Speculative Evolution -> The Tetrarch (2024)

The Tetrarch, Divine Selection

Track This Topic | Email This Topic | Print This Topic

Weirdfish

Posted: Apr 10 2019, 03:37 PM

Speculative Evolution -> The Tetrarch (2)
Squillious Squimber

Speculative Evolution -> The Tetrarch (3) Group: Members
Speculative Evolution -> The Tetrarch (4) Posts: 146
Speculative Evolution -> The Tetrarch (5) Joined: 21-August 18

'); }if("Deuterostome" != "") { document.write('Gender:

Deuterostome

'); }if("Wisconsin" != "") { document.write('Location:

Wisconsin

'); }if("Hahaha "expertise"" != "") { document.write('Field of Expertise:

Hahaha "expertise"

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: None


Speculative Evolution -> The Tetrarch (6)

Oarpedes And Other PD Ta. Trilobites

As one might expect, the five species of trilobite exploded across the early Tetrarch's mudflats, divine selection allowing their descendents to quickly rival Earthly trilobites in terms of diversity. Burrowers, filter-feeders, and hunters exist, and a few forms have even overcome the challenge of moving to freshwater, and land. And with trilobites having repeatedly become pelagic before, it was truly inevitable that a few PD Ta. lineages would adapt to this way of life in their new home. The following is a selection of three such clades, only a part of PD Ta. trilobite diversity.

Speculative Evolution -> The Tetrarch (7)
Three unrelated, pelagic, PD Ta. trilobites. To scale, at left and right, are a Blue-Gray Oarpede and Singlespine Rodfish. Below, greatly magnified, is a Yellow Trident Cannuline.

The Oarpedes

The largest and most generalized of the common pelagic trilobites, Oarpedes are derived members of the order Phacopina. Arising early on as small, planktonic filter-feeders which swam belly-up, increased competition caused larger, faster, right-side up forms to replace their relatives. Selection for streamlining has resulted in effacement, a condition in which ridges, bumps, and sutures are externally reduced or absent, known in several Earthly trilobite clades. Ranging from half an inch to the four inches of a few deepwater giants, Oarpedes are visually-oriented omnivores, using specialized oral limbs to manipulate food, which can be phytoplankton, zooplankton, macroscopic algae, invertebrates, carrion, or detritus depending on the species. Spawning pelagically, they drift as a protaspis, molting repeatedly before reaching adulthood at a few months of age, more in polar and deepwater species. Adult Oarpedes school for safety, and many kinds associate with the bottom despite moving primarily in open water, making them analogous to Penaeid prawns. However, Oarpedes are not typically of great importance as prey items, outnumbered by ecologically similar species, such as other trilobites and Felters.

The Cannulines

Tiny, rarely more than a centimeter, Cannulines are neotenic members of Asaphida, maturing in a modified protaspis stage, with some adult traits. Their long, rigid bodies lack articulated segments, inrolled margins forming a tube, hiding their limbs and underside. By beating their feathery legs, they can form a current that enters the tube at their head end, and exits at their rear, propelling them forward at speed. However, they are mostly planktonic, and typically only move in this way when they detect a predator with their disproportionately long pair of antennae, their tiny, internal eyes more useful for determining the time of day. When feeding, usually on diatoms and other phytoplankton, Cannulines reverse the direction of their legs' motion, drawing water into the back of the tube, up their body, to their mouth. This reversed motion also plays a part in mating, drawing sperm up to the twenty or so eggs a female holds in her tube until they are fertilized, when she releases them to float away. Cannuline larvae resemble a more typical asaphoid protaspis, taking several months and a few molts to reach adulthood. Present worldwide, but not in great density, and only at the very surface of the ocean, they are overshadowed by ecologically similar copepods.

