Biological aspects of spawning for assessing the stock size Lucensosergia lucens in the Suruga Bay using the egg production method

2017 Fiscal Year Final Research Report

• Project/Area Number: 26850118
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Aquatic bioproduction science
• Research Institution: Tokai University
• Principal Investigator: Doi Wataru 東海大学, 海洋学部, 准教授 (70456325)
• Research Collaborator: SUZUKI NOBUHIRO 東海大学, 海洋学部, 教授 ; WASHIYAMA HIROFUMI 静岡県水産技術研究所, 上席研究員 ; FUKUI ATSUSHI 東海大学, 海洋学部, 教授
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: サクラエビ / 産卵頻度 / 成熟サイズ / 甲殻類 / 根鰓亜目 / 駿河湾 / 卵巣

Outline of Final Research Achievements

To assess stocks of sergestid shrimp Lucensosergia lucens based on the egg production method, fisheries must estimate the spawning fraction, or number of females spawning per day, and batch fecundity. Therefore, we developed a method based on the ovarian color pattern to classify matured females prior to spawning. We subsequently studied the spawning rate and the number of eggs released by mature females using shipboard spawning experiments, and characterized ovarian histology before and after spawning. The daily proportions of spawning females before and after spawning varied from 2.4 to 26.5% in 2013, and from 6.0 to 22.2% in 2014. The spawning fractions were 0.214-0.347, and the ranges were smaller than that of the proportion of females both before and after spawning. The sizes at maturity of the 2013 and 2014 cohorts were smaller than those of the 1960-1990 cohorts. Batch fecundity will be reported after further experiments.

Free Research Field

水産資源生物学