Responses of crayfish to a reflective environment depend on dominance status

2006 ◽  
Vol 84 (8) ◽  
pp. 1104-1111 ◽  
Author(s):  
H.Y. May ◽  
A.J. Mercier
Keyword(s):  
Dominance Hierarchy ◽  
Procambarus Clarkii ◽  
The Other ◽  
Dominance Status ◽  
Behavioural Responses

Previous work has shown that the reflection from aquarium walls can modify several aspects of crayfish behaviour, but only if the crayfish are socialized. Such socialization is known to generate a dominance hierarchy composed of dominant and subordinate animals. The present study was conducted to determine whether or not behavioural responses to reflection depend on dominance status. Procambarus clarkii (Girard, 1852) were maintained in pairs for 2 weeks to establish dominance ranks and were subsequently observed in an aquarium in which half of the walls were lined with mirrors and the other half were lined with nonreflective plastic. Dominant crayfish spent more time on the reflective side of the aquarium than on the nonreflective side, and they spent more time in reflective corners than in nonreflective corners. Dominant crayfish also turned more frequently on the reflective side and crossed the tank more frequently toward reflective walls. Such differences in behaviour were not observed for subordinate crayfish or for crayfish that had been isolated for 2 weeks. Subordinate crayfish exhibited more reverse walking on the reflective side of the aquarium than on the nonreflective side, but crayfish in the other groups did not. Thus, responses of crayfish to reflection depend on dominance status.

Lanthanum penetration in crayfish nervous system: observations on intact and ‘desheathed’ preparations

1977 ◽  
Vol 23 (1) ◽  
pp. 315-324
Author(s):  
N.J. Lane ◽  
L.S. Swales ◽  
N.J. Abbott
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Peripheral Nerves ◽  
Procambarus Clarkii ◽  
Physiological Saline ◽  
The Other ◽  
Major Site ◽  
Electrophysiological Studies ◽  
Cell Processes ◽  
Tubular Lattice

Central neural connectives and peripheral nerves from the crayfish Procambarus clarkii were incubated in 5 mM lanthanum solutions in physiological saline, for periods from 15 min to 2 h. The tracer only rarely reaches the axon surfaces in the perineurium-ensheathed connectives, penetrating the elaborate perineurial layer slowly. In peripheral nerves, on the other hand, where the perineurium is extermely attenuated and interrupted by open extracellular clefts, inward movement of lanthanum to the axon surfaces occurs readily. When the perineurial layer of the neural connectives is removed by ‘desheathing’, penetration of the tracer to the level of the axolemma occurs rapidly, implicating the perineurium as the major site of restriction of entry of large ions and exogenous molecules. This conclusion is discussed in relation to recent electrophysiological studies on K+ movements. In both peripheral nerves and desheathed connectives, the transcellular tubular lattice system present in crustacean glial cells appears to serve as a route for the entry of tracer to the axon surfaces, and is more direct than the long and complex extracellular pathway formed by the interdigitations of the extensive glial cell processes.

Do Male Black-capped Chickadees Eavesdrop on Song Contests? A Multi-speaker Playback Experiment

Behaviour ◽  
2004 ◽  
Vol 141 (1) ◽  
pp. 125-139 ◽  
Author(s):  
Laurene Ratcliffe ◽  
Daniel Mennill
Keyword(s):  
Equilateral Triangle ◽  
Low Cost ◽  
The Other ◽  
Territorial Male ◽  
Territorial Defense ◽  
Dominance Status ◽  
Poecile Atricapillus ◽  
The Subject ◽  
Relative Quality

AbstractWithin a network of communicating individuals, animals may gather information about the relative quality of conspecifics by eavesdropping on their signalling interactions. For territorial male songbirds, eavesdropping may be a low-cost, low-risk method for assessing the relative quality of the males around them. We used a three-speaker playback design to evaluate whether male black-capped chickadees (Poecile atricapillus) respond differently to two simulated countersinging intruders who differ only in relative features of their singing performance. We arranged three loudspeakers in an equilateral triangle at the center of playback subjects' territories. After luring males to the first loudspeaker by broadcasting non-song vocalizations, we played songs from the remaining loudspeakers to simulate a countersinging interaction between two male intruders. During the interactions, one simulated intruder consistently overlapped the songs of the other, a behaviour thought to be a signal of directed aggression in songbirds. Territorial male chickadees discriminated between the simulated intruders by preferentially approaching the loudspeaker broadcasting the overlapping signal, suggesting that males eavesdrop on other males' countersinging interactions. Male responses to playback support the idea that overlapping is a more threatening signal than being overlapped. Responses varied with the dominance status of the subject. High-ranking males approached the overlapping loudspeaker in 15 of 16 cases whereas low-ranking males approached the overlapping speaker in only 5 of 10 cases, suggesting that males of different quality may use different tactics for territorial defense.