The Rodfish

The ancestor of Rodfish was a Proetidan that developed a long body in order to increase agility on it's brief trips into the water column. These forays became longer and longer, and true Rodfish, appearing thirty-five million years ago, are entirely pelagic. Specifically, they are mesopelagic, spending the day at around two hundred meters in all warm oceanic waters. This environment has warped the classic trilobite body plan considerably. Rodfish bodies are much longer than they are wide, roughly cylindrical, and lined by paddle-like legs that wave to move the animal. The gnathobases (first segments) of the front pairs of limbs are spiny and exaggerated, enabling their owner to firmly grasp the small invertebrates they hunt. Allowing them to detect this prey, as well as their predators, Rodfish eyes are relatively massive, spherical structures, soaking up the dim light from every direction. Being able to see directly behind themselves has another advantage: a frightened individual can reverse, and swim backwards with as much speed and agility as forwards. This behavior is especially striking when an entire school is alarmed, and appears to bounce off of an invisible wall and away from the threat. Rodfish are vertical migrants, rising to the surface at night, and descending again once the sun rises. It is during these ascents that Rodfish spawn, releasing their eggs under the cover of darkness. The Rodfish protaspis hatches at a relatively late stage, and possesses a gas-filled cavity at the very front of it's head, before the glabella. Successive molts see the cavity shrink, and once the Rodfish reaches adulthood, it is completely gone, letting the animal descend to it's adult habitat.


--------------------

You can also find me on DeviantArt and Twitter!

PM

Pippin

Posted: Apr 10 2019, 04:14 PM

Speculative Evolution -> The Tetrarch (9)
Adolescent

Speculative Evolution -> The Tetrarch (10) Group: Members
Speculative Evolution -> The Tetrarch (11) Posts: 198
Speculative Evolution -> The Tetrarch (12) Joined: 30-August 18

'); }if("Male" != "") { document.write('Gender:

Male

'); }if("" != "") { document.write('Location:'); }if("Terraformed and Alternate Planets" != "") { document.write('Field of Expertise:

Terraformed and Alternate Planets

'); }if("“When I’m dead just throw me in the trash.” Danny DeVito" != "") { document.write('Favorite Quote:

“When I’m dead just throw me in the trash.” Danny DeVito

'); }

Awards: None


Speculative Evolution -> The Tetrarch (13)

Hurray, a new Tetrarch update! I must say this is one of my favorite projects on the forum, what with the diversity and genuinely unusual creatures.

PM

Weirdfish

Posted: Apr 11 2019, 05:10 PM

Speculative Evolution -> The Tetrarch (15)
Squillious Squimber

Speculative Evolution -> The Tetrarch (16) Group: Members
Speculative Evolution -> The Tetrarch (17) Posts: 146
Speculative Evolution -> The Tetrarch (18) Joined: 21-August 18

'); }if("Deuterostome" != "") { document.write('Gender:

Deuterostome

'); }if("Wisconsin" != "") { document.write('Location:

Wisconsin

'); }if("Hahaha "expertise"" != "") { document.write('Field of Expertise:

Hahaha "expertise"

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: None


Speculative Evolution -> The Tetrarch (19)

The Felters

Speculative Evolution -> The Tetrarch (20)
A Borric Felter, displaying typical Felter anatomy.

The term “forage fish” applies to a great number of different groups on Earth, united by being small, schooling, open-water fish that are important food sources to larger predators. Any given school of forage fish on Theatra, however, are very likely to be Felters. Taking off ecologically about ten million years after the Tetrarch began, the derived, PD Ta. conodonts began to monopolize the niche. Other, similar fish, derived pipefish especially, which had not been in the niche for long, were outcompeted or forced to specialize. It wasn't any particular super-powered trait that let the Felters take over, merely superb efficiency. Like their ancestors, most Felters have short lifespans, just a month, and their single spawning session produces enough eggs to completely flood the ecosystem if it weren't for their many predators. Larvae drift at the surface, part of the plankton, joining together in juvenile schools, only ever descending further than about thirty feet once they are almost ready to breed. Beyond their life history, Felters have very rudimentary, cartilaginous skeletons, enabling an extremely rapid growth rate, and the combination of a long, undulating body and a scissor-shaped caudal fin makes their swimming very cheap, energetically. The lack of paired fins limits maneuverability, but a swim bladder, independently developed, maintains lift. Finally, Felters are obligate ram ventilators, relying on forward movement to breathe. Though an individual Felter is not terribly fast, and is not as intelligent or agile as the few jawed fish sharing their niche, their great schools provide some defense, letting the collective forage and evade danger as cost-effectively as possible. Ecological perfection like this means that most Felters do not stray much from the norm, but there are exceptions.

