Diurnal activity patterns in two sabellid fan worm species
(2024) BIOM02 20221Degree Projects in Biology
- Abstract
- Many animals have biological and circadian rhythms with periods of more and less activity. Fan worms (Polychaeta: Sabellidae) possess radiolar crowns used for feeding and respiration. These crowns can be retracted into the tube in which the animal lives, or displayed in the water, indicating inactivity or activity. Here, activity patterns based on crown status were studied in the fan worm species Acromegalomma vesiculosum and genus Sabellastarte spp. A. vesiculosum spent more time outside the tubes at nighttime, but lacked any clear or repeated circadian rhythm. Sabellastarte spp. seemed to not show any coherent activity patterns or differences during night or day. There was however a decline in activity in half of the group after a 7 hour... (More)
- Many animals have biological and circadian rhythms with periods of more and less activity. Fan worms (Polychaeta: Sabellidae) possess radiolar crowns used for feeding and respiration. These crowns can be retracted into the tube in which the animal lives, or displayed in the water, indicating inactivity or activity. Here, activity patterns based on crown status were studied in the fan worm species Acromegalomma vesiculosum and genus Sabellastarte spp. A. vesiculosum spent more time outside the tubes at nighttime, but lacked any clear or repeated circadian rhythm. Sabellastarte spp. seemed to not show any coherent activity patterns or differences during night or day. There was however a decline in activity in half of the group after a 7 hour time shift in the simulation of day and night. A. vesiculosum spent most of the time inside the tube and Sabellastarte spp. spent most of the time outside the tube. Outside of A. vesiculosum possibly being night active, this study could not pinpoint driving factors for activity patterns in the fan worms. Results may also have been affected by suboptimal health conditions in the animals and further studies are needed to confirm the findings of this study as well as to expand on questions about activity patterns in fan worms. (Less)
- Popular Abstract
- The mystery of the daily life of fan worms
Circadian rhythms exist in most animals and are important to help us take appropriate actions depending on the time of the day. We are all familiar with day active species such as humans, and night active species such as owls. But are there other types of activity rhythms out there, and what about the animals we are not as familiar with?
Burrowed in the sediment in shallow bottoms of the ocean or nested in cracks of tropical corals live two fan worm groups: species Acromegalomma vesiculosum (left picture) and genus Sabellastarte spp. (right picture). These animals are filter feeders: they rely on a structure on top of the head, known as a crown, to collect food particles from the water as... (More) - The mystery of the daily life of fan worms
Circadian rhythms exist in most animals and are important to help us take appropriate actions depending on the time of the day. We are all familiar with day active species such as humans, and night active species such as owls. But are there other types of activity rhythms out there, and what about the animals we are not as familiar with?
Burrowed in the sediment in shallow bottoms of the ocean or nested in cracks of tropical corals live two fan worm groups: species Acromegalomma vesiculosum (left picture) and genus Sabellastarte spp. (right picture). These animals are filter feeders: they rely on a structure on top of the head, known as a crown, to collect food particles from the water as well as for respiration. This crown can also be retracted as a response to danger.
In this study I observed the worms during the course of the day to see when they were active with the crown displayed or inactive with a retracted crown. A. vesiculosum were slightly more active at night. No individual however kept the same time for their active episodes day after day, as they could have done in a more distinct periodicity.
The activity of Sabellastarte spp. did not have any coherency, these worms rather seemed to be active at random. For Sabellastarte spp. a feature was also added consisting of a disruption in the experimental day/night cycle. This possibly disturbed half of the group so much that they started to hide more regardless of time of the day. It is however also possible that the worms were unhealthy from the beginning, and that a further decline in health just coincided with this disruption.
This leads us to a warning sign when interpreting the results: for unknown reasons the worms used in this study were abnormally unhealthy. Generally during the day, A. vesiculosum spent most of their time in hiding, a feature that may have been caused by their poor health. Sabellastarte spp. had a reversed pattern of spending most of their time with the crown displayed. They, as the aforementioned group, did however decline in health during the course of this study and any conclusions need to be viewed cautiously.
Then what does this tell us about the daily activity patterns of these fan worms? A. vesiclusom might be night active, and Sabellastarte spp. seem to not have any circadian rhythm at all. Further studies using healthier worms are of importance to confirm findings here, and intriguing questions remain. What are the driving forces of any circadian rhythms in these fan worms? How does rest and activity manifest in the physiology and behavior of the worm? Do they sleep like we do, do they rest but in short episodes of time, or do they have completely different and unknown mechanisms of activity and inactivity? Hopefully future studies will dive deeper into these questions as we begin to explore the lives and days of the more unknown animals of the oceans.
Master’s Degree Project in Biology, 30 credits, 2024
Department of Biology, Lund University
Advisor: Michael Bok
Lund Vision Group, Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9154808
- author
- Romson, Julia
- supervisor
-
- Michael Bok LU
- organization
- course
- BIOM02 20221
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9154808
- date added to LUP
- 2024-05-28 11:45:57
- date last changed
- 2024-05-28 11:45:57
@misc{9154808,
abstract = {{Many animals have biological and circadian rhythms with periods of more and less activity. Fan worms (Polychaeta: Sabellidae) possess radiolar crowns used for feeding and respiration. These crowns can be retracted into the tube in which the animal lives, or displayed in the water, indicating inactivity or activity. Here, activity patterns based on crown status were studied in the fan worm species Acromegalomma vesiculosum and genus Sabellastarte spp. A. vesiculosum spent more time outside the tubes at nighttime, but lacked any clear or repeated circadian rhythm. Sabellastarte spp. seemed to not show any coherent activity patterns or differences during night or day. There was however a decline in activity in half of the group after a 7 hour time shift in the simulation of day and night. A. vesiculosum spent most of the time inside the tube and Sabellastarte spp. spent most of the time outside the tube. Outside of A. vesiculosum possibly being night active, this study could not pinpoint driving factors for activity patterns in the fan worms. Results may also have been affected by suboptimal health conditions in the animals and further studies are needed to confirm the findings of this study as well as to expand on questions about activity patterns in fan worms.}},
author = {{Romson, Julia}},
language = {{eng}},
note = {{Student Paper}},
title = {{Diurnal activity patterns in two sabellid fan worm species}},
year = {{2024}},
}