Age and growth of Ceratoscopelus warmingii (Myctophidae) in the South China Sea based on sagittal otolith microstructure

ABSTRACT

Age and growth of a dominant lanternfish Ceratoscopelus warmingii in the South China Sea were investigated based on sagittal otolith microstructure of juvenile and adult specimens collected in June 2015. The length–weight (L-W) relationship for C. warmingii was W_f= 0.00000814 L^3.1170 (females) and W_m= 0.00001071 L^3.3043 (males), revealing both positive allometric growth and non-significant difference between the sexes. Three distinct zones of the otolith microstructure were depicted, a central zone (CZ), middle zone (MZ) and external zone (EZ). Age was estimated by summing the daily growth increments in otolith sections on the assumption of daily deposition. The von Bertalanffy models of females and males were fitted as L_f = 75.9 [1−exp{−0.0074 (t−14.1)}] and L_m = 65.0[1−exp{−0.0097 (t−7.6)}], respectively. The maximum growth rates estimated were 0.319 mm day⁻¹ for females and 0.345 mm day⁻¹ for males, and thereafter the growth rate decreased with age. The back-calculated hatching date of specimens collected was determined as from August of last year to March of next year with a peak in winter. Theoretical maximum growth of C. warmingii appeared to occur near the metamorphic period.

KEYWORDS:

• Ceratoscopelus warmingii
• age estimation
• otolith microstructure
• South China Sea

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgements

We are very thankful to the three anonymous reviewers and subject editor for their helpful and constructive comments. We thank the crew of the R/V Nan Feng for their support. We thank Liwen Bianji, Edanz Group China (www.liwenbianji.cn/ac), for editing the English text of a draft of this manuscript.

Additional information

Funding

National Natural Science Foundation of China (31902374), Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0605), Guangdong Basic and Applied Basic Research Foundation (2021A1515011025), Financial Fund of the Ministry of Agriculture and Rural Affairs (NFZX2021) and Central Public-interest Scientific Institution Basal Research Fund (2020TD05, 2021SD01).