“Or I guess I should call it a school of snakes,” said Sandra, as the cloud grew closer.
“Ribbonsnakes,” said Dan. “Like the ribbonfish on Earth... swimming in formation like a flock of geese, except they are swimming vertically instead of horizontally.”
The school of animals were indeed shaped like ribbons, very thin and very long, but wide all along their midsection. They swam through the air with a vertical waving motion. They looked like a ribbon waving in the wind, but instead of merely responding to the wind, they were the ones doing the waving, moving themselves along by pushing on the pockets of air they had crested. On each side of the “leader” ribbonfish, and one “wavelength” behind, were two other ribbonfish, riding on the “wake” the leader fish had made. The vertical “V” formation looked very much like those formed by migrating geese.
“Hey! What’s happening!” complained Dan, as the capsule suddenly spun on its axis, rotating the ribbonfish formation out of his line of view.
”They’re flying by, and aren’t going to get any closer, so I’m having Rod rotate the telescope around,” replied Sandra over the intercom link. “I want to get a close-up view of those creatures. I don’t see any eyes or mouth and they’re too thin to have a big gut.”
After the flock had flown away, Sandra and Dan had time to look closely at the enlarged images of the
Infula natrix,
or “ribbon-shaped swimming-snakes”—the name Jeeves and Sandra had given the creatures in order to avoid confusion with Earth ribbonfish.
“No sign of a mouth,” agreed Dan. “And awfully thin. The big ones are hundreds of meters long and four meters wide, but only a few centimeters thick. They certainly aren’t floaters. That’s a lousy surface-to-volume ratio for a balloon.”
“Pure swimmers,” said Sandra with certainty.
“With no mouths, they can’t be ‘hunters’ in the usual sense,” said Dan, highly puzzled.
“Maybe there
is
a mouth, but we can’t recognize it,” suggested Sandra.
“Well,
I
sure can’t,” said Dan. “And with no eyes they wouldn’t be good hunters anyway.”
“There are a number of dark spots spaced along the edges of the creatures,” said Sandra. “There seem to be more of them at the ‘head’ portion than along the sides and at the tail. Perhaps those are the eyes.”
“There could be a lot of small eyes like those on a scallop,” suggested Dan. “More for detection of shadows than for imaging.”
“Scallops have eyes?” interjected Rod, who had been listening to the two scientists while keeping the balloon headed north.
“Scallops have a couple of dozen cute little baby-blue peepers stuck up on stalks, all around the perimeter of the tasty part—the better to see you with,” said Dan. “If they spot the shadow of a predator, they snap their shells shut and the water squirting out between the two closing shells jet-propels them away from harm.”
“Scallops have
eyes!?”
exclaimed Rod again, more loudly this time. “I didn’t know they had eyes! I don’t think I’ll ever eat scallops again!”
“Then again, the ribbonsnakes may see by sonar,” said Sandra, ignoring Rod’s histrionics. “And those dots are some other organ.”
“Or maybe the spots are just pure decoration,” added Dan. “That’s the trouble with
real
alien lifeforms ... it’s hard to interpret what you observe.”
They finally gave up and stored the images away in the bottomless depths of Jeeves’s memory, remembering to send copies to their scientific colleagues back in Mission Control on Earth. The five-hour-long “day” was over, so they went back to bed for a nap, in order that they would be ready to search the skies when sunrise came again.
The next day’s search was highly successful. There were breaks in both the ammonia and water cloud layers, and yellow sunbeams would shine down to their level. In many cases the distant sunbeams would illuminate creatures floating through the air. Fortunately the telescope had motion compensation, so high magnification could be used, and they obtained brightly illuminated high-quality images of a number of different air creatures.
“This one looks familiar,” said Dan as he zoomed the telescope in on a large creature illuminated from above by a beam of sunlight. “It’s a bigger version of the
Annulus
ringswimmer that I rescued from the drop of water.”
