Page 128 - 《水产学报》2025年第11期

赵艺翔，等 水产学报, 2025, 49(11): 119310

Effective fecundity in male Sthenoteuthis oualaniensis in
the Northwest Indian Ocean

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1,2
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ZHAO Yixiang , ZHU Kai , WANG Mengjia , WANG Jiahao , ZHU Wenbin 2,3*
1. Marine and Fishery Institute of Zhejiang Ocean University, Zhoushan 316021, China;
2. Key Laboratory of Sustainable Utilization of Technology Research for Fishery Resources of Zhejiang Province,
Scientific Observing and Experimental Station of Fishery Resources for Key Fishing Grounds,
Ministry of Agriculture and Rural Affairs, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China;
3. Fisheries College of Zhejiang Ocean University, Zhoushan 316021, China

Abstract: Sthenoteuthis oualaniensis is an economically important Cephalopod in the Indian Ocean, which has a large amount
of resources and rapid biological turnover. Fecundity provides important data for reflecting the survival ability of species, popu-
lation reproduction, population biomass and other indicators. Research on fecundity can provide insight into the adaptive char-
acteristics of organisms or populations to survive in the environment. In order to deeply understand the effective fecundity char-
acteristics of male S. oualaniensis in the Northwest Indian Ocean, according to the samples of S. oualaniensis in the Northwest
Indian Ocean from November to December 2021 and from March to May 2022. The data of individual mantle length, body
weight, sexual maturity, gonadal weight, number of spermatophores, length of spermatophores and length of spermatophore
sacs were measured, the effective fecundity characteristics, the changes of spermatophoric sac and spermatophore with gonad
development were analyzed. The results showed that the mantle length of male S. oualaniensis ranged from 127 to 275 mm, and
the body weight ranged from 87.1-606.1 g. The gonad index was 0.20%-2.73%, and the spermatophoric complex index was
0.08%-2.63%. The individual fecundity ranged from 1-220, and the relative fecundity of mantle length ranged from 0.006-
1.073 mm each. The length of spermatophoric sac ranged from 49.32-171.60 mm, and the weight ranged from 0.082-5.141 g.
The length and weight of spermatophoric sac increased with the increment of individual mantle length and body weight. The
length of spermatophore was 5.45-70.99 mm, and the weight of spermatophore was 0.2-19.5 mg, they showed a power function
relationship. The length and weight of spermatophore scaled up with growing carcass length and body weight. The above res-
ults showed that the gonad index and spermatophoric complex index of male S. oualaniensis in the Northwest Indian Ocean
magnified with gonad development. Individual effective fecundity, spermatophoric sac and spermatophore increased with the
development of gonad, and had significant functional relationship with individual carcass length and body weight. This study
provides fundamental data on the reproductive biology of male S. oualaniensis, which is crucial for the assessment and sustain-
able management of this resource in the Northwest Indian Ocean.
Key words: Sthenoteuthis oualaniensis; effective fecundity; reproductive biology; Northwest Indian Ocean
Corresponding author: ZHU Wenbin. E-mail: foolse@126.com
Funding projects: National Key R & D Program of China (2019YFD0901505); Key R & D Program of Zhejiang Province
(2018C02026)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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