Preliminary age-based life history characteristics of the dogtooth tuna,Gymnosarda unicolor(Ruppell,1838),in the southwest Pacific Ocean  

作　　者：David J.Welch Adam K.Smith Kyne Krusic-Golub Sandra Erdmann Stephen J.Newman 

机构地区：[1]C_(2)O Fisheries,PO Box 3041,Cairns,Queensland,4870,Australia [2]Centre for Sustainable Tropical Fisheries and Aquaculture,College of Science and Engineering,James Cook University,Townsville,4811,Australia [3]Reef Ecologic,Townsville,Queensland,4811,Australia [4]Fish Ageing Services Pty.Ltd.,Queenscliff,Victoria,3225,Australia [5]Western Australian Fisheries and Marine Research Laboratories,Department of Primary Industries and Regional Development,Government of Western Australia,North Beach,Western Australia,6020,Australia

出　　处：《Aquaculture and Fisheries》2023年第3期323-331,共9页渔业学报（英文）

摘　　要：Dogtooth tuna,Gymnosarda unicolor were sampled off the east coast of Australia(southwest Pacific Ocean)from 2007 to 2012.Ages were determined by examining thin transverse sections of their sagittal otoliths and were based on counts of alternating opaque and translucent zones(annual growth increments).Growth was rapid during the first year of life,after which growth in length was much reduced.Parameters of the constrained von Bertalanffy growth function(fork length-at-age)were L∞=1164.77(mm,FL)and K=0.44 year^(-1).Preliminary estimates of longevity indicate a maximum observed age of at least 20 years.There was a high degree of variation in the observed length and age of sexual maturity for G.unicolor.Despite this variation,the size at 50%maturity for female G.unicolor estimated in this study was 713 mm FL(<2 years of age).The diet of G.unicolor is very broad and covers a range of fish species.The life history characteristics of G.unicolor overall,indicate that this species may be somewhat resilient to fishing.However,reports of localised depletions,in association with heavy targeting by sports fishers,low effective population sizes and patchy recruitment indicate that this species is particularly vulnerable to overfishing.

关 键 词：Otoliths Age Life history Pacific ocean DIET Fisheries management 

分 类 号：S931.1[农业科学—渔业资源]