Distribution and genetic variability of young-of-the-year greater amberjack (Seriola dumerili) in the East China Sea

Abstract

We examined the distribution and genetic variability of the greater amberjack Seriola dumerili in the East China Sea (ECS) from the mitochondrial DNA (mtDNA) control region of young-of-the-year (YOY) individuals, which may reflect the genetic characteristics of the spawning population. In the years 2016 and 2017, a total of 165 YOY S. dumerili were collected from two different locations in the ECS: the southern part of the ECS, and western Japanese coast. The spawning period was estimated using otolith daily increments from a total of 67 larvae and juveniles collected in the ECS. Results from size and age distribution indicated that S. dumerili spawned near the shelf break region in the southern ECS from January to April. Phylogenetic analysis based on mtDNA sequence data showed no significant genetic differentiation among samples collected from different locations, implying S. dumerili in the ECS is mainly composed of one population. S. dumerili around the Japanese coast may be originated from the southern ECS.

Migration and spawning behavior of the greater amberjack Seriola dumerili in eastern Taiwan

“…Here, we estimated an SETR following the procedure by Kawabe et al (2017). We examined whether the ambient water temperature data gradually rises (i.e., SETR) between the pre-spawning (November to January) and spawning period (February to April: Hasegawa et al, 2020;Hsiao et al, 2016). The days of both the lowest and highest values of temperature (i.e., start and end dates) during the experience of SETR were identified by applying a 30-day moving-average filter to the raw temperature data.…”

“…Detailed life history information is needed to effectively guide the fisheries management of this valuable resource. To date, the available life history data on the greater amberjack have been based almost entirely on assessments of the age, growth, mortality, and prey items of subadults and adults (Andaloro & Pipitone, 1997;Harris et al, 2007;Humphreys, 1980;Manooch & Potts, 1997;Sley et al, 2016;Thompson et al, 1999) and the early life history of juveniles (Deudero et al, 1999;Hasegawa et al, 2020;Hasegawa, Takatsuki, et al, 2017;Hasegawa, Yeh, et al, 2017;Wells & Rooker, 2004). Despite the importance of fish movements and migrations, data on adult greater amberjack are limited (Jackson et al, 2018;Murie et al, 2011).…”

“…Since the greater amberjack distributes all over the world, several different subpopulations are recognized (Gold & Richardson, 1998;Šegvi c-Bubi c et al, 2016). In the ECS, there is no significant genetic differentiation among samples collected from different locations (see Figure 1 of Hasegawa et al, 2020), although there may be at least two subpopulations of greater amberjack in East Asia: the population in the ECS and the population in the coastal waters of Vietnam and Hainan Islands, China (i.e., the South China Sea [SCS]) (Araki et al, 2018). Highly migratory marine teleosts are present throughout large portions of the world's oceans due to their cosmopolitan distributions, and the analyses of the population structure of these circumglobal fishes are complicated by their ubiquity (Carlsson et al, 2004).…”

“…Blue arrow: the path of ocean currents. Pink square: estimated spawning ground of greater amberjack (based on Hasegawa et al, 2020). (b) The distribution of vertical conductivitytemperature-depth (CTD) observations (closed circles) conducted from 2007 to 2018.…”

“…On the other hand, one fishery-independent method to estimate spawning grounds is to collect eggs and larvae (e.g., Schaefer, 2001;Tsukamoto et al, 2011). A study on the distribution of early larvae of amberjack in the ECS using this method suggests that one of the spawning grounds is located around the continental shelf in the southern ECS (Figure 1a) (Hasegawa et al, 2020). However, eggs have never been collected anywhere in or around this putative spawning ground, and so, further work is needed to identify and verify the spawning grounds using alternative approaches.…”