title: Optimising reproductive induction in yellowbelly flounder (Rhombosolea leporina): Evaluating GnRHa dosage and non-invasive gonadal assessment

authors: Colthorpe, Adam

subjects: aquaculture

abstract: This study investigates two complementary tools to address reproductive dysfunction in wild-caught yellowbelly flounder (Rhombosolea leporina), a key bottleneck in the species’ aquaculture development. First, the effects of varying doses of gonadotropin-releasing hormone analogue (GnRHa) on ovarian development and expression of gonadal cyp19a1a, a gene encoding aromatase, critical for 17β-estradiol synthesis were quantified at short-term timepoints. A single injection of 50 or 100 µg/kg induced transient upregulation of cyp19a1a by Day 1 post-treatment (log₂ fold-changes of +2.38 and +2.65, respectively), while the 25 µg/kg and control groups showed downregulation (−0.53 and −0.07) relative to Day 0 baselines. However, expression declined significantly in all groups by Day 5, including a drop in the 100 µg/kg group to −0.68 (p = 0.03), indicating a brief stimulatory window likely insufficient to sustain steroidogenic activity or promote meaningful oocyte development. These findings support the need for sustained-release hormone systems or improved broodstock staging to enhance treatment efficacy. 

Second, a novel, non-invasive Visual Gonadosomatic Index (VGSI) was evaluated to minimise handling stress while classifying reproductive condition and suitability for hormone treatment. Two metrics were developed using backlit imaging of the ventral gonads: gonad area relative to body area (Size GSI) and gonad length relative to body length (Length GSI). While neither metric correlated strongly with oocyte diameter or histological stage, Length GSI showed a modest but significant association with oocyte development (R² = 0.1937, p = 0.009), and both indices were positively associated with cyp19a1a expression (Size GSI: R² = 0.5045, p = 0.021; Length GSI: R² = 0.3408, p = 0.076). These results suggest VGSI may provide a coarse proxy for reproductive development, though further refinement and validation are required. 

Together, these findings represent the first report of ovarian cyp19a1a expression in R. leporina and lay the groundwork for integrated hormonal and imaging-based strategies to improve reproductive control in this culturally and economically significant flatfish.

text: Optimising reproductive induction in yellowbelly flounder (Rhombosolea leporina): Evaluating GnRHa dosage and non-invasive gonadal assessment This study investigates two complementary tools to address reproductive dysfunction in wild-caught yellowbelly flounder (Rhombosolea leporina), a key bottleneck in the species’ aquaculture development. First, the effects of varying doses of gonadotropin-releasing hormone analogue (GnRHa) on ovarian development and expression of gonadal cyp19a1a, a gene encoding aromatase, critical for 17β-estradiol synthesis were quantified at short-term timepoints. A single injection of 50 or 100 µg/kg induced transient upregulation of cyp19a1a by Day 1 post-treatment (log₂ fold-changes of +2.38 and +2.65, respectively), while the 25 µg/kg and control groups showed downregulation (−0.53 and −0.07) relative to Day 0 baselines. However, expression declined significantly in all groups by Day 5, including a drop in the 100 µg/kg group to −0.68 (p = 0.03), indicating a brief stimulatory window likely insufficient to sustain steroidogenic activity or promote meaningful oocyte development. These findings support the need for sustained-release hormone systems or improved broodstock staging to enhance treatment efficacy. 

Second, a novel, non-invasive Visual Gonadosomatic Index (VGSI) was evaluated to minimise handling stress while classifying reproductive condition and suitability for hormone treatment. Two metrics were developed using backlit imaging of the ventral gonads: gonad area relative to body area (Size GSI) and gonad length relative to body length (Length GSI). While neither metric correlated strongly with oocyte diameter or histological stage, Length GSI showed a modest but significant association with oocyte development (R² = 0.1937, p = 0.009), and both indices were positively associated with cyp19a1a expression (Size GSI: R² = 0.5045, p = 0.021; Length GSI: R² = 0.3408, p = 0.076). These results suggest VGSI may provide a coarse proxy for reproductive development, though further refinement and validation are required. 

