Territorial prior residence, size asymmetry, and escalation of aggression in convict cichlids (Cichlasoma nigrofasciatum Günther)

Abstract

The present study was designed to assess the effects of resident versus intruder size differences upon the territorial prior‐residence effect and level of territorial aggression in convict cichlids. Prior to a direct territorial dominance encounter, pairs of fish were randomly composed for one of three experimental treatment conditions: 1) the resident having a body‐length 20–30% larger than that of the intruder, 2) the intruder having a body‐length 20–30% larger than the resident, or 3) the combatants' body‐lengths differing by no more than 5%. After a 3‐day territorial acclimation period in their individual territories, the subject designated as the intruder was introduced to the resident's territory. For each encounter the pairmember that attacked first and the one that ultimately established dominance were recorded. Also measured during the encounter were the total number of bites, resident bites, intruder bites, and jaw‐locking frequency and duration. The results revealed that there was a significant resident advantage in the resident‐larger group. The intruder‐larger group resulted in a significant intruder dominance advantage. However, no significant dominance advantage occurred in the same‐size group. As predicted by game theory, there was significantly less escalation of aggression in contests in which one combatant held both designated asymmetric cues (prior residence, size) than in contests in which one combatant had prior residence, or when these two asymmetric cues were divided between the pairmembers. The size asymmetry is more important in determining dominance than the prior‐residence asymmetry, for the particular size‐difference range selected in the present study.

Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

“…In addition to prior residence, there are other important variables. Size is important in determining the outcome of contests in cichlids (Barlow et al 1986;Wazlavek and Figler 1989;Keeley and Grant 1993;Turner 1994). Temperature would also be a potential factor, especially with the tropical cichlids (Ratnasabapathi et al 1992).…”

Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

“…In addition to prior residence, there are other important variables. Size is important in determining the outcome of contests in cichlids (Barlow et al 1986;Wazlavek and Figler 1989;Keeley and Grant 1993;Turner 1994). Temperature would also be a potential factor, especially with the tropical cichlids (Ratnasabapathi et al 1992).…”

Maternal territoriality as an offspring defense strategy in red swamp crayfish (Procambarus clarkii, Girard)

“…However, the males initiated aggression in a significantly higher proportion of the bouts than did nonmaternal female residents. Initiation of aggression is a common feature of territorial residents, in general [see Figler et al, 1995b;Wazlavek and Figler, 1989]. Also, initiation of aggression was reliably related to winning a bout, a common finding in our past studies, as well as in other crustacean research [Figler et al, 1995b].…”

Behavioral response to familiar and unfamiliar neighbors in a territorial cichlid, Neolamprologus pulcher

“…In an area where all suitable habitat is being defended by territorial individuals, an unfamiliar intruder will pose more of a potential threat to a resident than a familiar neighbor because the intruder may be searching for a location to establish a territory (Waage, 1988). Such an intruder may become emboldened and try to take over part or all of a resident's territory if the resident does not rapidly and aggressively expel the intruder (Wazlavek and Figler, 1989;Stamps and Krishnan, 1994). Such an aggressive response to a neighbor that shared an established territorial boundary would result in an unnecessary expenditure of energy and an increased risk of injury, and could raise the individual's risk of predation due to the increased conspicuousness and decreased vigilance of fighting fish (Jakobsson et al, 1995;Martel, 1996;Brick, 1998).…”

Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

“…In addition to prior residence, there are other important variables. Size is important in determining the outcome of contests in cichlids (Barlow et al 1986;Wazlavek and Figler 1989;Keeley and Grant 1993;Turner 1994). Temperature would also be a potential factor, especially with the tropical cichlids (Ratnasabapathi et al 1992).…”

Maternal territoriality as an offspring defense strategy in red swamp crayfish (Procambarus clarkii, Girard)

“…However, the males initiated aggression in a significantly higher proportion of the bouts than did nonmaternal female residents. Initiation of aggression is a common feature of territorial residents, in general [see Figler et al, 1995b;Wazlavek and Figler, 1989]. Also, initiation of aggression was reliably related to winning a bout, a common finding in our past studies, as well as in other crustacean research [Figler et al, 1995b].…”

Behavioral response to familiar and unfamiliar neighbors in a territorial cichlid, Neolamprologus pulcher

“…In an area where all suitable habitat is being defended by territorial individuals, an unfamiliar intruder will pose more of a potential threat to a resident than a familiar neighbor because the intruder may be searching for a location to establish a territory (Waage, 1988). Such an intruder may become emboldened and try to take over part or all of a resident's territory if the resident does not rapidly and aggressively expel the intruder (Wazlavek and Figler, 1989;Stamps and Krishnan, 1994). Such an aggressive response to a neighbor that shared an established territorial boundary would result in an unnecessary expenditure of energy and an increased risk of injury, and could raise the individual's risk of predation due to the increased conspicuousness and decreased vigilance of fighting fish (Jakobsson et al, 1995;Martel, 1996;Brick, 1998).…”

Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

“…In addition to prior residence, there are other important variables. Size is important in determining the outcome of contests in cichlids (Barlow et al 1986;Wazlavek and Figler 1989;Keeley and Grant 1993;Turner 1994). Temperature would also be a potential factor, especially with the tropical cichlids (Ratnasabapathi et al 1992).…”

Maternal territoriality as an offspring defense strategy in red swamp crayfish (Procambarus clarkii, Girard)

“…However, the males initiated aggression in a significantly higher proportion of the bouts than did nonmaternal female residents. Initiation of aggression is a common feature of territorial residents, in general [see Figler et al, 1995b;Wazlavek and Figler, 1989]. Also, initiation of aggression was reliably related to winning a bout, a common finding in our past studies, as well as in other crustacean research [Figler et al, 1995b].…”

Behavioral response to familiar and unfamiliar neighbors in a territorial cichlid, Neolamprologus pulcher

“…In an area where all suitable habitat is being defended by territorial individuals, an unfamiliar intruder will pose more of a potential threat to a resident than a familiar neighbor because the intruder may be searching for a location to establish a territory (Waage, 1988). Such an intruder may become emboldened and try to take over part or all of a resident's territory if the resident does not rapidly and aggressively expel the intruder (Wazlavek and Figler, 1989;Stamps and Krishnan, 1994). Such an aggressive response to a neighbor that shared an established territorial boundary would result in an unnecessary expenditure of energy and an increased risk of injury, and could raise the individual's risk of predation due to the increased conspicuousness and decreased vigilance of fighting fish (Jakobsson et al, 1995;Martel, 1996;Brick, 1998).…”