“You’re right,” agreed Sandra as she looked at the jellyfish-like creature. There was a large toroidal balloon that provided basic flotation. Hanging down from the outer perimeter of the fat ring was a cylindrically shaped, slowly pulsating thin membrane that pushed the creature upward with each pulse. Acting in synchronism with the outer membrane was a smaller, conical membrane hanging down from the inner perimeter or “mouth” of the creature. When the outer membrane was contracting, the inner membrane collapsed, blocking the hole in the ring and forcing the thick air out the bottom to produce the jet pulse that pushed the creature upward. When the outer membrane was expanding, the inner membrane opened, drawing fresh air, laden with microscopic bits of food, inside for the next pulse. Both membranes were covered with long cilia that captured the food out of the air as it passed through the creature.
“Those pulsation cycles are taking almost a whole minute to complete,” said Dan. “That must mean that the creature is quite large. It’s hard to tell at this distance. Jeeves?” he asked, “What’s the size of that thing?”
“The outer diameter of the flotation ring is ten meters, while the total length from the top of the ring to the base of the outer membrane is about fifty meters,” replied Jeeves.
“That’s as big as the
Sexdent!”
exclaimed Dan. “It’s amazing how big the thing is, compared to the tiny specimen that we captured in the cloud net. You’d think a creature that large would spawn larger children.”
“For all its size, it is still very primitive,” replied Sandra. “There are jellyfish almost that big back in the oceans of Earth, and they too have microscopic spawn.”
“But you would think that because it depends upon a flotation ring to keep afloat, there would be a minimum size for survival. The membrane of the flotation ring can only be made so thin. The smaller the volume enclosed, the greater the proportion of the membrane mass to the total mass. There has to be a minimum size below which a ‘floater’ turns into a ‘sinker.’ “
“You’re forgetting that the ringswimmers can swim as well as float. When they’re small, they keep afloat by swimming, which is easy when you’re a tiny creature. At that size, swimming through the thick air here on Saturn is like swimming through molasses—you sort of ‘crawl’ through the air. Later, after they get bigger, and swimming is less effective, the flotation ring keeps them up between strokes.”
The short “sunlit” day was nearly over when Dan noticed a large water cloud forming in an otherwise clear patch of sky.
“Looks like a thermal column is forming over there,” he said, marking the angle to the cloud using the direction-finding. ability of the biviewer he was using.
“Where?” asked Seichi with some concern, for he was acting pilot for this shift. “I want to make sure I avoid it.” Jeeves marked it on the situation display. It was well off to the east, far from their planned track northward.
“A thermal column means hot air rising up from the lower depths,” said Sandra. “There’s bound to be some critters rising sunward along with the air. Rotate the telescope viewport around to that side, Seichi.”
“It’s a pretty big cloud,” Dan warned her. “Must be pretty dark underneath it.”
Fortunately, with the Sun setting in the west, the illumination was nearly perfect for viewing the contents of the rising column of air in the thermal.
Dan increased the zoom on the biviewer. “Specks!” he announced. “Thousands of specks!”
“Come on!” Sandra swore impatiently as she shoved the telescope drive icon to its maximum slew speed. Finally the specks showed up on the imager—greatly magnified compared to the maximum zoom available through Dan’s biviewers.
“Balloons!” she exclaimed as the slewing stopped and the images steadied on her screen. “Thousands of balloons!” Slowly she scanned the telescope up and down the rising column of iridescent spheres. “Big balloons rising fast near the top of the column until they disappear into the bottom of the cloud and smaller balloons rising more slowly down below.”
“That makes sense,” said Dan. “The bigger the balloon is, the better the lift-to-mass ratio.”
“What are you going to name them?” asked Dan.
“It’s already been named,” said Sandra. “This is one of the few saganlife species where the images returned from the Saturn penetrator probes contained enough information to allow firm classification. This species is the
Bulla volitare,
or ‘bubblefloater.’ Just to make sure, I’ll need to take a closeup. view of the underpinnings.” She zoomed the telescope in on the bottom part of one of the larger balloons rising up above them. Dan came over to look at the expanded image in the display.