In terms of diet, most species are similar to Earthly forage fish, relying on planktonic crustaceans, often to the extent that they exclude even large filter-feeders from this food source. A clade of polar Felters, however, are the Tetrarchian analogues to krill, feeding mostly on algae. These, the Ice Felters, hold the Tetrarchian record for greatest population size of any vertebrate species, shared among several species from both the Aquilic and Notic oceans. Smaller than average, only two inches, Ice Felters are named for their transparency, not their habitat, which they are even more common in than other Felters, already a vital pillar of the ecosystem. Ice Felters are so ubiquitous that entire species rely on them completely for food, almost becoming a constant part of the environment rather than just animals.

The poles are also home to the largest Felters, the very largest living in the twilight zone at the south pole. The Giant Shark Felter is a foot long, living in relatively small schools, feeding on large copepods. In turn, they are a common prey item for deepwater predators, and they are usually only seen at the surface as rafts of dead individuals, having just spawned after an unusually long life of six months. The other end of the spectrum in many more ways than size, Fry Felters are the most miniscule of the group. Just over half an inch, Fry Felters live as plankton in warm, shallow waters in the Venusic ocean. Though they school like any Felter, they cannot fight a current, and have to remain in protected coves and lagoons or risk being swept around and separated, very unusual for their typically oceanic clade. Feeding on algae and small zooplankton, Fry Felters are sparser than other types, requiring ideal conditions to form a school long enough to spawn, despite it only taking a couple weeks. Once the breeding swarm dies, they are often close enough to shore to wash up before sinking, and a strandline of tiny, dead fish forms, providing food for resourceful seadoves and scavenging insects.

As PD Ta. fish, Felters of course having gliding representatives, the Flechettes. Living in the Notic and Apollonic oceans, Flechettes are average-sized to large Felters which feed on crustaceans like most, and are in fact the most common Felters where they occur. Gliding Felters likely would have evolved many more times if they possessed paired fins, but a Flechette's “wings” are actually novel structures. Attached above the gill openings, and usually tucked against the body, the twin flaps extend into triangular fins like those of a squid when needed, but allow only relatively short flights of under one hundred feet. Even this is spectacular when a large school is spooked, several thousand fish darting over the surface before hitting the water again.

This post has been edited by DINOCARID: Apr 12 2019, 09:23 AM


--------------------

You can also find me on DeviantArt and Twitter!

PM

GlarnBoudin

Posted: Apr 11 2019, 08:12 PM

Speculative Evolution -> The Tetrarch (22)
Prime Specimen

Speculative Evolution -> The Tetrarch (23) Group: Members
Speculative Evolution -> The Tetrarch (24) Posts: 744
Speculative Evolution -> The Tetrarch (25) Joined: 20-August 18

'); }if("" != "") { document.write('Gender:'); }if("" != "") { document.write('Location:'); }if("" != "") { document.write('Field of Expertise:'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: 1

Speculative Evolution -> The Tetrarch (26)


Speculative Evolution -> The Tetrarch (27)

Simple, yet elegant. I like 'em! Not often you see conodont spec here.


--------------------
Projects:

Retrozoic Park: Bringing back the post in more ways than one.

Projects in Progress:

Spoiler: click to toggle

PMEmail

Beetleboy

Posted: Apr 12 2019, 01:57 AM

Speculative Evolution -> The Tetrarch (29)
Myceliomancer

Speculative Evolution -> The Tetrarch (30) Group: Members
Speculative Evolution -> The Tetrarch (31) Posts: 1085
Speculative Evolution -> The Tetrarch (32) Joined: 21-August 18

'); }if("He/they" != "") { document.write('Gender:

He/they

'); }if("Wales - probably in a woodland or reedbed looking at mushrooms" != "") { document.write('Location:

Wales - probably in a woodland or reedbed looking at mushrooms

'); }if("Mycology and ecology (especially tropical rainforests and especially Indonesian)" != "") { document.write('Field of Expertise:

Mycology and ecology (especially tropical rainforests and especially Indonesian)

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: 1

Speculative Evolution -> The Tetrarch (33)


Speculative Evolution -> The Tetrarch (34)

Loving the recent updates!


