Journal Article Growth of an Inshore Antarctic fish, Trematomus newnesi (Nototheniidae), off Adelie Land

10 ( 2 )  , pp.167 - 172 , 2016-06
ISSN:18739652
Description
Dusky rockcod, Trematomus newnesi, is a widely distributed neritic circumpolar Antarctic fish species. We conducted a study on age and growth of T. newnesi in coastal waters of Adélie Land in East Antarctica. A total of 289 specimens were collected in 2003, 2005, 2006 and 2009. They consisted of 122 females, 132 males and 35 immature specimens. Total length (TL) and total weight (W) of these fish ranged from 13.5 to 25 cm and 19.7–174 g respectively for females and from 12 to 20.9 cm and from 24.1 to 144.1 g for males. The TL/W relationship was described by the following parameters: a = 7.2.10−3 and b = 3.127, showing no significant difference between sex (ANCOVA, P < 0.05). Fish age was estimated by counting annual growth increments on polished transverse sections of sagittal otoliths. Age estimates varied from 3 to 14 years. There was a significant relationship between otolith morphological features (weight and radius) and age with no difference between males and females (p > 0.05). The estimated values of Von Bertalanffy growth curve L∞ (cm), W∞ (g) and k were 26.6, 200.6 and 0.13 for females and 24.5, 147.0 and 0.15 for males respectively. The indices of growth performance between sexes were not significant. However, potential difference in growth rate between the morphs cannot be neglected.
2003から2009年にかけてアデリーランド沿岸で採集したハゲギス289個体(雌122個体・雄132個体・未成熟35個体)の年齢・成長を解析した。雌は全長13.5~25cm・体重19.7~174g,雄は全長12~20.9cm・体重24.1~144.1gで,全長と体重の関係には,有意な雌雄差は認められなかった。耳石の解析より,年齢は3~14歳と推定された。ベルタランフィ成長式より極限体長と極限体重は,それぞれメスでは26.6 cmと200.6 g,オスでは24.5 cmと147.0 gであった。成長に関する指数に有意な雌雄差がなかったが,本種で知られている異型間での差異については否定できない。

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