AUTHOR=Wang Lin , Wang Shuhong , Zeng Chaoshu , Wang Yuyue , Zeng Chunxiao 

TITLE=Effects of Food Concentration and Photoperiod on Egg Production, Female Life Expectancy and Population Dynamics of the Paracalanid Copepod, Bestiolina amoyensis

JOURNAL=Frontiers in Marine Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2021.788744

DOI=10.3389/fmars.2021.788744

ISSN=2296-7745

ABSTRACT=<p>The paracalanid copepod, <italic>Bestiolina amoyensis</italic>, is a widely distributed species occurring in subtropical inshore waters across the Pacific Ocean. Its small size, herbivorous feeding habit, and high adaptability make the species one of the most promising candidates as potential live feed for hatchery larval rearing. This study investigated effects of different feeding density of microalgae <italic>Isochrysis</italic> spp. (1 × 10<sup>5</sup>, 2 × 10<sup>5</sup>, 3 × 10<sup>5</sup>, 4 × 10<sup>5</sup>, and 5 × 10<sup>5</sup> cells ml<sup>–1</sup>) and photoperiod (8L:16D, 12L:12D, and 16L:8D) on productivity-related parameters, including egg production, female life expectancy and population dynamics of <italic>B. amoyensis</italic>. Results showed that total egg output over female lifespan, final population size and intrinsic rate of population of 12L:12D photoperiod treatments were always the highest among three photoperiod conditions, especially at the food concentration of 4 × 10<sup>5</sup> cells ml<sup>–1</sup>, indicating <italic>B. amoyensis</italic> had high reproductive performance and the population was in a more stable status. The number of nauplii from 4 × 10<sup>5</sup> cells ml<sup>–1</sup> algal concentration treatment accounted for 75% of the population, and the ratio of females to males approaching 1:1 when photoperiod was 12L:12D; female life expectancy was 10.5 ± 0.6 days. In conclusion, our results showed that <italic>Isochrysis</italic> spp. is a suitable feed for <italic>B. amoyensis</italic> with an optimal concentration at 4 × 10<sup>5</sup> cells mL<sup>–1</sup>; the optimal photoperiod for <italic>B. amoyensis</italic> rearing is 12L:12D. The relatively long reproductive lifespan and high intrinsic population increase rate make <italic>B. amoyensis</italic> a good candidate to develop culture techniques for hatchery larval rearing.</p>