New Jersey Scuba Diving

Nudibranchs

Nudibranchs

Idulia spp, Coryphella spp, others

Size: 1/2 " to 4"

Nudibranchs or Sea Slugs are not worms but shell-less gastropod mollusks, related to garden slugs. Their closest relatives here are planktonic Sea Butterflies. Some types of nudibranchs, including those shown here, assimilate the functioning stinging cells of their food, and should not be handled for this reason.

Nudibranchs

Red-Gilled nudibranchs feeding on hydroids, with which they are often found. They grow to 2 inches.

Nudibranchs — Maned Nudibranch - Aeolidia papillosa

Maned Nudibranch

The Maned Nudibranch feeds chiefly on sea anemones, with a preference for the Frilled Anemone. The animal tends to take on the color of the anemones on which it preys. The Maned Nudibranch is 4" long, 1-1/2" wide, thick, and stubby. Its coloration is whitish, gray, or tawny-brown, with pale speckles. The nudibranch's back is covered with hundreds of slender, finger-like projections with a bare area down the midline. It has 2 pairs of antennae on a squarish head and its rear end is tapered to a blunt point.

Maned Nudibranch

Air Fills

The proper way to fill a scuba cylinder is very slowly so that the heat generated by the filling process can be bled away as it happens, and the tank does not become overheated. That's a great theory, but in real life, nobody does it that way. Most tanks are "hot-filled", that is to say, that they are filled too fast to prevent them from heating up during the process. If they are filled directly off a compressor, then they will receive a very hot fill. You would be surprised how warm the surface of a tank can get. This is not much of a safety issue, though, as it is well within the thermal limits of the material, either aluminum or steel.

The real issue here is that eventually ( after a few hours ) the tank will cool down, and as it does, the air inside will contract, and the pressure will drop. This typically results in about a 10% loss of pressure. At this point, you could top it off to the rated pressure again and have a truly full tank. Most of the time that's not an option. Therefore, if the shop hot-fills your tank to 3000, you will end up with 2700. To get 3000, you need to fill the tank to about 3300. While this is verboten, it is well within the 5/3 overpressure of the hydro test, and realistically there is no danger. The slight overpressure may wear out your o-rings a little faster, but o-rings are cheap - get a dozen of them at the hardware store for a buck.

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