The body temperatures (Tb) of nine yellowfin tuna (Thunnus albacares) were monitored while fish swam in a large water tunnel at controlled velocities (U) and ambient temperatures (Ta). Monitoring Tb during step changes in Ta at constant U permitted estimation of the thermal rate coefficient (k), an index of heat transfer. In the yellowfin, k is dependent on both Ta and the direction of the ther...

Tuna fisheries catch over three million tonnes of skipjack tuna (Katsuwonus pelamis) each year, the majority of which come from purse-seine vessels targeting fish associated with man-made fish aggregating devices (FADs). A significant challenge for fisheries management is to maximize the efficiency of skipjack tuna catches whilst minimizing the bycatch of small and immature bigeye (Thunnus obes...

Yellowfin tuna, Thunnus albacares (Bonnaterre, 1788) and bigeye tuna, Thunnus obesus (Lowe, 1839) are two of the most economically important tuna species in the world. However, identification of their juveniles, especially at sizes less than 40 cm, is very difficult, often leading to misidentification and miscalculation of their catch estimates. Here, we applied the mitochondrial DNA control re...

Hyperparameter tuning is one of the most time-consuming steps in machine learning. Adaptive optimizers, like AdaGrad and Adam, reduce this labor by tuning an individual learning rate for each variable. Lately, researchers have shown interest in simpler methods like momentum SGD as they often yield better results. We ask: can simple adaptive methods based on SGD perform well? We show empirically...

Executive summary Indices of catch per unit effort are presented for bigeye and yellowfin tuna in the WCPO from 1952 to 2009, based on analyses of aggregated Japanese distant water longline data. One change was made to the methods for estimating indices of abundance for the bigeye and yellowfin stock assessments, with removal of the targeting indicator based on CPUE of other species. This chang...

Background: The aim of this study was to assess the changes in plasma levels of antioxidant enzymes and melano-macrophage centers (MMCs) in immune tissues as biomarkers of yellowfin seabream (Acanthopagrus latus) exposed to phenanthrene (Phe) for 14 days. Methods: The research was carried out at Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran in Jan 2016. Thirty-si...

Estrogen is an essential hormone for many reproductive and non-reproductive functions. The function of estrogen in the reproductive cycle of seabream (Sparus aurata), a protandrous hermaphrodite teleost fish, is complex but it is understood to be involved in sex inversion, a process that occurs in some individuals during the second reproductive season. Estrogen action is mediated by two estroge...

Behaviour of yellowfin (Thunnus albacares) and bigeye tuna (T. obesus)

Stable isotopes of carbon (δ13C) and oxygen (δ18O) in otolith cores (first 2 mo of age) of young-of-the-year (YOY) yellowfin tuna Thunnus albacares were used as natural tracers to predict the nursery origin of sub-adults (age-1) collected from the Hawaiian Islands. YOY fish were first collected from nurseries throughout the western and central Pacific Ocean (WCPO) to determine whether δ13C and ...

The second session of the Scientific Committee (SC) of the Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean (WCPFC) convened August 7-18, 2006 in Manila, Philippines. The SC’s primary activity is scientific assessment of stock status. At the Manila meeting, reports on the status of bigeye, yellowfin, and albacore tuna stocks...