--------------------

--- a shambling writhing figure of mycelium and earthworms ---

FourEyesIsAFish

Posted: Apr 12 2019, 06:54 AM

Speculative Evolution -> The Tetrarch (36)
Sentient Anablepidae, who finally made something good for once

Speculative Evolution -> The Tetrarch (37) Group: Sagan 4 Member
Speculative Evolution -> The Tetrarch (38) Posts: 1128
Speculative Evolution -> The Tetrarch (39) Joined: 4-January 19

'); }if("Male" != "") { document.write('Gender:

Male

'); }if("" != "") { document.write('Location:'); }if("Marine Biology" != "") { document.write('Field of Expertise:

Marine Biology

'); }if(""In the absence of proper data, speculate wildly" - Mark Witton" != "") { document.write('Favorite Quote:

"In the absence of proper data, speculate wildly" - Mark Witton

'); }

Awards: None


Speculative Evolution -> The Tetrarch (40)

There's something in this post which no one has noticed...

CONODONT KRILL.

10/10 would read again.


--------------------

s p e c u l a t i v e e v o l u t i o n

Quotes

PM

Weirdfish

Posted: Apr 12 2019, 01:36 PM

Speculative Evolution -> The Tetrarch (42)
Squillious Squimber

Speculative Evolution -> The Tetrarch (43) Group: Members
Speculative Evolution -> The Tetrarch (44) Posts: 146
Speculative Evolution -> The Tetrarch (45) Joined: 21-August 18

'); }if("Deuterostome" != "") { document.write('Gender:

Deuterostome

'); }if("Wisconsin" != "") { document.write('Location:

Wisconsin

'); }if("Hahaha "expertise"" != "") { document.write('Field of Expertise:

Hahaha "expertise"

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: None


Speculative Evolution -> The Tetrarch (46)

I tried to make the felters not only a twist on an otherwise slightly uninteresting category of fish, but a twist on the actual ecosystem. Judging by your responses, I did it right!


--------------------

You can also find me on DeviantArt and Twitter!

PM

Weirdfish

Posted: Apr 22 2019, 01:56 PM

Speculative Evolution -> The Tetrarch (48)
Squillious Squimber

Speculative Evolution -> The Tetrarch (49) Group: Members
Speculative Evolution -> The Tetrarch (50) Posts: 146
Speculative Evolution -> The Tetrarch (51) Joined: 21-August 18

'); }if("Deuterostome" != "") { document.write('Gender:

Deuterostome

'); }if("Wisconsin" != "") { document.write('Location:

Wisconsin

'); }if("Hahaha "expertise"" != "") { document.write('Field of Expertise:

Hahaha "expertise"

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: None


Speculative Evolution -> The Tetrarch (52)

After a bit of deliberation, I've decided to remove the quillworts and horseshoe crabs from the colonist list. They were artifacts of a mindset in which I added anything interesting, and they don't stimulate my imagination the way that the rest of the list does, only adding another variable, another thing to keep track of. So, anything they would've done will now pad out the Tetrarch's diversity in the form of something else's descendants!


--------------------

You can also find me on DeviantArt and Twitter!

PM

Beetleboy

Posted: Apr 23 2019, 04:26 AM

Speculative Evolution -> The Tetrarch (54)
Myceliomancer

Speculative Evolution -> The Tetrarch (55) Group: Members
Speculative Evolution -> The Tetrarch (56) Posts: 1085
Speculative Evolution -> The Tetrarch (57) Joined: 21-August 18

'); }if("He/they" != "") { document.write('Gender:

He/they

'); }if("Wales - probably in a woodland or reedbed looking at mushrooms" != "") { document.write('Location:

Wales - probably in a woodland or reedbed looking at mushrooms

'); }if("Mycology and ecology (especially tropical rainforests and especially Indonesian)" != "") { document.write('Field of Expertise:

Mycology and ecology (especially tropical rainforests and especially Indonesian)

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: 1

Speculative Evolution -> The Tetrarch (58)


Speculative Evolution -> The Tetrarch (59)
QUOTE (DINOCARID @ Apr 22 2019, 01:56 PM)
After a bit of deliberation, I've decided to remove the quillworts and horseshoe crabs from the colonist list. They were artifacts of a mindset in which I added anything interesting, and they don't stimulate my imagination the way that the rest of the list does, only adding another variable, another thing to keep track of. So, anything they would've done will now pad out the Tetrarch's diversity in the form of something else's descendants!

Nice, I feel like this is the right decision. Although it would have been neat to see horseshoe crab spec, I totally get why you’ve done this - I always like seeded worlds best when they have the smallest possible amount of introduced organisms.


