The Effect of Locomotion and Cold Induced Anaesthesia on Directional Memories of Ball-rolling Dung Beetles
(2022) BION03 20211Degree Projects in Biology
- Abstract
- To roll its dung-ball along straight paths across the African Savanna, the ball-rolling dung-beetle Kheper lamarcki (Mac Leay, 1821) utilizes a broad repertoire of celestial compass cues. These include the position of the sun and the polarization pattern that forms around it. It is hypothesized that a celestial snapshot of these cues needs to be stored in order to support orientation. However, it is not known if the ball-rolling beetles form and maintain directional memories. Here, I investigate the possible presence and nature of the beetle directional memory, focusing on its duration and the factors that affect it. I find that ball-rolling beetles do indeed form some form of directional memories and that they last up to two hours. The... (More)
- To roll its dung-ball along straight paths across the African Savanna, the ball-rolling dung-beetle Kheper lamarcki (Mac Leay, 1821) utilizes a broad repertoire of celestial compass cues. These include the position of the sun and the polarization pattern that forms around it. It is hypothesized that a celestial snapshot of these cues needs to be stored in order to support orientation. However, it is not known if the ball-rolling beetles form and maintain directional memories. Here, I investigate the possible presence and nature of the beetle directional memory, focusing on its duration and the factors that affect it. I find that ball-rolling beetles do indeed form some form of directional memories and that they last up to two hours. The strength of the memory is affected by the presence or absence of the dung ball and locomotory movements. Cold induced anaesthesia resulted in what appeared to be a complete loss of directional memory, i.e., the beetles could no longer orient in the same direction as before this treatment. By describing the general layout and structure of the neuropils in the head direction pathway of the homing dung beetle Scarabaeus galenus (for which possible encoding mechanisms for directional memories have been suggested) and comparing them to the neuropils in the brain of K. lamarcki, I can further confirm that these two species – despite major differences in navigational performances – share similar neuroarchitectures at the level of detail investigated. (Less)
- Popular Abstract
- The scent of dung on the African Savanna can attract several hundreds of dung beetles. All these beetles want to get a share of this dung to eat. To escape this intense competition at the dung pat, ball-rolling dung beetles quickly shape a piece of dung into a ball and roll it away (backwards) in a straight line before burying it for consumption. However, whether it is a beetle or a human being, moving in a straight line requires an external reference for guidance. Kheper lamarcki (Mac Leay, 1821) uses an extraordinary number of celestial compass cues to roll its prize along a straight path. These include the position of the sun, the polarization pattern that forms around it and even the direction of the wind!
It is speculated that in... (More) - The scent of dung on the African Savanna can attract several hundreds of dung beetles. All these beetles want to get a share of this dung to eat. To escape this intense competition at the dung pat, ball-rolling dung beetles quickly shape a piece of dung into a ball and roll it away (backwards) in a straight line before burying it for consumption. However, whether it is a beetle or a human being, moving in a straight line requires an external reference for guidance. Kheper lamarcki (Mac Leay, 1821) uses an extraordinary number of celestial compass cues to roll its prize along a straight path. These include the position of the sun, the polarization pattern that forms around it and even the direction of the wind!
It is speculated that in order to perform this straight-line orientation, the beetle has to store or memorise a snapshot of the available cues for directional information. But, do Kheper lamarcki store such directional information?
In this thesis, I investigated the presence and nature of the beetle direction memory, focusing on its duration and the possible effect of having a dung ball, locomotion and cold induced anaesthesia. Using behavioural experiments in a laboratory setting, I find that ball-rolling beetles do indeed form directional memories. Incredibly, these memories last up to two hours. However, the memory duration is affected by the presence or absence of the dung ball and locomotion during isolation.
How do K. lamarcki store or encode these memories? Cold induced anaesthesia for 30 minutes during isolation (where the body temperature of the beetles was reduced by placing individuals on ice) resulted in a complete loss of directional memory, suggesting that directional memories are stored by a mechanism that can be disturbed by cold induced anaesthesia.
Previous studies (using a similar experimental procedure) suggested that ‘short term synaptic modifications’ may be used for this in the closely related homing dung beetle, Scarabaeus galenus. By describing the general layout and structure of the neuropils in the head direction pathway of the homing dung beetle Scarabaeus galenus and comparing them to the neuropils in the brain of K. lamarcki, I suggest that these two species share similar neuroarchitectures at the level of detail investigated and may thus encode information using similar mechanisms.
Main supervisor: Dr. Ayse Yilmaz-Heusinger
Co-supervisor: Prof. Marie Dacke
Master’s Degree Project in Biology, 60 credits 2022
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/9075430
- author
- Ellendula, Saroja
- supervisor
- organization
- course
- BION03 20211
- year
- 2022
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9075430
- date added to LUP
- 2022-02-16 09:28:10
- date last changed
- 2022-02-16 09:28:10
@misc{9075430,
abstract = {{To roll its dung-ball along straight paths across the African Savanna, the ball-rolling dung-beetle Kheper lamarcki (Mac Leay, 1821) utilizes a broad repertoire of celestial compass cues. These include the position of the sun and the polarization pattern that forms around it. It is hypothesized that a celestial snapshot of these cues needs to be stored in order to support orientation. However, it is not known if the ball-rolling beetles form and maintain directional memories. Here, I investigate the possible presence and nature of the beetle directional memory, focusing on its duration and the factors that affect it. I find that ball-rolling beetles do indeed form some form of directional memories and that they last up to two hours. The strength of the memory is affected by the presence or absence of the dung ball and locomotory movements. Cold induced anaesthesia resulted in what appeared to be a complete loss of directional memory, i.e., the beetles could no longer orient in the same direction as before this treatment. By describing the general layout and structure of the neuropils in the head direction pathway of the homing dung beetle Scarabaeus galenus (for which possible encoding mechanisms for directional memories have been suggested) and comparing them to the neuropils in the brain of K. lamarcki, I can further confirm that these two species – despite major differences in navigational performances – share similar neuroarchitectures at the level of detail investigated.}},
author = {{Ellendula, Saroja}},
language = {{eng}},
note = {{Student Paper}},
title = {{The Effect of Locomotion and Cold Induced Anaesthesia on Directional Memories of Ball-rolling Dung Beetles}},
year = {{2022}},
}