Title Length- and age-at-spawning of Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea
Author Parker, S.J.; Grimes, P.J.
Author Affil Parker, S.J., National Institute of Water and Atmospheric Research (NIWA), Nelson, New Zealand
Source CCAMLR Science, Vol.17, p.52-73. Publisher: Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), International. ISSN: 1023- 4063
Publication Date 2010
Notes In English GeoRef Acc. No: 309665
Index Terms Antarctica--Ross Dependency; Southern Ocean--Ross Sea; Antarctica; Chordata; Dissostichus mawsoni; fisheries research; histology; juvenile taxa; models; Nototheniidae; physiology; Pisces; reproduction; Ross Dependency; Ross Sea; seasonal variations; Southern Ocean; Vertebrata
Abstract Characterization of oocyte developmental cycle of Dissostichus mawsoni from fish sampled in Ross Sea during 2000- 2009 fishing seasons shows that once development begins, oocytes grow and accumulate at cortical alveoli stage for at least one year. Individual oocytes are then recruited into vitellogenic phase over at least 6-12 month period, resulting in developed group of oocytes accumulating at final maturation stage by approximately May each year. Age at 50% spawning for females on Ross Sea slope region is 16.6 years, and for males 12.8 years. Evidence of skip-spawning was observed for females only and results in flatter, right-shifted ogive, increasing functional differences between male and female ogives. Degree to which overall population ogive is biased right (older) by applying slope-derived ogive to northern Ross Sea region depends on proportion of total population occurring in northern Ross Sea, which is currently unknown.
Publication Type journal article
Record ID 91391