Reproductive life history of sablefish (Anoplopoma fimbria) from the U.S. Washington coast

PLoS One. 2017 Sep 8;12(9):e0184413. doi: 10.1371/journal.pone.0184413. eCollection 2017.

Abstract

Sablefish (Anoplopoma fimbria) is a marine groundfish that supports valuable fisheries in the North Pacific Ocean and holds promise for marine aquaculture. Limited information is available, however, about its reproductive biology. This study aimed to characterize the complete reproductive cycle, including seasonal changes in gonadal development (macroscopic and histological), plasma sex steroid levels (17β-estradiol -E2-, and 11-ketotestosterone -11KT-), gonadosomatic and hepatosomatic indices (GSI, and HSI), and condition factor (K) of female and male sablefish captured off the Washington coast. Adult fish (209 females, 159 males) were caught by longline monthly from August 2012 to August 2013. Early signs of recruitment of ovarian follicles into secondary growth, indicated by oocytes containing small yolk granules and cortical alveoli, were first observed in March. Oogenesis progressed during spring and summer, and fully vitellogenic follicles were first observed in July. Vitellogenic growth was correlated with increases in plasma E2, GSI, HSI and K. Periovulatory females, indicated by fully-grown oocytes with migrating germinal vesicles and hydrated oocytes, were found from November to February. At this stage, plasma E2 and GSI reached maximal levels. In males, proliferating cysts containing spermatocytes were first observed in April. Testicular development proceeded during spring and summer, a period during which all types of male germ cells were found. The first clusters of spermatozoa appeared in July, concomitant with a 5.2-fold increase in GSI. Spermiating males were observed from November to April; at this time, spermatids were absent or greatly reduced, and testis lobules were filled with spermatozoa. The highest levels of plasma 11KT were found in males at this stage. Postspawning ovaries and testes, and basal steroids levels were found in fish captured from February to April. These results suggest that sablefish in coastal Washington initiate their reproductive cycle in March/April and spawn primarily in January/February.

MeSH terms

  • Animals
  • Female
  • Fishes*
  • Geography
  • Gonadal Steroid Hormones / blood
  • Gonads
  • Male
  • Ovarian Follicle
  • Ovary / cytology
  • Ovary / embryology
  • Quantitative Trait, Heritable
  • Reproduction*
  • Seasons
  • Testis / cytology
  • Testis / embryology
  • Washington

Substances

  • Gonadal Steroid Hormones

Grants and funding

This research was supported by funding from National Oceanic and Atmospheric Administration Cooperation Research Program and National Oceanic and Atmospheric Administration Office of Aquaculture to FWG and PS. JMG received a postdoctoral fellowship form The National Academy of Sciences. Ocean Associates Inc. provides professional consulting services to government organizations, UN agencies, academia, non-governmental organizations, and the private sector. In the current study NOAA contracted Ocean Associates Inc. to provide a qualified contractor to help in conducting the research project. The funder provided support in the form of salary for author CJ, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of this author are articulated in the ‘author contributions’ section.