Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea
This study aimed to explore the feasibility of using an upper beak microstructure to estimate the age of purpleback flying squid (<i>Sthenoteuthis oualaniensis</i>). From these microstructures, the age and growth of squid caught from January to March and May to August in 2018, 2019, and...
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MDPI AG
2022-07-01
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| Series: | Fishes |
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| Online Access: | https://www.mdpi.com/2410-3888/7/4/187 |
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| author | Ziyue Chen Huajie Lu Wei Liu Kai Liu Xinjun Chen |
| author_facet | Ziyue Chen Huajie Lu Wei Liu Kai Liu Xinjun Chen |
| author_sort | Ziyue Chen |
| collection | DOAJ |
| description | This study aimed to explore the feasibility of using an upper beak microstructure to estimate the age of purpleback flying squid (<i>Sthenoteuthis oualaniensis</i>). From these microstructures, the age and growth of squid caught from January to March and May to August in 2018, 2019, and 2020 in the waters surrounding the Xisha Islands in the South China Sea were determined. We found three typical growth zones (the hood region, crest region, and axis), abnormal increments (checks), and erosion in the beak examination. The average dorsal mantle length (ML) of males and females was 112.13 (±15.23 mm) and 119.67 mm (±24.50 mm), respectively, and no squid were older than 10 months. The peak hatching dates, according to back calculations, were from October to January of the next year. All sampled squid belonged to the autumn/winter cohort. Significant sex differences were found in the relationship between ML and age in squid with similar growth patterns. Exponential models best described the relationships of ML with age and body weight (BW) for both sexes. However, a linear model best described the relationship between age and upper rostrum length (URL). The maximum absolute daily growth rates (AGR) of BW were reached during days 240–270 for both sexes. The maximum AGRs in ML were reached during days 180–210 and 240–270 for males and females, respectively. The period of 120–150 days (4–5 months) was considered the sub-adult stage of <i>S. oualaniensis</i> in the Xisha Islands waters of the South China Sea. This study confirmed that the beak microstructure provides good age estimates for purpleback flying squid (<i>S. oualaniensis</i>). |
| first_indexed | 2024-03-09T04:27:02Z |
| format | Article |
| id | doaj.art-a29aaaf646424515b2f51f71ff93eb34 |
| institution | Directory Open Access Journal |
| issn | 2410-3888 |
| language | English |
| last_indexed | 2024-03-09T04:27:02Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fishes |
| spelling | doaj.art-a29aaaf646424515b2f51f71ff93eb342023-12-03T13:38:49ZengMDPI AGFishes2410-38882022-07-017418710.3390/fishes7040187Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China SeaZiyue Chen0Huajie Lu1Wei Liu2Kai Liu3Xinjun Chen4College of Marine Sciences, Shanghai Ocean University Shanghai, Shanghai 201306, ChinaCollege of Marine Sciences, Shanghai Ocean University Shanghai, Shanghai 201306, ChinaHainan Academy of Ocean and Fisheries Science, Haikou 570100, ChinaCollege of Marine Sciences, Shanghai Ocean University Shanghai, Shanghai 201306, ChinaCollege of Marine Sciences, Shanghai Ocean University Shanghai, Shanghai 201306, ChinaThis study aimed to explore the feasibility of using an upper beak microstructure to estimate the age of purpleback flying squid (<i>Sthenoteuthis oualaniensis</i>). From these microstructures, the age and growth of squid caught from January to March and May to August in 2018, 2019, and 2020 in the waters surrounding the Xisha Islands in the South China Sea were determined. We found three typical growth zones (the hood region, crest region, and axis), abnormal increments (checks), and erosion in the beak examination. The average dorsal mantle length (ML) of males and females was 112.13 (±15.23 mm) and 119.67 mm (±24.50 mm), respectively, and no squid were older than 10 months. The peak hatching dates, according to back calculations, were from October to January of the next year. All sampled squid belonged to the autumn/winter cohort. Significant sex differences were found in the relationship between ML and age in squid with similar growth patterns. Exponential models best described the relationships of ML with age and body weight (BW) for both sexes. However, a linear model best described the relationship between age and upper rostrum length (URL). The maximum absolute daily growth rates (AGR) of BW were reached during days 240–270 for both sexes. The maximum AGRs in ML were reached during days 180–210 and 240–270 for males and females, respectively. The period of 120–150 days (4–5 months) was considered the sub-adult stage of <i>S. oualaniensis</i> in the Xisha Islands waters of the South China Sea. This study confirmed that the beak microstructure provides good age estimates for purpleback flying squid (<i>S. oualaniensis</i>).https://www.mdpi.com/2410-3888/7/4/187<i>Sthenoteuthis oualaniensis</i>beakagegrowth patternSouth China Sea |
| spellingShingle | Ziyue Chen Huajie Lu Wei Liu Kai Liu Xinjun Chen Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea Fishes <i>Sthenoteuthis oualaniensis</i> beak age growth pattern South China Sea |
| title | Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea |
| title_full | Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea |
| title_fullStr | Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea |
| title_full_unstemmed | Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea |
| title_short | Beak Microstructure Estimates of the Age, Growth, and Population Structure of Purpleback Flying Squid (<i>Sthenoteuthis oualaniensis</i>) in the Xisha Islands Waters of the South China Sea |
| title_sort | beak microstructure estimates of the age growth and population structure of purpleback flying squid i sthenoteuthis oualaniensis i in the xisha islands waters of the south china sea |
| topic | <i>Sthenoteuthis oualaniensis</i> beak age growth pattern South China Sea |
| url | https://www.mdpi.com/2410-3888/7/4/187 |
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