Fishery biology of the jumbo flying squid &lt;i&gt;Dosidicus gigas&lt;/i&gt; off the Exclusive Economic Zone of Chilean waters

et al. 2010

J. Mar. Biol. Ass.

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The jumbo flying squid, Dosidicus gigas, support an important squid fishery off the Exclusive Economic Zone of Chilean waters. However, we only have limited information about their biology. In this study, age, growth and population structure of D. gigas were studied using statoliths from 533 specimens (386 females and 147 males) randomly sampled in the Chinese squid jigging surveys from 2007 to 2008 off the Exclusive Economic Zone of Chile. Mantle lengths (MLs) of the sample ranged from 206 to 702 mm, and their ages were estimated from 150 to 307 days for females and from 127 to 302 days for males. At least two spawning groups were identified, the main spawning peak tended to occur between August and November (austral spring group), and the secondary peak appeared during March to June (austral autumn group). The ML–age relationship was best modelled by a linear function for the austral spring group and a power function for the austral autumn group, and the body weight (BW)–age relationship was best described by an exponential function for both the groups. Instantaneous relative growth rates and absolute growth rates for ML and BW did not differ significantly between the two groups. The growth rate of D. gigas tended to be high at young stages, and then decreased after the sub-adult stage (>180 days old). This study suggests large spatial and temporal variability in key life history parameters of D. gigas, calling for the collection of more data with fine spatial and temporal scales to further improve our understanding of the fishery biology of D. gigas.

Section: Discussionmentioning

confidence: 99%

Age, growth and population structure of jumbo flying squid, Dosidicus gigas, based on statolith microstructure off the Exclusive Economic Zone of Chilean waters

et al. 2010

J. Mar. Biol. Ass.

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“…Dosidicus gigas is a key species in pelagic ecosystems because of its high abundance and important role in trophic dynamics (Rosas-Luis et al, 2008). This squid species supports important fisheries in four areas: the Gulf of California (Nev arez-Mart ınez et al, 2000;Morales-Boj orquez et al, 2001), the region off the Costa Rica Dome (Ichii et al, 2002), the coastal and oceanic waters of Peru (Taipe et al, 2001;Waluda et al, 2004a;Chen and Zhao, 2006) and within and outside the Chilean Exclusive Economic Zones (EEZ) (Rocha and Vega, 2003;Z uñiga et al, 2008;Liu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Spatial difference in elemental signatures within early ontogenetic statolith for identifying Jumbo flying squid natal origins

2015

Fisheries Oceanography

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Signatures of trace elements and isotopes in the parts of hard structures formed in the early ontogenetic stages can be used as potential natural tags of adult cephalopods to trace their origins. The Jumbo flying squid, Dosidicus gigas, is widely distributed in the eastern Pacific Ocean. Fourteen detected elemental signatures (7Li, 23Na, 24Mg, 39K, 43Ca 55Mn, 59Co, 60Ni, 63Cu, 66Zn, 88Sr, 137Ba, 208Pb and 238U) were determined in the nuclear zone (N), representing the embryonic stage, and the postnuclear zone (PN), representing the paralarval stage of statoliths for adult D. gigas collected off the Costa Rican, Peruvian and Chilean Exclusive Economic Zones (EEZs) using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS). All measured signatures were significantly different between embryonic and paralarval statoliths, except for Sr, Ba and Pb. Over the three regions, a significant difference was found for Na and Ba within embryonic statoliths and Zn and Ba within paralarval statoliths. A high Ba/Ca ratio in statoliths obtained from Costa Rica was because of the prevalence of strong upwelling in the area. Elemental signatures, especially Ba/Ca, in early ontogenetic statoliths could be used as a proxy for distinguishing different geographical groups and identifying natal origins. However, elemental signatures in embryonic statoliths tended to be a better natural tag than those in paralarval statoliths indicating that paralarvae with the same origin had distinct dispersal pathways. Additionally, stepwise discriminant analysis (SDA) showed there were at least two migration‐based groups: ‘northern’ and ‘southern’ in the eastern Pacific Ocean. Overall, the derived results can improve our knowledge of the population structure, connectivity and life history of D. gigas.

“…The jumbo flying squid, Dosidicus gigas , is widely distributed throughout the Eastern Pacific Ocean between 40°N to 45°S (Nigmatullin et al , 2001), and its distribution tends to be associated with the oceanic waters adjacent to upwelling zones (Nesis, 1970; Ehrhardt et al , 1983). Dosidicus gigas fisheries are mainly developed in the Gulf of California (Nevárez-Martínez et al , 2000; Morales-Bojórquez et al , 2001) and the coastal or oceanic waters of Peru (Taipe et al , 2001; Waluda et al , 2004; Chen & Zhao, 2006) and Chile (Rocha & Vega, 2003; Zúñiga et al , 2008; Liu et al , 2010). Off the Costa Rica waters, Japanese commercial jigging vessels started to target the squid during 1997 and 1999 (Ichii et al , 2002).…”

Section: Introductionmentioning

confidence: 99%

“…Many studies have been conducted on fisheries biology of D. gigas in the Gulf of California, off the Peruvian coast (Masuda et al , 1998; Argüelles et al , 2001; Morales-Bojórquez et al , 2001; Nigmatullin et al , 2001), and high seas of the south-east Pacific Ocean (Ye, 2002; Ye & Chen, 2007; Liu et al , 2010; Chen et al , 2011). Three distinct groups were identified for D. gigas based on their differences in size at maturity (Nigmatullin et al , 2001): a small-sized group (mantle length (ML) 140–340 mm for females and 130–260 mm for males, respectively), a medium-sized group (ML 280–600 mm for females and 240–420 mm for males, respectively), and a large-sized group (ML 550–650 to 1000–1200 mm for females and >400–500 mm for males, respectively).…”

Section: Introductionmentioning

confidence: 99%

Age, growth and population structure of jumbo flying squid, Dosidicus gigas, off the Costa Rica Dome

et al. 2012

J. Mar. Biol. Ass.

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Based on the samples collected in Chinese scientific surveys off the Costa Rica Dome from July to August in 2009, statolith microstructure of the jumbo flying squid, Dosidicus gigas, was analysed for studying their age, growth and population structure. Three typical growth zones (postnuclear, dark and peripheral zones), abnormal increments (checks) and aberrant microstructure (additional centre and additional rings) were found in the statoliths examined. Squid sizes ranged from 205 to 429 mm dorsal mantle length (ML) with ages no more than 10 months for females and 8 months for males. Back-calculated hatching dates were from November 2008 to April 2009. Growth in ML was best described by a linear function for both the sexes, while growth in body weight was best quantified by an exponential function for females and a power curve for males. The maximum absolute daily growth rates and instantaneous growth rate in ML were reached during 181–210 and 151–180 days for females and males, respectively. The Costa Rica Dome and its adjacent waters were considered as a potential spawning ground because of presence of not only high proportion of mature squid but also rhynchoteuthion paralarvae, and high primary productivity from the strong upwelling. This study suggests that D. gigas have complicated intra-specific population structure and large spatial variability in the key life history parameters.