This did not feel like a Thursday puzzle to me, and I find myself on an 11-day streak. This seemed like a frustratingly hard Tuesday rather than a Thursday, but this has been me kinda rediscovering the crossword.

I pulled out 13A Twine material: SISAL because I am unfamiliar with that. And while looking it up, I came across an interesting question! “Sisal vs. Jute: What’s the difference?”
If you’d asked me at any point before 7:45pm on Wednesday (when I’m writing this) if I knew the differences, I’d say that they’re the same because they’re both words that aren’t real.
But I’d be wrong on both counts.
They’re not the same, and they’re both real things.
According to SisalRugs.com, sisal comes from agave, and jute comes from jute plants of India and Bangladesh.
So they’re two plants that look the same, right?
Wrong! So, so wrong!

This looks nothing like agave!

The theme of this puzzle was a boatload of fun.
4D Xbox or PlayStation: GAMECON(S)(O)+(L)+(E).
Sole!

Sole are born with eyes on either side, but one eye migrates, and they swim parallel to the ocean floor. Halibut do the same!
8D Finishing touch on the first transcontinental railroad: GOLDENS(P)(I)+(K)+(E).
Pike!

37D Drink that might be served with a metal cup: MILKS(H)(A)+(K)+(E).
Hake!

38D Vedic religious text: UPANI(S)(H)+(A)+(D).
Shad!

1D With 11-Down, what each of this puzzle’s groups of circles represents: FISH.
11D See 1-Down: HOOK.
It makes a fish hook! And fish are on the hook!
Finished this one in 16:41. I’d thought it might be a record for me, but my best Thursday was 13:09 back in October of 2018.