Stereological point-counting; an accurate method for assessing ovarian function in tilapia

Reproductive strategies of the marine fishes from the southwest Atlantic Ocean: an application of histological and image processing techniques

“…In general, the K estimated for S. brasiliensis and S. rastrifer were in agreement with those reported for Tilapia zilli (Cichlidae), Thunnus thynnus (Scombridae) and Sprattus sprattus balticus (Clupeidae) by Coward and Bromage (2002), Aragón et al (2010) and Haslob et al (2013), respectively. However, the low values of β (1.16-1.40) reveal that the shrinkage rate of the oocytes in the histological sections of both species was less than those reported by Emerson et al (1990), Medina et al (2002) and Aragón et al (2010) (β, 1.42-1.56).…”

“…This method takes into account the oocyte shape (β) and size distribution (K) (EMERSON et al, 1990). Both coefficients depend on the oocyte development stage: β-values have been ranged from 1.00 to 1.46 and K from 0.85 to 1.56 (EMERSON et al, 1990;COWARD;BROMAGE, 2002;MEDINA et al, 2002;ARAGÓN et al, 2010;HASLOB et al, 2013). In general, the values of β and K found in the present study lie within the range reported previously.…”

“…So far, the model-based stereology is the most common procedure to estimate the number of oocytes in fish (GANIAS et al, 2014). This includes oocytes in primary growth, vitellogenesis and atresia, as well as post-ovulatory follicles (ISAAC-NAHUM et al, 1988;GREER WALKER et al, 1994;WÖHLER, 1994;BROMLEY et al, 2000;COWARD;BROMAGE, 2002;MEDINA et al, 2002;COOPER et al, 2005;MEDINA et al, 2007;ALONSO-FERNÁNDEZ et al, 2008;SABER et al, 2011;HASLOB et al, 2013;GARCÍA-SEOANE et al, 2014;KNAPP et al, 2014;NEVES et al, 2014;VILLEGAS-RÍOS et al, 2014). Although, it should not be used to count cells of irregular shape and/or highly variable size, e.g.…”

“…Thus, stereological methods have been widely applied in fishery science as an accurate tool for estimating the number of vitellogenic oocytes/ fecundity from ovarian histological preparations (COWARD;BROMAGE, 2002;MEDINA et al, 2007).…”

“…The use of histological images and stereological methods has been recently and successfully applied to assessing the reproductive parameters for many fish species around the world (MEDINA et al, 2002;COWARD;BROMAGE, 2002;KJESBU et al, 2010). Thus, the aim of this study was to investigate, for the first time, the reproductive strategy of P. brasiliensis using histology and advanced image processing techniques to estimate the standing stock of the most advanced yolked oocytes and batch fecundity of this species.…”