
TY  - JOUR
A1  - Shiao, Jen-Chieh 
A1  - Tzeng, Wann-Nian 
A1  - Collins, Adrian 
A1  - Iizuka, Yoshiyuki 
T1  - Role of marine larval duration and growth rate of glass eels in determining the distribution of <emph type="2">Anguilla reinhardtii</emph> and <emph type="2">A. australis</emph> on Australian eastern coasts
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 2002
VL  - 53
IS  - 3
SP  - 687
EP  - 695
KW  - otolith, early life history.
UR  - https://doi.org/10.1071/MF01037 
N2  - The differences in geographical distribution between Anguilla reinhardtii and A. australis on the eastern coast of Australia can be understood by comparing otolith growth increments and microchemistry, the ages between species of the eels at metamorphosis from leptocephalus to glass eels and the ages of glass eels at estuarine arrival. The ages at metamorphosis were determined from where the increment width dramatically increased and the Sr/Ca ratio dropped. The mean age (&#177; s.d.) of A. reinhardtii (n = 176) at metamorphosis was 144.5 estuarine arrival was182.7 &#177; 16.3 days. For A. australis (n = 150) it was 173.7 &#177; 20.5 days and 229.2 &#177; 29.4 days, respectively. The differences in age between species were significantly larger than the annual and seasonal variations within species. Australian eels are believed to spawn in the tropical oceans and larval eels drift in the South Equatorial Current to eastern Australia. The younger ages at estuarine arrival of A. reinhardtii suggest that the spawning grounds of this species lie closer to Australia than those of A. australis. In addition, the mean total length at recruitment of A. reinhardtii (49.9 &#177; 2.0 mm) was significantly smaller than for A. australis (54.6 &#177; 5.4 mm) (t = 3.8, P &#60; 0.01). However, the growth rates of A. reinhardtii (0.25 than for A. australis (0.23 &#177; 0.022 mm/d) (t = 7.6, P &#60; 0.01). The smaller sizes of A. reinhardtii at recruitment were likely due to the shorter marine larval period and faster growth rate compared with A. australis. The duration of the marine larval period and growth rate may be the principal factors in determining the geographical distribution of both A. reinhardtii, which tend to occur in tropical-subtropical waters, and A. australis, which predominate in more temperate waters. 
ER  -