Together, these findings represent the first report of ovarian cyp19a1a expression in R. leporina and lay the groundwork for integrated hormonal and imaging-based strategies to improve reproductive control in this culturally and economically significant flatfish.

year: 2025

title: Sports and Bodies: An exploration of bodily inscription through the practice of sport

authors: Baker, Tegan

subjects: Sports

abstract: Sport is an integral aspect of contemporary society; it is also a political, economic, educational, religious and scientific activity. The body and embodied experiences are central to the practice of sport. This research is concerned with both the embodied nature of sport and the potential for sport to mirror, and channel, discourses from wider society. Drawing from the fields of sports geography, bodily geography, and relevant literature from sports studies, the notion of bodily inscription through sport is the focus of this report. Data was collected through focus groups containing a range of social and amateur sports-people with additional data gained through analysis of sports and fitness magazines. The theoretical framework used to contextualise this data is that of Henning Eichberg’s sports trialectic and the wider concept of body culture. This allows for the mapping of bodily inscription via the different characteristics of sport associated with branches of the trialectic; achievement, fitness and body experience. The work of Eichberg also adds another dimension to this analysis - the comparison between sport, democracy and varying iterations of society. In particular, neo-liberalism which is evident through the dominance of efficiency, competition and individualism in sport, is a potent presence. Through the connection between the ‘obesity epidemic’ and neo-liberalism, an over-riding theme is body weight; the defining inscription of a sporting body as leanness. The dominance of concerns over body weight prompted a revision of Eichberg’s sports trialectic model in an attempt to encompass the role of neo-liberalism and the absence of the heuristic element of body experience.

text: Sports and Bodies: An exploration of bodily inscription through the practice of sport Sport is an integral aspect of contemporary society; it is also a political, economic, educational, religious and scientific activity. The body and embodied experiences are central to the practice of sport. This research is concerned with both the embodied nature of sport and the potential for sport to mirror, and channel, discourses from wider society. Drawing from the fields of sports geography, bodily geography, and relevant literature from sports studies, the notion of bodily inscription through sport is the focus of this report. Data was collected through focus groups containing a range of social and amateur sports-people with additional data gained through analysis of sports and fitness magazines. The theoretical framework used to contextualise this data is that of Henning Eichberg’s sports trialectic and the wider concept of body culture. This allows for the mapping of bodily inscription via the different characteristics of sport associated with branches of the trialectic; achievement, fitness and body experience. The work of Eichberg also adds another dimension to this analysis - the comparison between sport, democracy and varying iterations of society. In particular, neo-liberalism which is evident through the dominance of efficiency, competition and individualism in sport, is a potent presence. Through the connection between the ‘obesity epidemic’ and neo-liberalism, an over-riding theme is body weight; the defining inscription of a sporting body as leanness. The dominance of concerns over body weight prompted a revision of Eichberg’s sports trialectic model in an attempt to encompass the role of neo-liberalism and the absence of the heuristic element of body experience.

year: 2014

title: Evidence for late polynesian colonization of New Zealand: University of Waikato radiocarbon measurements

authors: Hogg, Alan G.

subjects: radiocarbon

abstract: We present radiocarbon determinations for 271 New Zealand archaeological samples measured at the University of Waikato Radiocarbon Dating Laboratory between 1975 and 1995. A discard protocol is applied to the series and the list culled to winnow the acceptable dates from those that may incorporate error. None of the 221 acceptable ¹⁴C determinations older than 600 BP (in the case of terrestrial samples) or 930 BP (in the case of marine and estuarine shell) extends beyond cal AD 1250. This conclusion supports the short chronology model of New Zealand prehistory presented by Anderson (1991).

text: Evidence for late polynesian colonization of New Zealand: University of Waikato radiocarbon measurements We present radiocarbon determinations for 271 New Zealand archaeological samples measured at the University of Waikato Radiocarbon Dating Laboratory between 1975 and 1995. A discard protocol is applied to the series and the list culled to winnow the acceptable dates from those that may incorporate error. None of the 221 acceptable ¹⁴C determinations older than 600 BP (in the case of terrestrial samples) or 930 BP (in the case of marine and estuarine shell) extends beyond cal AD 1250. This conclusion supports the short chronology model of New Zealand prehistory presented by Anderson (1991).

year: 1997