Betta Fish: is Chips depressed?

overview:

hi all! i purchased and added Chips to my cycled 25l tank on Wednesday, but he’s been lethargic and refusing to eat and i worry that he might be depressed and not settling in well.

he spends most of his time at the surface of the water in the back corner of the tank (although occasionally deigns to swim around so i can get a good look at his gorgeous fins). this morning i woke up to him in a near identical position to where id last seen him yesterday evening. i don’t know if he simply didn’t move all night or if this is just his favourite spot.

he wouldn’t eat the betta flakes i’d bought for him, so i contacted the LFS from which i’d bought him to see what they feed their bettas. i’ve bought the pellets he’s used to, but he won’t eat those either. there’s a chance he’s nibbling on my sizeable daphnia population, but he has early stage diamond eye so i doubt he’s able to catch them frequently. he occasionally nips at snails and appears to enjoy knocking them off floaters/glass/plants, but doesn’t seem to eat them.

he hasn’t bothered my cherry shrimp at all, and they don’t seem scared of him, which is nice.

his swimming pattern appears to be fairly jerky. unsure if this is just how longfin bettas swim or if this is something i ought to be concerned about.

he blows bubbles but has not made anything resembling a bubble nest.

he has no response to my finger being gently placed in his vicinity (not touching him, obviously!).

summary of concerns and tank parameters:

tank is heavily planted with plenty of tannin-releasing botanicals. heater set to 27°C. upon his arrival, i dissolved and added approx 5g of aquarium salt to the tank (none since). 10-15% water change performed every four or five days. ammonia and nitrites reading at 0, nitrates less than or equal to 10ppm. pH around 7.2-7.5. tank is cycled. 25l.

physical concerns: jerky movement, dorsal fin appears clamped, lethargy, refusal to eat. lack of flaring when offered mirror.

images of Chips and tank: