Almaco jack (Seriola rivoliana), also commonly known as kampachi, is a popular commercial teleost that has become increasingly important for aquaculture during the last few decades. In this study, temperature cycling of almaco jack broodstock was conducted to determine its effects on reproductive performance and spawn quality. Before temperature manipulation trials commenced, five spawns (n = 5) were collected in a span of one month to establish baseline values before thermal intervention. Eight spawns (n = 8) post-temperature manipulation were collected and evaluated. Results indicate that spawns from one month post-temperature manipulation had higher average egg quantities compared to pre-temperature manipulation spawns one month prior. Spawn quality was quantified using the following metrics: egg diameter and oil globule diameter (μm); shattered oil globule rate (%); hatch rate (%); and larval survival activity indices (SAI) to determine larval quality. Egg morphometrics did not statistically differ (p < 0.05) between pre- and post-temperature manipulated spawns. However, spawns collected pre-treatment had a statistically lower shattered oil globule rate (13.35 %) than spawns’ post-treatment (34.71 %). SAI of post-treatment spawns were statistically higher (mean 205.38 ± 131.42) then spawns prior to treatment (mean 125.5 ± 63.53). Results indicate that there were some positive correlations between number of spawning events and thermally cycled S. rivoliana broodstock, with temperature manipulated broodstock having more frequent spawning events. Larval SAI analysis indicated positive effects on larval development and quality when brood were placed under reproductive dormancy through thermal “off-season” simulation. This study represents one of the first known trials aimed at improving broodstock performance in this popular marine aquaculture fish species, with results indicating temperature manipulation of almaco jack broodstock has beneficial effects on spawning frequency and embryo quality.
Goldstein, Emma, "The effects of a temperature cycling regime on spawn quality of captive Almaco Jack (Seriola rivoliana) broodstock" (2019). Internship Reports (Restricted). 358.
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