--------------------

--- a shambling writhing figure of mycelium and earthworms ---

FourEyesIsAFish

Posted: Apr 23 2019, 07:07 AM

Speculative Evolution -> The Tetrarch (61)
Sentient Anablepidae, who finally made something good for once

Speculative Evolution -> The Tetrarch (62) Group: Sagan 4 Member
Speculative Evolution -> The Tetrarch (63) Posts: 1128
Speculative Evolution -> The Tetrarch (64) Joined: 4-January 19

'); }if("Male" != "") { document.write('Gender:

Male

'); }if("" != "") { document.write('Location:'); }if("Marine Biology" != "") { document.write('Field of Expertise:

Marine Biology

'); }if(""In the absence of proper data, speculate wildly" - Mark Witton" != "") { document.write('Favorite Quote:

"In the absence of proper data, speculate wildly" - Mark Witton

'); }

Awards: None


Speculative Evolution -> The Tetrarch (65)

I have a quick question: What evidence do you have that conodonts didn't have long lives? I would love to know how you know, if you know what I'm saying.


--------------------

s p e c u l a t i v e e v o l u t i o n

Quotes

PM

Seal

Posted: Apr 23 2019, 08:16 AM

Speculative Evolution -> The Tetrarch (67)
You have my seal of approval.

Speculative Evolution -> The Tetrarch (68) Group: Members
Speculative Evolution -> The Tetrarch (69) Posts: 1224
Speculative Evolution -> The Tetrarch (70) Joined: 21-August 18

'); }if("Male" != "") { document.write('Gender:

Male

'); }if("Ireland" != "") { document.write('Location:

Ireland

'); }if("Xenobiology" != "") { document.write('Field of Expertise:

Xenobiology

'); }if(""Your inability to understand evolution is not evidence against it."" != "") { document.write('Favorite Quote:

"Your inability to understand evolution is not evidence against it."

'); }

Awards: 4

Speculative Evolution -> The Tetrarch (71) Speculative Evolution -> The Tetrarch (72) Speculative Evolution -> The Tetrarch (73) Speculative Evolution -> The Tetrarch (74)


Speculative Evolution -> The Tetrarch (75)
QUOTE (FourEyesIsAFish @ Apr 23 2019, 12:07 PM)
I have a quick question: What evidence do you have that conodonts didn't have long lives? I would love to know how you know, if you know what I'm saying.

Very small size and presumably low intelligence?


--------------------

Nemo, a lush, oxygen-rich world home to fire-breathing hexapods, lithotrophic megafauna, giant balloons, muscular plants and steel-boned beasts.

Katurra, a terraformed world seeded only with African flora and fauna.

Encyclopaedia Confictura, Earth, but not as we know it - inhabited by hundreds of mythical creatures from practically every culture in the world, from Sverðhvalurs to Qasogonagas.

Project ideas

PM

Weirdfish

Posted: Apr 23 2019, 08:35 AM

Speculative Evolution -> The Tetrarch (77)
Squillious Squimber

Speculative Evolution -> The Tetrarch (78) Group: Members
Speculative Evolution -> The Tetrarch (79) Posts: 146
Speculative Evolution -> The Tetrarch (80) Joined: 21-August 18

'); }if("Deuterostome" != "") { document.write('Gender:

Deuterostome

'); }if("Wisconsin" != "") { document.write('Location:

Wisconsin

'); }if("Hahaha "expertise"" != "") { document.write('Field of Expertise:

Hahaha "expertise"

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: None


Speculative Evolution -> The Tetrarch (81)
QUOTE
I have a quick question: What evidence do you have that conodonts didn't have long lives?

A study by Przemyslaw Swis, in the journal Historical Biology. It examines the population dynamics of Alternognathus based on the growth of their teeth, and estimates a lifespan of about a month. Even if this doesn't hold true for conodonts as a whole, the Felters are an odd case, and it was vital to my vision of them that they have very short lives.

This post has been edited by DINOCARID: Apr 23 2019, 08:36 AM


--------------------

You can also find me on DeviantArt and Twitter!