“Yep,
Bulla volitare,
all right,” she murmured, pointing at the screen. “A multitude of long sticky tendrils hanging down from the perimeter to catch the food, just like on an Earth jelly-fish.”
“What is that long tubelike thing hanging down inside the fringe of tendrils?” asked Dan.
“Looks like a penis to me,” said Rod, who had come to the upper deck to take over the pilot duties from Seichi.
“It’s
not!”
said Sandra primly. “It’s a proboscis—used for sucking up the food bits that land on the sticky tentacles—at I least that’s what was deduced from a series of images we got from the last imaging probes. Let’s watch it in action and see if they got it right.”
As they watched, the proboscis made a spiraling motion around the inside of the curtain of tendrils, occasionally stopping as it coped with a particularly large “bite.”
“Look!” said Dan. “One of the smaller balloons has been captured by the tendrils of a larger balloon.” The impact of the large prey on the tendril curtain caused the proboscis to halt its spiral search pattern, and it swung across the interior of the curtain of tendrils to the other side. By the time it arrived, the balloon portion of the captured bubblefloater had deflated.
“I bet it deflated in an attempt to make itself too heavy to hold up,” said Dan. “But it doesn’t seem to have worked. Those tendrils must be really sticky.”
“Yet, the fact that the bubblefloaters have evolved an escape strategy indicates that they have at least a modest intelligence,” remarked Sandra, who was already planning her next hyperpaper. This would be a spectacular one, with all the video images she would be able to include along with the text.
“Looks like the proboscis is going to get a nice big chunk of meat to eat for a change,” said Rod, fascinated by the scene, “instead of a constant diet of little tidbits.”
“It would really be a shame if such pretty creatures as the bubblefloaters turned out to be cannibals,” said Sandra. She then felt a little ashamed at making such a judgmental statement. Certainly these creatures were so limited in intelligence that they could be forgiven for eating their own kind. Nevertheless, she was relieved when the proboscis, instead of tearing away at the captured balloon, lifted off the sticky tendrils one by one and allowed the captured balloon to drop free.
“Let’s look at some of the other bubblefloaters,” said Sandra, using the icon control to slowly slew the telescope from one target to another. There was enough light that she could split the incoming beam into two different images with different magnification, one of which showed the swirling cloud of rising balloons as small glistening dots, while the other gave the expanded image in a window superimposed on the broader view. She stopped at one pair of dots, then quickly swerved past.
“Say!” exclaimed Rod, who had been watching a copy of Sandra’s screen on his console. “Go back to that one! Are they doing what I think they’re doing?”
Sandra’s face turned beet red as she hesitated. “Very well,” she said, the scientist in her annoyed with herself for having acted so prudishly. She swerved the magnified window back until it was centered on the two dots. There were two bubble-floaters rising together, side by side, holding “hands” by their tendrils. The proboscis of each was extended over underneath the tendril curtain of the other, with the tip of each proboscis buried deep within the dense “core body” at the base of the flotation sphere.
“I told you those long things looked like a penis,” said Rod loudly.
“They
could
be feeding each other,” said Sandra, but even she didn’t believe that.
They kept the telescope on the rising coupled pair, but nothing happened.
“They really make it last a long time,” said Rod, impressed.
That remark was enough for Sandra, and she swerved the telescope off to other targets. Just before the Sun set behind an ammonia cloud, they spotted a bubblefloater with babies. Below the large spherical float of the “mother” bubblefloater were a dozen smaller balloons. Each seemed to be fixed to a number of the sticky tendrils, up near the base of the tendril where it came out of the equator of the flotation sphere. The proboscis of the mother not only brought food to the mouth of the parent, but occasionally would take a tidbit up to one of the babies, where it was eagerly grabbed by the proboscis of the little one and transferred to its tiny mouth.
“That makes evolutionary sense,” said Dan approvingly. “Pure floaters can’t start out small—the mass-to-volume penalty for small floaters makes it impossible for them to stay up. So Momma grows them up to a good size and lets them out when they are big enough to float on their own.”