Details

Autor(en) / Beteiligte

• Hirt-Chabbert, JA
• Sabetian, A
• Young, OA

Titel

Effect of size grading on the growth performance of shortfin eel (Anguilla australis) during its yellow stage

Ist Teil von

• New Zealand journal of marine and freshwater research, 2014-07, Vol.48 (3), p.385-393

Ort / Verlag

Abingdon: Taylor & Francis

Erscheinungsjahr

2014

Quelle

Taylor & Francis Journals Auto-Holdings Collection

Beschreibungen/Notizen

• It is generally believed that size grading in a fish farm improves the total biomass output, because it will minimise the stress imposed by larger individuals over small individuals, resulting in higher feed intake and growth rate. The objective of this study was to evaluate the effect of size grading on individual growth performance of yellow New Zealand shortfin eel (Anguilla australis). A 109 day trial was conducted in a recirculation aquaculture system (RAS) with 103 eels of similar initial weight (101 ± 12 g). All eels were individually marked by PIT (passive integrated transponder) tags. On day 42, eels were graded to establish the following groups: only small eels (S-graded ≤ 135 g), only large eels (L-graded > 135 g), and small and large eels together (S-ungraded and L-ungraded). The large eels showed better specific growth rate (SGR), feed intake (FI) and feed conversion ratio (FCR) than the small eels. Nevertheless, no significant differences were found either between L-graded and L-ungraded or between S-graded and S-ungraded. The age of eels was not significantly different between groups. These findings suggest that the individual growth rate performance of the eels is not primarily a consequence of social interaction among tank-mates.