New Jersey Scuba Diving

Marine Invertebrates

Might as well call this the squishy section of the website. These organisms ( they aren't even all animals ) are lumped together here for their rather unappealing consistency. Disney will never make an animated adventure about any of them. That's not a scientific way to classify things, but it works pretty well for the layman.

Jellyfishes

Moon Jelly
Moon Jelly - Aurelia aurita

The many creatures on this page are lumped together for the one trait they all have in common - they are all "jelly-like" - soft, gelatinous, and more-or-less transparent. Other than that, they are for the most part completely unrelated. True Jellyfishes, Hydromedusae, and Siphonophores are in the phylum Cnidaria, related to bottom-dwelling Hydroids, Sea Anemones, and corals. Comb Jellies are in the phylum Ctenophora, and are completely unrelated to jellyfishes, as are Sea Butterflies and Corollas, which are mollusks. Salps are free-swimming tunicates, more closely related to us than to any of these other creatures.

More: Jellyfishes ...

Echinoderms

Starfish

Echinoderms ( literally "spiny skins" ) are among the strangest animals on the planet. They start out as bilaterally symmetric larvae but grow into a 5-way body symmetry as adults. Some species show six, seven, or even higher levels of symmetry. Worm-like Sea Cucumbers have re-evolved a bilateral body plan over the underlying 5-way plan. Because of certain developmental traits, it is felt that despite their strangeness, echinoderms are actually more closely related to chordates than any other group.

More: Echinoderms ...

Worms

There are many types of worms, but most species are either too small or too secretive to be found by casual scuba divers. Nudibranchs are shell-less snails that resemble worms, while Teredos are nearly shell-less bivalves that also resemble worms.

More: Worms ...

Squids & Octopus

Squids and octopuses are cephalopods ( Latin: "head-foots". ) They are extremely evolved mollusks. The shell is internalized as a support structure in squids, or completely absent, as in octopi. There are probably more squids than fish in the sea, both by numbers and by mass.

More: Squids & Octopus ...

Algae & Seaweeds

algae
A garden of green and brown algae grows on a shallow rock. Enteromorpha (Hollow Green Weed) and Fucus (Rockweed)

In our waters, plants and algae are found only in shallow water where sufficient light can penetrate for photosynthesis. It would be unusual to find algae below 10-20 ft, so our wrecks and reefs, despite the profusion of attached organisms, are actually devoid of plant life! Of course, that is completely neglecting the microscopic algal plankton that is so profuse in our waters and so lacking in the clear water of the tropics.

More: Algae & Seaweeds ...

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.

More: Air Fills ...

Disclaimer:

I make no claim as to the accuracy, validity, or appropriateness of any information found in this website. I will not be responsible for the consequences of any action that is based upon information found here. Scuba diving is an adventure sport, and as always, you alone are responsible for your own safety and well being.

Copyright © 1996-2025 Rich Galiano
unless otherwise noted

Powered by WordPress. No, really.
Cookies blah blah whatever

This website is 100% AI-free

6043 // 1432036 // 184

Printed from njscuba.net