Sunfish: what do we know?

Sunfish: what do we know?

What have we learnt from our day of sunfish science?

Te Papa and Auckland Museum scientists discuss how to proceed with the sunfish dissection. Photographer: Ruth Hendry © Te Papa
Te Papa and Auckland Museum scientists discuss how to proceed with the sunfish dissection. Photographer: Ruth Hendry © Te Papa

Sunfish are very hard to sex!

The best we can say is that it’s a boy. We think. We’ll have to wait for the test results to determine conclusively whether it’s male or female.

Jellyfish are delicious

Although we can’t quiz a sunfish on their taste for jelly, we can draw some conclusions. The specimen’s stomach was filled with long jellyfish tentacles, suggesting that it had eaten jellyfish shortly before it’s death. There were even some jellyfish tentacles still in its mouth!

Scientists have taken samples of the tentacles to see what species of jellyfish the sunfish has been feeding on. This will also help us to determine what depth the sunfish feeds at, as different species of jellyfish feed at different depths.

A surprising opening

A surprising finding for the scientists is that the sharp-tail sunfish has two openings: a urogenital and an anal opening. Prior to this research, sunfish had been thought to have only an anal opening. Although it may seem trivial, this finding will help scientists to find out more about how sunfish  breed and live.

Sunfish have a thick layer of fat. Photographer: Ruth Hendry © Te Papa
Sunfish have a thick layer of fat. Photographer: Ruth Hendry © Te Papa

Parasite city

Our sharp-tail sunfish was home to lots and lots of parasites, both internal and external.

It’s liver was infested with worms and was found to be diseased, a possible cause of death.

Window into a sunfish. Photographer: Ruth Hendry © Te Papa
Window into a sunfish. Photographer: Ruth Hendry © Te Papa

What next?

The sunfish has been put in what looks like a jacuzzi, but is actually a custom-built tank filled with formalin. This helps to kill bacteria and fungi. After three months, the specimen will be transferred to a 1600-litre tank, ready to reveal further secrets to our scientists.

It’s probably the biggest (wet) sunfish specimen in the world and we were very lucky to watch as the scientists carried out their initial research.

Thanks for joining in with our live sunfish science! If you have any questions, contact us on the blog or tweet us @Te_Papa using the hashtag #sunfishtepapa.

2 Comments

  1. Saw lots of these in northern B.C this summer while recreational fishing. Lots of jelly fish for them to eat.

  2. Saw lots of these in north B.C while recreational fishing this year. Lots of jelly fish for them to eat.

Leave a Reply

Your email address will not be published. Required fields are marked *