Comb Worm

While most organisms in the early Lemuran period where largely restricted to remaining in close proximity to the benthic zones of the continental shelves, a particularly basal member of Olcanimalia - commonly referred to as a comb worm - managed to develop both a filter feeding system and a means of locomotion throughout the water column. With additional minor adaptations to its skin on certain portions of its body allowing it to anchor itself to the substrate as well, which is evident in trace fossils, it stands as one of the only organisms present in the early Lemuran that managed to achieve a semblance of cosmopolitan distribution.

Artwork done by Futaba Jelenic

Basic Information

Anatomy

Comb worms, being among the earliest members of olcanimalia to diverge, retain numerous basal characteristics and lack the features of most adult motile animals on Vulgar. Most notably of all of which is their lack of muscle tissues of any kind whatsoever, as the species' lineage diverged from the rest of olcanimalia before these tissue types evolved. Thus, they have had to employ other means of moving in their environment as well as conducting internal bodily functions. The main way they do this is with cilia, which they organize into combs along their bodies like comb jellies on Earth. This allows them to move through the water column without the use of muscle tissues.

The have a blind gut with an opening on the top of their bodies mistakenly referred to colloquially as their back, which is responsible for both digestion, absorption of nutrients, and expulsion of waste. Gas exchange occurs across the majority of their skin with the exception being on their underside when it is coated with adhesives. Their "tails" are actually a sort of pseudo-pod that they can use to help stick themselves to the seafloor, use as a trunk for sitting upright into the water column, and for grasping particulate floating in the water to be transported to the mouth. The entire tail is able to secrete adhesive enzymes and is covered in small cilia hairs that are used for trapping particulate when used for filter feeding. The "head" of the organism is actually just a location for vital organs to rest - those that are known to exist here from impression fossils are the reproductive organs, two antennae used for "tasting" the water column for the presence of food, and a primitive liver.

Additionally, the comb worm is known to have been able to secrete adhesive enzymes and mucus on the underside of its body in addition to its tail. From fossilized remains, it is believed that this was so that the creature could stick itself to the seafloor without the use of muscle tissues necessary to grip the microbial mat. This would have allowed the creature to filter feed with its tail while avoiding expending energy on locomotion in the water column, and was likely their default mode of life where it was possible.

Genetics and Reproduction

Comb worms are known to have possessed their reproductive organs in their pseudo-head, and fossil evidence indicates that the organisms reproduced by broadcast spawning. The organisms could reproduce in one of two ways - asexually or sexually. Sexual reproduction was facilitated via. the release of male gametes into the water column, which then would, upon contact with the skin of another comb worm, attempt to fertilize any female gametes present before the new zygotes where released into the water column. Alternatively, during conditions of low stress, the process of meiosis was apparently skipped in the reproductive organs, resulting in the creation of spores that could be released into the water and grow into adult organisms without the need for fertilization.

Growth Rate & Stages

Unlike other species that the comb worms shared their ecosystems with, there is very little fossil evidence regarding the growth stages and juvenile forms comb worms took early in life. Based on what evidence there is, however, it is currently believed that comb worms likely underwent a planktonic larval phase shortly after fertilization, before developing into a microscopic miniature adult. This miniature adult would grow until it reached adult sizes, and specimens discovered so far are usually considered to be "adults" if they are larger than 10 centimeters in length.

Dietary Needs and Habits

Comb worms are believed to have primarily subsisted on filter feeding, with filtered particulate being deposited into the mouth for digestion. However, it is also entirely plausible that their simple nervous system and instinct-driven behavior may not have distinguished between large amounts of particulate being deposited into the gut and an unlucky organism that got stuck there by happenstance.

General Information

Time Period: Lemuran Period
Scientific Name: Ctenovermis rediculam
Kingdom: Olcanimalia
Phylum: Somactenamysa
Lifespan: 6 Vulgur years
Average Height: 12 cm
Average Length: 31 cm
Habitat: Cosmopolitan Distribution