Shieldneck

The mass extinction brought with it a new radiation of predators that many of the more primitive species have to adapt to. Descendants of Xenoeuly kirbyi have always had a tendency to develop thick chitinous armor to protect themselves from predation. Though none have gone to the extreme of the shieldnecks. Thick armored plates and suction cup like feet on their hind legs make a difficult meal for even the most determined of predators. Their most alarming feature though is when they fully extend their long “necks” composed of softer, more flexible segments. This long and flexible neck allows the Shieldneck to feed on hard to reach Retinalphytes even so much as to reach out of the water to feed on Retinalphytes on riverbanks. These adaptations have led to a population explosion in the freshwater tolerant Shieldnecks, while salt water populations are limited to the fields of Sargrasso plants. [creature design by Saurusblood]

Basic Information

Anatomy

Shieldnecks have a segmented body that can be divided into four main types of segment Identified by their physical features and function. The first is segment type is the head, the majority of which is covered in a large diamond shaped chitinous shell plate. The plate is one solid color except in the regions that cover the eyes where it is translucent as not to obstruct vision. The ventral side of the head has a circular soft jaw and a pair of chitin covered limbs used to masticate plant material. The mouth is surrounded by chemoreceptors within the skin. The second type of segments will be referred to as the exterior neck and consists of four individual segments. These cylindrical segments are very flexible and each possess a pair of eyes and chitin covered limbs. The third type of segments are referred to as the interior neck and consist of 3 distinct segments who increase in size until they reach the final segment type. They resemble the exterior neck segments but lack any eyes. In their place are feather like gill structures housed between their non functioning chitinous limbs. The interior neck also houses the largest muscles in the shieldneck’s body are capable of fully retracting the exterior neck segments in 1 earth second. The final segment type is referred to as the shell segments consisting of another 3 distinct segments. The Shell segments are the most diverse and have been given three distinct names of the primary shell, secondary shell and tertiary shell. The primary shell is the largest and is covered by two large v shaped plates that extend over the interior neck segments. The pair of limbs are covered in a much more flexible chitin covering and are the largest. The ends of these limbs are shaped like suction cups and will grip onto smooth surfaces. Internally the primary shell contains the shieldneck’s gut. The secondary shell is a smaller version of the primary shell though internally it contains the reproductive organs. The tertiary shell is reduced even further and consists of only one triangular dorsal plate and is the location of the shieldneck’s cloaca.

Genetics and Reproduction

Shieldnecks are hermaphrodites. When the waters they live in warm they will begin searching for a mate. Once a mate is found they will deposit a mucus covered sac of gametes that will be ingested by the mate. The mucus membrane is digested while the gametes travel into the ovipositor. After 2 local days the shieldneck will produce an egg sack with on average 10-20 eggs that the shieldneck will carry with it under the tertiary shell.

Growth Rate & Stages

After hatching from their eggs larval shieldnecks are free swimming and resemble the ancestral Xenoeuly kirbyi. They will feed by filtering substrate for 120 local days at which point they will bury themselves under the substrate. For an additional 30 local days their bodies will metamorphose into miniature versions of the adult form. After 1 local year they will be large enough to breed.

Ecology and Habitats

Shieldnecks can be found in the shallow sea between Yama, Kub Shay and Artica. Feeding primarily in Sargrasso fields. There are however three distinct subspecies who live in the freshwater systems of all three of the continents in lakes, rivers and streams. The freshwater species have exploded in population due to reduced competition and less prominent predators. Aspídalaimós chrysafénios inhabits shallow reefs between Kub Shay and Yama. Aspídalaimós yamensis in habits the fresh waters of Yama. Aspídalaimós kubhayensis inhabits the fresh waters of Kub Shay. Aspídalaimós articaensis inhabits the fresh waters of Artica.

Dietary Needs and Habits

Shieldnecks feed primarily on retinalphytes but are still capable of filtering food out of the substrate.

Additional Information

Perception and Sensory Capabilities

The eyes located on the head segment have much more clear vision compared to its ancestors with limited color visibility. The eyes on the exterior neck segments are much simpler but are very sensitive to movement. The chemoreceptors around the shieldneck’s mouth are sensitive though only to objects that are close to the mouth.

Genetic Ancestor(s)

Xenoeuly kirbyi

Scientific Name

Aspídalaimós sps.

Origin/Ancestry

Xenosegmenta

Lifespan

4 local years

Average Height

2 cm

Average Length

9 cm when closes, 16 cm when fully extended

Body Tint, Colouring and Marking

Each shieldneck species has a unique coloration based on its environmental pressures. The Yamen, Artican and golden shieldneck have adapted to blend in with their surroundings by either imitating rocks or retinalphytes. The outlier seems to be the Kub Shayen shieldneck who has much more flamboyant coloration this is due to an increased need for visibility. Kub Shayen shieldnecks live much more spread out then other species and the bright colors allow them to more easily identify and find mates.

Geographic Distribution