The Evolution of Mating Systems in Temperate Zone Dragonflies (Odonata: Anisoptera) Ii: Libellula Luctuosa (Burmeister)

Behaviour ◽  
1975 ◽  
Vol 54 (3-4) ◽  
pp. 278-310 ◽  
Author(s):  
Paul J. Campanella
Keyword(s):  
New York ◽  
Behavioral Ecology ◽  
Mating Systems ◽  
Dominance Hierarchy ◽  
New York State ◽  
Time Of Day ◽  
Relative Advantage ◽  
Dominant Male ◽  
Dominance Status ◽  
Number Of Males

AbstractThe behavioral ecology of Libellula luctuosa (Burmeister) (Odonata: Anisoptera) was studied at several ponds in northern New York State, U.S.A. The male Libellula maintained territories which were slightly overlapping on each pond. As many as six males utilized each territorial sector of the pond concurrently. Conspecifics showing submissive behavior were allowed on the mating site, and all males on the territory recognized and maintained the boundaries. These communal sites were primarily mating/ovipositing areas. Aggressive interactions among co-occurring males resulted in the establishment of a dominance hierarchy on each territory. The dominance hierarchy increased the reproductive efficiency of the dominant male probably by reducing interference with mating. Subordinate males occasionally mated. The relative advantage of dominance in mating attempts is quantified. The average number of males at the pond changed little during the day and males did not localize their behavior to specific parts of the pond. An individual male returned to the pond an average of 5 different days. While at the water, males either flew over a territory or perched adjacent to the pond. Individuals frequently left the pond and returned during the day. The amount of time spent in each activity depended on the time of day and number of conspecific competitors. Site attachment was low and males commonly flew to different territorial sectors. The dominance status of individual males often changed quite rapidly, especially when changing sectors or upon returning to the pond. Female Libellula occurred at low average daily density and showed no preference for specific areas of the pond or for certain times of day. Time budgets and analyses of mating behavior of Libellula luctuosa are considered with regard to the males' response to the availability and predictability of females and mating/ ovipositing sites. The behavioral patterns are analyzed with reference to a time-energymaturational-experiential hypothesis for the evolution of the behavior. Extensive comparisons are made between Libellula luctuosa (Burmeister) and Plathemis lydia (Drury).

scholarly journals Regional Phenotypic Differences of the Opener Muscle in Procambarus clarkii: Sarcomere Length, Fiber Diameter, and Force Development

Biology ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 118 ◽  
Author(s):  
Rachel C. Holsinger ◽  
Robin L. Cooper
Keyword(s):  
Sarcomere Length ◽  
Procambarus Clarkii ◽  
Fiber Diameter ◽  
Troponin T ◽  
Input Resistance ◽  
The Other ◽  
Phenotypic Differences ◽  
Synaptic Structure ◽  
Frequency Of Stimulation ◽  
40 Hz

The opener muscle in the walking legs of the crayfish (Procambarus clarkii) has three distinct phenotypic regions although innervated by only one excitatory motor neuron. These regions (distal, central, and proximal) have varied biochemistry and physiology, including synaptic structure, troponin-T levels, fiber diameter, input resistance, sarcomere length, and force generation. The force generated by the central fibers when the excitatory neuron was stimulated at 40 Hz was more than the force generated by the other regions. This increase in force was correlated with the central fibers having longer sarcomeres when measured in a relaxed claw. These data support the idea that the central fibers are tonic-like and that the proximal fibers are phasic-like. The addition of serotonin directly on the fibers was hypothesized to increase the force generated by the central fibers more than in the other regions, but this did not occur at 40-Hz stimulation. We hypothesized that the central distal fibers would generate the most force due to the arrangement on the apodeme. This study demonstrates how malleable the motor unit is with modulation and frequency of stimulation.

Individual and group behaviour of pastured cattle in response to attack by biting flies

1993 ◽  
Vol 71 (4) ◽  
pp. 725-734 ◽  
Author(s):  
Wendy E. Ralley ◽  
Terry D. Galloway ◽  
Gary H. Crow
Keyword(s):  
Canonical Discriminant Analysis ◽  
The Other ◽  
Whole Body ◽  
Behavioural Responses ◽  
Group Behaviour ◽  
Before And After ◽  
Horse Flies ◽  
The Impact ◽  
Biting Fly ◽  
Behaviour Data