PM

FourEyesIsAFish

Posted: Apr 23 2019, 08:44 AM

Speculative Evolution -> The Tetrarch (83)
Sentient Anablepidae, who finally made something good for once

Speculative Evolution -> The Tetrarch (84) Group: Sagan 4 Member
Speculative Evolution -> The Tetrarch (85) Posts: 1128
Speculative Evolution -> The Tetrarch (86) Joined: 4-January 19

'); }if("Male" != "") { document.write('Gender:

Male

'); }if("" != "") { document.write('Location:'); }if("Marine Biology" != "") { document.write('Field of Expertise:

Marine Biology

'); }if(""In the absence of proper data, speculate wildly" - Mark Witton" != "") { document.write('Favorite Quote:

"In the absence of proper data, speculate wildly" - Mark Witton

'); }

Awards: None


Speculative Evolution -> The Tetrarch (87)
QUOTE (DINOCARID @ Apr 23 2019, 08:35 AM)
QUOTE
I have a quick question: What evidence do you have that conodonts didn't have long lives?

A study by Przemyslaw Swis, in the journal Historical Biology. It examines the population dynamics of Alternognathus based on the growth of their teeth, and estimates a lifespan of about a month. Even if this doesn't hold true for conodonts as a whole, the Felters are an odd case, and it was vital to my vision of them that they have very short lives.

Cool! I was just wondering.


--------------------

s p e c u l a t i v e e v o l u t i o n

Quotes

PM

Weirdfish

Posted: Jun 2 2019, 05:39 PM

Speculative Evolution -> The Tetrarch (89)
Squillious Squimber

Speculative Evolution -> The Tetrarch (90) Group: Members
Speculative Evolution -> The Tetrarch (91) Posts: 146
Speculative Evolution -> The Tetrarch (92) Joined: 21-August 18

'); }if("Deuterostome" != "") { document.write('Gender:

Deuterostome

'); }if("Wisconsin" != "") { document.write('Location:

Wisconsin

'); }if("Hahaha "expertise"" != "") { document.write('Field of Expertise:

Hahaha "expertise"

'); }if("" != "") { document.write('Favorite Quote:'); }

Awards: None


Speculative Evolution -> The Tetrarch (93)

Mountain-Makers

Location

In the northern Venusic ocean, just south of the Ceresian coast, a curious-looking fish swims steadily over a diverse seameadow. Illustrans's light beams strongly through the thirty feet of clear blue water to bathe the seagrass and algae, growing densely between patches of white sand. The diamond-shaped fish is a super-saturated navy blue in the strong illumination, white and black fin borders flashing as it's dorsal and anal fins propel it through the water, steered by it's tail. Though a bounty of invertebrates and greens are spread out under the Peacock Switchspine, it seems to have a goal in mind as it passes over them. The tall, whip-like, PD Ta. seagrasses it continues between slow the movement of the seawater, allowing sediment to precipitate, their neighbors, especially the PD Fi. Ones, stabilizing the substrate with their extensive roots. This duality is a hallmark of climax communities in tropical seameadows, the ecosystem becoming more diverse and stable as it forms. In many cases, this ecosystem engineering even allows a whole new habitat to flourish...

As the Switchspine enters the shadow of a fifteen-foot cliff, it begins to ascend. Though obscured by a thick layer of encrusting algae and bryozoans, it is clear that the rolling, bumpy, pitted wall is alive. Thinner patches reveal it's internal structure, graceful, horn-like, conical shells stacked atop one another, each one's flower-like top emerging from the growth at the surface. The many tentacles, powder blue and sea green, radiate in clumps from pores in the top of the shell, a hole in the middle of each rosette. Cresting the ridge, the PD Ex. fish emerges back into the sunlight, a complex landscape spread out before it, miniature mountains, towers, crevasses, and caves, all covered in the diverse floral crowns, colored in bright neon shades by various epibionts, and teeming with small fish and invertebrates. A small shell, half a foot rather than two, and not yet obscured by the ubiquitous crust, projects from the summit of a bluff. The young individual displays a Blue Aster Orolog's anatomy clearly, and hints at their rather cryptic identity as PD Ex. bivalves. The majority of the shell, a cone attached at the narrow end, is the Orolog's right valve, the small “cap” from which the tentacles emerge, the opposite, it's left. The asymmetry extends to structure as well as shape, the solid right valve contrasted by a branching network of canals leading from the left valve's inner margin up to the outer surface. Mantle tissue extends in hollow tentacles through these canals, the ends emerging from the shell through the pores, flaring and splitting into multiple thinner tentacles. Peppering the cells just under the outer layer of these tentacles, are mutualistic, PD Ex. dinoflagellates, zooxanthellae. With a safe, well-lit home, they can afford to share much of their photosynthetic products, sugars and amino acids, with the rudist they live in.

