Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge

Jun Aoyama, Shun Watanabe, Michael J. Miller, Noritaka Mochioka, Tsuguo Otake, Tatsuki Yoshinaga, Katsumi Tsukamoto

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

The Japanese eel, Anguilla japonica, spawns within the North Equatorial Current that bifurcates into both northward and southward flows in its westward region, so its spawning location and larval transport dynamics seem important for understanding fluctuations in its recruitment to East Asia. Intensive research efforts determined that Japanese eels spawn along the western side of the West Mariana Ridge during new moon periods, where all oceanic life history stages have been collected, including eggs and spawning adults. However, how the eels decide where to form spawning aggregations is unknown because spawning appears to have occurred at various latitudes. A salinity front formed from tropical rainfall was hypothesized to determine the latitude of its spawning locations, but an exact spawning site was only found once by collecting eggs in May 2009. This study reports on the collections of Japanese eel eggs and preleptocephali during three new moon periods in June 2011 and May and June 2012 at locations indicating that the distribution of lower salinity surface water or salinity fronts influence the latitude of spawning sites along the ridge. A distinct salinity front may concentrate spawning south of the front on the western side of the seamount ridge. It was also suggested that eels may spawn at various latitudes within low-salinity water when the salinity fronts appeared unclear. Eel eggs were distributed within the 150-180 m layer near the top of the thermocline, indicating shallow spawning depths. Using these landmarks for latitude (salinity front), longitude (seamount ridge), and depth (top of the thermocline) to guide the formation of spawning aggregations could facilitate finding mates and help synchronize their spawning.

Original languageEnglish
Article numbere88759
JournalPloS one
Volume9
Issue number2
DOIs
Publication statusPublished - Feb 13 2014

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Eels
Anguilla japonica
Salinity
spawning
Moon
Temperature distribution
Eggs
Agglomeration
salinity
Surface waters
Rain
eel
Anguilla
Water
Far East
Life Cycle Stages
longitude
water salinity
East Asia
surface water

All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Aoyama, J., Watanabe, S., Miller, M. J., Mochioka, N., Otake, T., Yoshinaga, T., & Tsukamoto, K. (2014). Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge. PloS one, 9(2), [e88759]. https://doi.org/10.1371/journal.pone.0088759

Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge. / Aoyama, Jun; Watanabe, Shun; Miller, Michael J.; Mochioka, Noritaka; Otake, Tsuguo; Yoshinaga, Tatsuki; Tsukamoto, Katsumi.

In: PloS one, Vol. 9, No. 2, e88759, 13.02.2014.

Research output: Contribution to journalArticle

Aoyama, Jun ; Watanabe, Shun ; Miller, Michael J. ; Mochioka, Noritaka ; Otake, Tsuguo ; Yoshinaga, Tatsuki ; Tsukamoto, Katsumi. / Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge. In: PloS one. 2014 ; Vol. 9, No. 2.
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