Rose Limpet
Basic Information
Anatomy
Rose limpets are quite highly derived compared to their reef crown ancestors. The tube of the reef crown is now a shell which forms on the aboral end, which now has become a dorsal side. Motive tentacles have now merged into a single muscular foot on which the rose limpet walks in a manner similar to that of a snail on earth, even exuding a mucus like lubricant. This foot surrounds the centrally located mouth composed of eight strong tentacles each tipped in a hard calcified tooth like structure made for shredding its favorite food, carrion. Inside the organism is where the most changes have taken place. The rose limpet exhibits a slight secondary bilateral symmetry. It has only four gonads and the whole organism is either male or female. Around the aboral nephridium is a ring shaped ganglion which functions as a rudimentary brain, controlling the tentacles and the direction of the movements of the foot. What in the ancestral rose crown were motive tentacles, and in the reef crown were primarily prey capture tentacles are here used as sensory organs. They are sensitive to scent and touch, but also have a very rudimentary photosensitivity, just enough for the rose limpet to know dark from light. These may be retracted into the shell and water expelled by the foot pressing the body down, this creates a suction, and makes the entire organism difficult to detach from a rock, which is its primary form of self defense. The shell itself grows outward and down in distinct layers, and is made of silicates similar in composition to the skeleton of a sponge. Like the ancestral rose crown or like earth starfish the gut of a rose limpet is blind, and the same oriface expels waste and takes in food. It is also the orifice used to expel gametes.
Genetics and Reproduction
Rose limpets are no longer broadcast spawners. Instead they can determine the sex of a conspecific via scent, and when members of opposite sex meet they will typically mate, the female expelling a few hundred ova on the ground and then guiding the male over the deposited eggs for him to externally fertilize. Most such broods only have one or two individuals survive to adulthood or even none, but matings may occur every few local days for any given rose limpet so overall they tend to have a fairly high reproduction rate and can easily colonize new areas through this high rate of reproduction.
Growth Rate & Stages
Fertilized rose limpets will quickly grow into small larvae that resemble the ancestral rose crown, living as planktonic predators of zooplankton. As they grow they begin to be able to swim against the current, once they reach about 0.5 cm in length on the long axis, they will swim down to the substrate and fine a crevice. At this point they will undergo a bit of metamorphosis. It will grow a tiny shell and its 32 feeding tendrils will shrink in length and merge into a muscular foot. When this is done the organism will have shrunk to about 0.35 cm in length and will be a miniature adult.
Ecology and Habitats
As generalist scavengers rose limpets can be found in virtually every marine environment. In shallow waters they will also eat organisms such as jade crowns.
Additional Information
Geographic Origin and Distribution
Oceans world wide except shallow waters near Niylan.
Average Intelligence
Despite being geniuses among stephanozoans, they have only the most rudimentary brain, and are in fact completely instinct driven, being completely incapable of learning from experience.
Perception and Sensory Capabilities
The tentacles of rose limpets are their primary sensory organs, although all of the soft tissue is sensitive to pressure. The tentacles are highly sensitive chemoreceptors, they are finely tuned to detect the chemicals released by decaying flesh. The tentacles are also extremely sensitive to touch, and the timing delay of them sensing pressure waves in the water can alert the rose limpet to not just the presence of a larger organism moving near it, but also to its direction. The last form of sensory information the tentacles provide is extremely simple photoreceptivity. This allows the organism to know roughly what time of day it is, and also if there is a sudden change of light it may indicate a predator, provoking a defensive response.
EXTINCT
Genetic Ancestor(s)
Scientific Name
Testaharanae planus
Origin/Ancestry
Stephanozoa
Lifespan
3-5 local years
Average Height
0.5 cm
Average Length
2.5 cm
Body Tint, Colouring and Marking
The tint of the shell will vary based on the mineral composition of the local water. While the shell is composed of silicates, trace impurities will make their way in, and change to color.
Geographic Distribution
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