Seawater streams over the Orolog, the reef ventilated by wave action. As well as providing surface area to bask it's microscopic partners, it's tentacles slow water movement, trapping phytoplankton, which are drawn into the left valve's canals by the motion of cilia lining their walls. Once inside, the motes of algae are transported through the canals, which join together into progressively larger tubes until they open into the mantle cavity. At this point, they are drawn to the mouth and eaten, only accounting for a small part of the Orolog's energy needs, but providing nutrients that the mollusc cannot derive from it's zooxanthellae, and those that the zooxanthellae cannot manufacture on their own. The way in which these two very different organisms support each other, lending their strengths and compensating for the other's weaknesses, allows Orologs to grow relatively quickly, becoming the dominant reef-formers in ideal conditions. Ideal conditions only made possible by the extensive seameadows in the area. The Venusic ocean is characterized by high salinity and temperatures, and low oxygen, the great abundance of life on the coasts only made possible by greater water motion and nutrients from inland. Predictably, the mouths of large rivers are important sites, and affect even relatively distant, down-current waters. However, they damage the high-salinity, crystal-clear conditions that Orologs grow best in, which is where the seagrass duo comes in. Cleaning the water and enriching the local flora and fauna, a seameadow is usually a prerequisite for the sensitive Orologs to successfully form a reef in the Venusic ocean.

Speculative Evolution -> The Tetrarch (94)

Now searching from crest to crest, the Switchspine stops at a larger Orolog of the same species, which flinches at it's touch, drawing it's tentacles inwards in a sharp jerk. Though they are simple, the numerous eyespots lining it's mantle rim, peeking out from between it's two valves, allow it to react early to danger. Unfazed, the fish circles around and finds it's target, a pair of slots, openings for siphons which are hidden under the bush of photosynthetic tentacles when not withdrawn. Placing it's small mouth on the slot in the left valve into which the large siphon retracted, it vibrates it's slender jaw against the shell in bursts, almost thirty beats a second. After a few bursts, the Orolog suddenly lets it's guard down, it's plume of tentacles and siphons sliding back out a small ways. Placing it's beak-like mouth in the flared end of the larger siphon, the Switchspine pumps it's gills, and the suction prompts a series of rhythmic contractions, leaving the fish with a mouthful of mucus. The fish sucks up one last wisp of slime before moving on. Seeking out another Blue Aster Orolog by it's distinctive scent, it scares this one too, but seems to reassure it with the odd jaw-buzzing behavior. As this Orolog re-extends it's appendages, it spreads it's tentacles wide, forcing the Switchspine to brush past them in order to access it's half-retracted siphon, covered by the edge of the crown. As it does, some sticky mucus is smeared onto them, having clung to it's snout after it's first meal. This specimen spasms once, and offers up a glob of mucus.

Repeatedly flexing it's jaws, the Switchspine clears it's mouth of goo, and takes off after another of the blue fish farther down the slope, chasing it out of sight. The second Orolog, now fully relaxed and basking it's tentacles in the light at full extent, is a female, and the mucus left behind on her tentacles is more than coincidental. Compounds in the substance stimulate cilia on the tentacles' surface to slowly move it down to their base pore. Pulled through the canals, it ends up in her mantle cavity as if it were food. Instead of her mouth though, it is deposited in a segregated space, full of small, unfertilized eggs. Spermatozoa in the male's mucus is activated by a substance on the eggs' surfaces, and they are soon fertilized. And so, without wasting semen and eggs, the two sessile bivalves have successfully brought their gametes together. This clever reproductive strategy evolved twenty-five million years ago, and as all great innovations do, it started as an accident.

