Skip to main content

Story: Freshwater fish

Black flounder

Black flounder

The black flounder (Rhombosolea retiaria) is one of two species of freshwater fish that are derived directly from marine species. The other is the torrentfish (Cheimarrichthys fosteri). The black flounder is most common in the sea, in estuaries, harbours and lower levels of rivers, but it has been seen 250 kilometres up the Whanganui River, and 100 kilometres up the Manawatū River.

Using this item

Department of Conservation

Reference: 10048525

by W. Farelly

This item has been provided for private study purposes (such as school projects, family and local history research) and any published reproduction (print or electronic) may infringe copyright law. It is the responsibility of the user of any material to obtain clearance from the copyright holder.

All images & media in this story

How to cite this page

Bob McDowall, Freshwater fish – Evolution and characteristics, Te Ara – the Encyclopedia of New Zealand, https://teara.govt.nz/en/photograph/11108/black-flounder (accessed 4 June 2026).

Story by Bob McDowall, published 1 March 2009.

Comments

Dave
07 May 2016
I spotted a black flounder in the Hutt River this morning. It would have been about 250-300mm long. It was in some quite fast flowing water. It about the 3rd time I have seen them there although not as big.
Rob French
21 February 2011
I was fishing on the Mangatutu Stream in Hawkes bay which slpits off the Tutaekari and saw a flounder up there. I was astounded as i did not relaise we had freshwater flounder in our rivers. It was very yellow with pronounced spots on it's back so i presume a Black Flonder. It was about 200-250mm long.
Gavin Boyd
09 February 2011
I saw one today about the same size as Fiona McNeil above just a bit further up stream while playing around in the water with my 6 year old. Before today I did not know we had them so far upstream.
Fiona McNeil
02 January 2011
We can report that we sighted a black flounder in the river at the Waipukurau railway bridge while fishing this week - it was at least 150mm wide and approximately 220mm long .