días de vida (Pezzato y col 2001). 1997). ...

The objective of this study was to evaluate the addition of IGF-I to pig insemination doses stored at 158C, in conjunction with the addition of different amounts of vitamin E (a-tocopherol). Semen samples (n 5 12) from four boars were treated by the addition of different concentrations of vitamin E, ranging up to 400 mg/ml. Immediately after processing and after the doses had been stored at 158C for 24 or 72 h, samples were warmed at 378C and 30 ng/ml of IGF-I was added. The assessments were made after 10 and 120 min of IGF-I addition. There was a minor effect of the vitamin E added before cooling and IGF-I added after storage on sperm quality. The addition of 400 mg/ml of vitamin E to diluted semen reduced ( P , 0.01) the malondialdehyde (MDA) production in boar semen stored at 158C for 72 h, regardless of the addition of IGF-I as additive during a 120 min incubation period at 378C. In these conditions, IGF-I also reduced ( P , 0.05) the MDA production in semen samples without addition of vitamin E. IGF-I in the presence of vitamin E reduced ( P 5 0.03) the glucose intake in freshly diluted boar semen samples before cooling. It was concluded that the addition of 400 mg/ml of vitamin E reduces the MDA production in boar semen stored at 158C for 72 h, regardless of the presence of IGF-I additive. The addition of IGF-I in doses stored for 72 h with vitamin E ensures higher sperm motility after 120 min of incubation at 378C.