A pair of ancient species, Switchspine and Orolog, coexisted, and as more basal species from both groups still do, the derived porcupinefish mostly grazed algae from the reef, and the rudists used jets of mucus from their larger siphon, usually used for excreting feces, to foil their shell-crunching predators. When Switchspines ate algae from the Orologs' shells, they often got a face-full of defensive secretions. The toxins in this “ink” were derived from those in the phytoplankton that the Orologs fed on, but as hardy herbivores, the Switchspines were immune to very similar compounds, rendering it ineffective at most. And when an Orolog's mantle cavity was full of sperm, it became not only ineffective, but nutritious, and the intelligent fish caught on. If an unsatisfied fish went on to repeat the trick on another individual, it usually left at least a little sperm on and around it, to it's advantage if it was a female. Over time, the Orologs ditched the toxins and upped the protein, encouraging the radical new diet in the fish. Even females laced their once-defensive slime with enticing scents and rewarding nutrients in order to attract more potentially sperm-bearing Switchspines, which were adapting to their additional food item. A trusting Orolog is an easily-eaten one though, so as the relationship developed, the two very different animals developed a password. Adapted from the jaw movements used to suck up food, jaw-buzzing is a unique stimulus that tells a frightened Orolog that it's visitor does not intend to harm it. Processing that information, and distinguishing it from dangerous imitators, encouraged larger brains, and though they certainly cannot form plans or use tools, an Orolog is a great deal smarter than a coral polyp. Finally, to prevent wasteful cross-fertilization, which almost never results in viable eggs, Orolog species whose ranges overlap have distinct spawning periods, which they stagger. For another week or so, it is the Blue Aster Orolog's turn, and they advertise it by releasing a unique odor into the water.

Effective and distinctive as it may be, this reproductive trait is not the only thing setting Orologs apart. These modern species share their photosynthetic ways with ancestors that existed long before the Switchspine symbiosis, which also brooded their eggs. Unusually large for a bivalve's, she will retain her eggs, supplied with a store of lipids and proteins, until the larvae inside have metamorphosed, with tiny valves of their own. Once they have completed their incubation, the female will implement their symbiosis once more. Entering a second receptive window, she will feed visiting Switchspines as before, but this time, the fish will leave with more than a full stomach. She will aim her smaller siphon, usually used for ejecting debris as pseudofeces, and fire a string of adhesive gel at her diner, a portion of her brood suspended inside. When the Switchspine goes about it's business, defending it's territory and the Orologs within from others, it will attempt to remove the unsightly smear. Rubbing against shells and other surfaces, the eggs will be deposited on them, and the agitated gel matrix will allow seawater in, stimulating them to hatch. She will repeat this ploy until she runs out of eggs, around half a million of them per season, ensuring that some spat (freshly-attached spawn) will make it through their dangerous younger years. Under one percent survive to adulthood, but those that do can live to nearly a century, invulnerable to all but the most specialized predators, raising the reef by one more shell.


--------------------

You can also find me on DeviantArt and Twitter!

PM

CeratosaurusKingV2

Posted: Jun 2 2019, 11:07 PM

Speculative Evolution -> The Tetrarch (96)
GatorRaid

Speculative Evolution -> The Tetrarch (97) Group: Members
Speculative Evolution -> The Tetrarch (98) Posts: 66
Speculative Evolution -> The Tetrarch (99) Joined: 20-August 18

'); }if("I'm a Dude" != "") { document.write('Gender:

I'm a Dude

'); }if("Your mother's basement" != "") { document.write('Location:

Your mother's basement

'); }if("IDK " != "") { document.write('Field of Expertise:

IDK

'); }if(""No Mistakes, Only happy accidents" -Bob Ross" != "") { document.write('Favorite Quote:

"No Mistakes, Only happy accidents" -Bob Ross

'); }

Awards: None


Speculative Evolution -> The Tetrarch (100)

Another good update


--------------------

Current List of Projects:

The Reserve - A seeded world project about a variety of extinct organisms

PM

0 User(s) are reading this topic (0 Guests and 0 Anonymous Users)

0 Members:

« Next Oldest | Evolutionary Continuum | Next Newest »

Powered by Invision Power Board (Jcink.com Forum Hosting) © 2024 IPS, Inc.
Page creation time: 0.0217

· Privacy Policy

Speculative Evolution -> The Tetrarch (2024)
Top Articles
Latest Posts
Recommended Articles
Article information

Author: Pres. Lawanda Wiegand

Last Updated:

Views: 5287

Rating: 4 / 5 (71 voted)

Reviews: 94% of readers found this page helpful

Author information

Name: Pres. Lawanda Wiegand

Birthday: 1993-01-10

Address: Suite 391 6963 Ullrich Shore, Bellefort, WI 01350-7893

Phone: +6806610432415

Job: Dynamic Manufacturing Assistant

Hobby: amateur radio, Taekwondo, Wood carving, Parkour, Skateboarding, Running, Rafting

Introduction: My name is Pres. Lawanda Wiegand, I am a inquisitive, helpful, glamorous, cheerful, open, clever, innocent person who loves writing and wants to share my knowledge and understanding with you.