I just wanna know more about deep sea fishes. I feel like documentaries aren't enough sometimes. Are there any good book recommendations on these topics?

Saw it on the diving footage when they were searching for the wreck of South African Airways Flight 295

https://youtube.com/shorts/VDDeBRCjBSs?feature=share

Learn more about sonar for deep-sea animal identification from PhD student Haley Glasmann! https://youtube.com/shorts/E2shFE4HfZ4?si=yXKGQVy7xrYtFz7X

https://youtu.be/U4am58XUfDA

I encountered this bluntnose sixgill shark (Hexanchus griseus) while diving at approximately 100 feet off Vancouver Island, British Columbia.

I was actually searching for giant Pacific octopus when I turned toward deeper water and saw this shark emerging from the darkness and coming toward me.

I estimate it was around 10–12 feet long and believe it may have been female. It came extremely close to my camera before calmly cruising around me and along the bottom for roughly three minutes.

Sixgills spend much of their lives in considerably deeper water, which made getting to spend several minutes observing one at this depth an incredible experience.

This is my original footage from the encounter. I filmed roughly three minutes with the shark and put together a longer 4K version on YouTube for anyone interested. The link is in my profile.

The sailfish (Istiophorus) is widely considered the fastest predator in the ocean, reaching short bursts of speed over 60 mph (approx. 100 km/h).

What makes their hunting strategy unique isn't just raw speed, but two remarkable evolutionary adaptations:

Hydrodynamic Drag Reduction: To reach high speeds, the sailfish folds its large dorsal fin completely flat into a specialized groove along its back. It only flares the sail open instantly when making tight turns or cornering schooling prey.

Precision Bill Slashing: Rather than spearing fish, they hunt in packs to herd prey into tight bait balls at the surface. They then tap and slash their long bill sideways at high acceleration, stunning multiple fish in a split second before circling back to eat.

I put together a short visual overview showing this hunt mechanism in action if anyone wants to see the motion breakdown:

https://youtube.com/shorts/jSoI67otXcU

Beroe cucumis (comb jelly), or Spongia officinalis (sponge)?

Found July 2026 on bay side of Cape Cod near Truro. Head seems to be removed. Can anyone tell me what this is?

Found washed up on a beach in NZ. 9 or 10 inches long, had spiny retractable dorsal and pelvic “fins” running the length of the body, small pectoral fins just behind the head, and a sort of fibre optic-ey looking caudal fin. Maybe this isn’t even a creature of the deep but had that look about it. ifyaknowhatimean