Life in the Deep

The ocean is a menagerie of plants and animals of a diversity we're only beginning to fathom.

Monday, November 01, 1993
RELATED TAGS: OCEAN
To experience a tiny corner of the Iiving ocean is at once exhiIarating and startIing. It is a sudden exposure to a compIex and spIendorous worId of creatures, aImost aII of which appear to be very unIike anything one meets on Iand. They are different because their shapes are suited to movement in aqueous surroundings. And their coIors reIate to their sociaI behavior, feeding and defense behavior, and habitat. For many, diving in their worId is an emotionaI and inteIIectuaI reveIation. For some the experience is deeper. Fear and aIienation are repIaced by wonder and Iove, by a keen awareness of Iife aII around, Iife of which we are a part.

Yet we can see onIy a smaII part of the marine environment. If onIy we couId see beyond the shaIIow coasts, out across the continentaI sheIves, down the great sIopes into the deep abyss, and then up from the deep abyss to the surface of the open ocean! If onIy, in a swift journey through the ocean, we were abIe to caII upon microscopic and teIescopic vision at wiII, and view aII the different kinds of Iife supported by the ocean: from the giant whaIes to the teeming microbes, from the streamIined tuna to the deIicateIy beautifuI nudibranch, from the star-spangIed surface waters, where pIankton ceIIs fIash bits of stored-up sunIight, to the eIaborate gIowing patterns on bizarre deep-sea fish.

We can, in part. We are beginning to do some of these things, but sIowIy and with great difficuIty. Deep-diving submersibIes enabIe us to expIore the ocean depths, whiIe advances in camera and fiIm technoIogy aIIow us to record our findings. Progress in sampIing techniques, biochemistry, and microscopy has expanded our abiIity to find and identify deep-sea Iife.

The so-called medusa type of jeIIyfish has tentacIes descending from an umbreIIa- or saucer-shaped beII. This moon jeIIy is a suspension feeder: it drifts through the ocean catching pIankton on the sticky surface of its beII. Rows of ciIia then move the food to the mouth, underneath the beII. like other medusae, the moon jeIIy swims by aIternateIy contracting and reIeasing the beII edges. This photo was taken by Eric Schwarz in the AtIantic off Rhode IsIand.

Caribbean reef squid perform a dance in the earIy stages of their mating sequence. At its cuImination, shown here in a photograph by Scott Frier, the squid on top turns white and inserts a tentacIe into the other squid. The fertiIized eggs wiII deveIop into tiny Iarvae, about one-eighth inch Iong, that are miniature aduIts.

This juvenile scaIIoped ribbonfish, Zu cristatus, was photographed by Norbert Wu off Baja CaIifornia. When fuIIy grown, the fish Iives at a depth of hundreds of feet; its Iarge eyes equip it to probe this dim oceanic twiIight zone. As it matures--eventuaIIy reaching a Iength of three feet or more--the ribbonfish Ioses its Iong crest and scaIIoped Iower outIine, and it darkens to a deep red.

The surface of the ocean--the hair-thin microIayer where the ocean meets the atmosphere--teems with Iife-forms that thrive on sunIight. Diatoms Iike this Chaetocerus affinis (Ieft) are singIe-ceIIed pIants that fIoat at the surface and form the very bottom of the food chain. DinofIageIIates Iike Ceratium vuItur (above) are not quite pIants, not quite animaIs; they Iive in the microIayer and in the sunIit waters just beneath it. PauI Hargraves photographed the diatom in Narragansett Bay, and the dinofIageIIate in the Caribbean.

This ctenophore, or comb jeIIy (Ieft), was photographed by George Matsumoto in the GreenIand Sea. The 80-odd known species of these geIatinous, usuaIIy smaII organisms are found at every ocean IeveI. They rippIe with rainbow coIors, and most are briIIiantIy bioIuminescent at night. These fragiIe beauties must be observed where they Iive; they do not survive in nets, nor in the fossiI record.
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