In 1983 and 1984 the impact of biting flies on the behaviour of pastured heifers was determined for two herds of cattle in eastern Manitoba. One herd received a whole-body spray of cypermethrin (0.1% active ingredient) per animal every 14 days and the other was an untreated control herd. Horse flies (predominantly Hybomitra spp.) were the most bothersome to the heifers, with peak numbers of flies mostly occurring between 11:00 and 15:00. Horse flies and mosquitoes (Aedes spp.) caused an increase in individual avoidance responses of the animals, including head tosses, foot stomps, ear flicks, and tail switches. In 1983, the numbers of tail switches and foot stomps were significantly higher in the control herd, and in 1984, the numbers of head tosses were significantly higher in the treated herd. The formation of grazing lines and bunching were the most prevalent herd responses to biting fly attack. Stampeding was observed only under the most extreme mosquito pressure. Using canonical discriminant analysis on behaviour data, significant differences were identified in behaviour before and after July 10, 1984. Similarly, animals treated with cypermethrin displayed significantly fewer behavioural responses to biting fly attack than nontreated animals.

Behavioural Physiology of the Colonial Hydroid Obelia

1971 ◽  
Vol 54 (3) ◽  
pp. 689-706
Author(s):  
JAMES G. MORIN ◽  
IAN M. COOKE
Keyword(s):  
Mouth Opening ◽  
The Other ◽  
Behavioural Responses ◽  
Electrical Potentials ◽  
External Stimuli ◽  
Colonial Hydroid ◽  
Obelia Geniculata

1. Spontaneous electrical potentials from Obelia geniculata hydranths were recorded using fine-tipped suction electrodes. 2.The primary behavioural responses of the hydranths were observed and correlated with specific electrical potentials: the contraction potential (KP) associated with hydranth withdrawal, the mouth-opening potential (MOP) associated with mouth opening, and the tentacle contraction potential (TKP) associated with oral flexion of individual tentacles. 3. KPs occurred in rhythmic bursts while the TKP and MOP responses were infrequent and non-rhythmic. 4. Two other species, O. longissima and Gonothyraea loveni, were shown to produce the same three types of potentials with corresponding behavioural responses. 5. The MOP activity may occasionally drive the KP responses within a hydranth, but the coupling is very loose. None of the other possible interactions within a hydranth was observed. 6. No interaction of any of the potentials between adjacent hydranths was found in the absence of external stimuli. 7. It seems likely that the KPs in Obelia are homologous with the contraction potential (CP) in Hydra and the hydranth potential (HP)) in Tubularia. MOP and TKP activity do not show apparent homologies with potentials of the other hydroids Hydra, Tubularia and Cordylophora.

Interspecific competition between two generalist parasitoids that attack the leafrollerEpiphyas postvittana(Lepidoptera: Tortricidae)

2015 ◽  
Vol 105 (4) ◽  
pp. 426-433 ◽  
Author(s):  
Y. Feng ◽  
S. Wratten ◽  
H. Sandhu ◽  
M. Keller
Keyword(s):  
Larval Development ◽  
Interspecific Competition ◽  
The Other ◽  
Native Vegetation ◽  
Epiphyas Postvittana ◽  
Host Discrimination ◽  
Natural Habitats ◽  
Behavioural Responses ◽  
Interspecific Differences ◽  
Light Brown Apple Moth

AbstractTwo generalist parasitoids,Dolichogenidea tasmanica(Cameron) (Hymenoptera: Braconidae) andTherophilus unimaculatus(Turner) (Hymenoptera: Braconidae) attack early instars of tortricid moths, including the light brown apple moth,Epiphyas postvittana(Walker) (Lepidoptera: Tortricidae). The two parasitoids co-exist in natural habitats, whileD. tasmanicais dominant in vineyards, whereasT. unimaculatusoccurs mainly in adjacent native vegetation. This difference suggests possible competition between the two species, mediated by habitat. Here, we report on the extent of interspecific differences in host discrimination and the outcome of interspecific competition between the two parasitoids. The parasitoids did not show different behavioural responses to un-parasitized hosts or those that were parasitized by the other species. Larvae ofD. tasmanicaout-competed those ofT. unimaculatus, irrespective of the order or interval between attacks by the two species. The host larvae that were attacked by two parasitoids died more frequently before a parasitoid completed its larval development than those that were attacked by a single parasitoid. Dissection of host larvae parasitized by both species indicated that first instars ofD. tasmanicaattacked and killed larvalT. unimaculatus.

