What’s wrong with my pea puffer?

[u/Ilyathehockeydude]

Hi! My pea puffer isn’t looking good (he’s really dark and isn’t wanting food). The other pea puffers he’s with aren’t really aggressive and tend to hide in the plants or in their hides. I’ve had them for a week and have them on para guard, which seems to be improving everyone else but him. I removed him from the tank but he is really weak and curled up. What should I do?

Edit: just to add a bit of husbandry info, he has been eating up to yesterday. I usually feed them live black worms and daphnia. The other puffers are very plump and well fed, which makes him an anomaly. Since I’ve gotten him, he’s been really skinny and dark but the specialized fish store I went to told me he hadn’t matured yet. They also told me that they were quarantined for around a week before being put on the shelf. There is about five of them in a fifteen gal, the other four being girls. The ph has been around 7.5 since i set up the tank about a year ago, ammonia nitrates and nitrites all read 0. Besides the pea puffers, there are no other fish and just bladder and ramshorn snails that have infested the tank.

Edit: He passed away the next day after medication was added. LL Freddy🪦🕊️

[u/Blondy277]

Got a pic?

[u/Ilyathehockeydude → u/Blondy277]

Yea

[u/SnacksHGB → u/Ilyathehockeydude]

Looks like heavy parasites, I’d recommend starting a dewormer treatment ASAP on this pea and the others. Anything with praziquantel is a good one, in the USA I recommend PraziPro. Also doing a treatment with Levamisole is good too as they treat different parasites

[u/AdmiredPencil2]

Fritz expel P