Animal Diversity Anemone Paper Flashcards
Contest theory predicts the evolution of a stable…
mixture of different strategies for fighting
Which sea anemone was studied in this paper?
Beadlet sea anemone, Actinia equina
Both winners and losers showed significant repeatability of…
pre-fight startle-response durations
However, mean pre-fight startle-response durations were greater for eventual … than for eventual …, indicating that RHP (resource-holding potential) varies with …
losers, winners, boldness
RHP stands for…
resource-holding potential
Higher RHP =
higher fighting ability
Individuals with … startle responses inflicted more … on their opponent.
short, attacks
Both repeatability and mean-level responses were changed by the … of fighting, and these changes varied with …. In losers, repeatability was disrupted to a … extent and the mean startle-response durations were subject to a … … than in winners
experience, outcome, greater, greater increase
Victory in a fight is typically determined by …, so that the encounter ends when one individual (the loser) decides to … from the contest and … the resource
persistence, withdraw, relinquish
What are ‘winner and loser’ effects?
When RHP is altered as a result of experiencing a particular fight outcome.
Actinia equina have recently been shown to settle fights using a decision rule based on ‘…-…’, whereby an individual’s … in a contest is based on its own RHP but is … … by information about the RHP of the opponent .
self-assessment, persistence, not influenced
Contests in A. equina occur over ownership of … on … …, and involve the use of organelles called ….
space, intertidal substrates, nematocysts
In A. actinia, nematocysts are present in especially dense concentrations in specialized fighting tentacles called ‘…’.
acrorhagi
In fights that do not involve acrorhagial peels, overall … … appears to be the primary morphological driver of RHP
body size
If peels do occur, then RHP appears to be determined by average … … if only one individual stings its opponent; but if both individuals use the acrorhagi, then it is the ability to … the opponent (assessed by counting the number of … deposited) that appears to determine the chance of victory
nematocyst length, strike, peels
Why are beadlet anemones an ideal study species in which to investigate the role of a potential correlate of absolute RHP?
Because they use self-assessment to settle fights
Why were anemones of the red/brown colour morph from the mid/upper shore in Plymouth used, as opposed to the green/orange morphs and individuals found on the lower shore?
They have been shown to be more aggressive
How was the first startle response invoked?
By rapidly discharging a 50ml syringe filled with sea water into the oral disk from a distance of approximately 2 cm
(the duration of the response was timed from the point at which the stimulus was applied to the point at which the anemone re-opened its tentacles fully)
The fights were considered concluded when one of the contestants either moved away from its opponent by one … … diameter (estimated visually) or … all of its … for 10 mins
pedal disk, retracted, tentacles
There was significant repeatability in startle-response duration for all individuals (winners and losers) combined, but not for …
losers
With losers there was a correlation between startle times for pre-fight 1 and 2, but not for pre-fight 2 and …
post-fight
The mass of winners was…
greater than that of losers
There was … … in mean nematocyst length between fights that did and did not involve peels, … between winners and losers
no difference, nor
However, a paired t-test comparing mean nematocyst length in winners and losers indicated that, overall…
Winners had longer nematocysts than did losers
There was a strong … relationship between the mean duration of the pre-fight startle-response durations and the number of peels inflicted on the opponent
negative
