Oceanic Pufferfish

I was recently contacted by someone who had found a pufferfish washed up on Eastern Green beach at Penzance. It was taken to a local tackle shop, Newtown Angling, and frozen until i could collect it and take it to the Marine Biological Association for identification.....

The pufferfish was washed up in a very good condition which would suggest it had died and been washed up very recently, likely within the last day. The gills were red with oxygenated blood and scavengers had not attempted to eat it.

I had identified another pufferfish earlier in the year that had washed up on Hayle beach and this one looked to be the same species - an Oceanic Pufferfish, Lagocephalus lagocephalus. I took the puffer along to the MBA for formal identification and it was verified as L. lagocephalus. 

The oceanic pufferfish is a very rare visitor to UK waters, preferring warmer waters, with only a small number having ever been recorded before. It appears that the warmer summer and subsequent higher water temperatures has brought them into UK waters. What makes this particular specimen interesting is that it is longer and heavier than the current maximum reported for the species. Current literature states the maximum total length to be 61.0cm and maximum weight to be 3.2kg. The specimen washed up in Penzance had a total length of 66.1cm and a weight of 3.295kg. 

This species of pufferfish is incredibly toxic as it produces the potent neurotoxin Tetrodotoxin. This is the same toxin that makes the 'Fugu' pufferfish such a notorious fish in Japanese cuisine, requiring licensed chefs, who have taken years of training, to prepare and cook the potentially deadly meal. 

The Oceanic pufferfish mainly eats crustaceans and squid, and has an impressive set of 4 teeth to deal with them. Looking closely around its mouth its possible to see scarring and sucker marks from battles with squid!

The scientists at the MBA decided it would be interesting to dissect the puffer to see if we could find a cause of death, have a look at its stomach contents and to have a look at the structure of its expanding pouch.

The pouch is located on the belly of the fish, highly folded and elastic and houses small bony spines which protrude when the pufferfish puffs up.

Within the belly pouch there was what appeared to be a modified stomach with highly elastic walls which would fill with water and cause the pufferfish to expand when threatened. 

The pufferfish had 2 large ovaries, therefore is a female. Upon dissecting one of the ovaries a parasite was found and had caused the area around it to become black and degraded. It is possible that this parasite led to an infection that caused the death of the pufferfish. If this ovarian parasite is species-specific to Lagocephalus lagocephalus it is possible that this a species new to science. It was fixed in formalin for further identification at a later date. 

Several crab carapace parts, legs and claws where found in the pufferfish intestine so it would appear that it had feasted upon a few crabs as its last meal. There were no signs of squid beaks which is unusual as there are many squid currently inshore in the Penzance area where this puffer would have been prior to death and being washed up. If in ill health, it is possible that the puffer had not been feeding well. 

As a memento of the impressive pufferfish i decided to extract and keep it teeth!

If anyone would like more information on this pufferfish or to use any of the images feel free to contact me. Likewise if anybody finds a pufferfish washed up, or catches one alive, take plenty of photos of it and, if already dead and if possible, freeze it and i can arrange for a formal identification of these unusual and interesting fish.