ABSTRACT
Length-weight and length-girth relationships (LWR and LGR), relative weight (Wr) and relative condition factor (Krel) of four commercial fish species (Lethrinus nebulosus, Carangoides talamparoides, Lutjanus argentimaculatus and Argyrops spinifer) from northern Persian Gulf (Bushehr coastal waters) were calculated. Samples were collected on monthly basis during December 2006 to June 2008 using pot nets. The LWR had a significant correlation for all species and the exponent b ranged from 2.6657 (L. nebulosus) to 2.8353 (L. argentimaculatus). All length-girth relationships also were highly significant and the exponent b ranged from 0.2776 (L. nebulosus) to 0.3591(A. spinifer). Relative weight ranged from 0.50±0.59 (C. talamparoides) to 1.02±1.35 (L. argentimaculatus). Relative condition factor also ranged from 1.01±0.17 (A. spinifer) to 1.05±0.5 (L. nebulosus). In conclusion, this study provides basic information for fishery biologists and managers in the Persian Gulf.
ABSTRACT
The effectiveness of different cryodevices (open-pulled straw (OPS), electron microscopy grid (EMG), and Cryotop was evaluated for vitrification of immature bovine oocytes. Polar body, metaphase II stage (MII), survivability, and subsequent developmental rates were determined. Only oocytes with four or five layers of cumulus cells were used. Oocytes were equilibrated in two vitrification solutions - 1: 10 percent DMSO + 10 percent ethylene glycol (EG) for 30-45sec and 2: 20 percent DMSO + 20 percent EG +0.5M sucrose for 25sec -, mounted on one of the cryodevices and directly plunged into liquid nitrogen for 10 days. Immature vitrified oocytes using Cryotop showed the highest rates of polar body extrusion (PB) and nuclear maturity (MII); 41 and 58 percent respectively. Vitrified oocytes using OPS and EMG showed 26 and 32 percent; and 35 and 46 percent of PB and MII rates, respectively. The highest survivability resulted from Cryotop and EMG groups and no significant difference was found between them. Vitrified oocytes using Cryotop had the highest cleavage and blastocyst rates. All of the mean rates for vitrified immature oocytes were significantly lower than that of control group (P<0.05). The results of this study showed the superiority of Cryotop device for vitrification of immature bovine oocytes.
Avaliou-se a eficácia de diferentes dispositivos de congelamento (envasamento em palhetas (EP), microscopia eletrônica de grade (MEG) e Cryotop) para vitrificação de ovócitos imaturos de bovinos. Para tal, foram determinados o corpo polar, a metáfase II (MII), a viabilidade e as subsequentes taxas de desenvolvimento. Foram utilizados somente ovócitos com quatro ou cinco camadas de células do cumulus. Os ovócitos foram equilibrados em duas soluções de vitrificação - 1: DMSO (10 por cento) + etilenoglicol (EG; 10 por cento) por 30 a 45 segundos e 2: DMSO (20 por cento) + EG (20 por cento) + sacarose (0,5M) por 25 segundos -, transferidos para os dispositivos de congelamento e mantidos, por 10 dias, em nitrogênio líquido. Imediatamente após serem retirados do nitrogênio, os ovócitos foram removidos dos dispositivos e processados para maturação, fertilização e cultivo in vitro. Os ovócitos vitrificados com o Cryotop apresentaram as maiores taxas de extrusão do corpo polar (CP) e de maturidade nuclear (MII), 41 e 58 por cento, respectivamente. Para os ovócitos vitrificados com EP e MEG, as taxas de CP e as de MII foram, respectivamente, de 26 e 32 por cento e de 35 e 46 por cento. As taxas de viabilidade não diferiram entre os grupos Cryotop e EMG. Os ovócitos vitrificados com Cryotop apresentaram as maiores taxas de clivagem e de blastocisto. Para todas as variáveis estudadas, as taxas para os ovócitos vitrificados foram significativamente menores do que as do grupo-controle (P<0,05). Os resultados deste estudo mostraram a superioridade do dispositivo Cryotop para vitrificação de ovócitos imaturos de bovinos.