The Behavior of the Male Antilope Cervicapra L., Its Development According To Age and Social Rank

Behaviour ◽  
1981 ◽  
Vol 76 (1-2) ◽  
pp. 62-125 ◽  
Author(s):  
François Feer ◽  
Gérard Dubost
Keyword(s):  
Individual Differences ◽  
Dominance Hierarchy ◽  
Qualitative Difference ◽  
The Other ◽  
Physical Contact ◽  
Large Individual ◽  
Courtship Display ◽  
High Ranking ◽  
In The Wild ◽  
Antilope Cervicapra

AbstractA population of Antilope cervicapra L. was studied from 1971 to 1976 in the park of Clères, north of Rouen (France). The animals range freely over an area of more than 6 ha, which seems similar to the habitat used by the species in the wild. The social behaviors of the ♂ ♂ blackbuck have been recorded and counted, according to the herd in which each animal lives, and his hierarchical rank. The population splits into a number of social units. Females and young are grouped into a herd that occupies the best grasslands. The strongest ♂ establishes a territory in this area, which he defends against other ♂ ♂ . The other adult or young ♂ ♂ form a bachelor herd that lives on a large grassland on the opposite end of the park. Certain times of day the highest ranking ♂ ♂ in the dominance hierarchy leave the bachelor herd and defend territories adjacent to the harem. The 9 9 sometimes pass through these territories. From time to time the hierarchy changes, and certain ♂ ♂ replace the territorial ♂ ♂ , which in turn rejoin the bachelor herd. Adjacent ♂ ♂ territories divide the 9 ♀ home range. Many threats and parallel displays take place on the borders between neighboring territories. The territorial limits are determined only by the ♂ with the smallest territory, regardless of the identity or strength of his neighbor. The number of territories grows regularly with the size of the harem. The blackbuck ♂ shows 6 different marking behaviors that mature as the animal grows. There is generally no qualitative difference in marking behavior between ♂ ♂ ; however the territorial ♂ performs a more complete urination-defecation sequence than the others and he only emits the barking. All ♂♂ have similar "Flehmen" display, but the α- ♂ shows it more often than other ♂ ♂, as do adults compared to young ♂ ♂ ; the urine of 9 9 releases "Flehmen" more often than that of ♂ ♂ . The courtship display is complex and requires maturation. Yearlings and two-year-old ♂ ♂ perform it indistinctly and direct it incompletely towards any conspecific. Adult ♂ ♂ perform the complete courtship display towards 9 9 , but there is much homosexual mounting. The α- ♂ directs sexual behaviors only towards 9 ♀. In A. cervicapra society, young ♂♂ with 9 -like appearance are often treated by adult ♂♂ as if they were 9 9 . The main type of play is play-sparring. There are 8 agonistic behaviors. In general these are directed towards animals of lower rank. The dominance display is a social agonistic display that develops progressively with age and is only complete in adults. It has the same form when directed towards either ♂ ♂ or 9 ♀. The main characteristic of the behavior of the blackbuck is the avoidance of physical contacts and the preponderance of visual gestures. There is no visible dominance hierarchy among harem 9 ♀ . The strongest ♂ lives with the 9 9 . All the other ♂ ♂ belonging to the bachelor troup are ordered in a linear hierarchy with occasional equal or triangular relationship. Sick or wounded ♂ ♂ may be temporarily outside of the hierarchy. The youngest ♂ ♂ are at the bottom of the hierarchy and only compete with adults at about 3 years of age, when they may also become territorial or harem ♂♂. The α- ♂ is not replaced by the strongest bachelor, but by a ♂ of middle rank. The β- ♂ never becomes α-♂, nor vice versa. Among bachelors there are two independent hierarchies: one leading to α status, and one to β, with no passage from one to the other. Individual ♂ ♂ belong to either one or the other category. Most harem ♂ ♂ are younger than other territorial ♂ ♂ . There is no difference in marking behavior between bachelors, but territorial ♂ ♂ are distinguished by more types of behavior, given more completely and more frequently. There are large individual differences in tendency to play, which is inversely related to the rank in the hierarchy: the α-♂ never plays. Each ♂ has 4 to 6 partners for play. Choice of partners depends directly on rank: high ranking ♂ ♂ (2-5) only play with much lower ranking individuals, thus exluding those in close competition in the hierarchy. Those in the lower half of the herd (6-11), in contrast, are unconstrained and play with partners of any rank. The agonistic behaviors are more often directed towards animals of lower but close rank. Among hornless or small-horned individuals ( 9 9 and young ♂ ♂) there are many encounters involving butting and sparring, but among older ♂ ♂ the more violent engagements involving physical contact are rare. There are large individual differences in agonistic behavior. In general the higher the rank, the more aggressive is the ♂. In contrast to play, each animal has aggressive encounters with all the others in the herd. There is non-random choice of partners, however: high ranking ♂♂ (2-6) most often threaten those of neighboring rank, while those at the bottom of the hierarchy (7 + below) most frequently engage with ♂♂ 5 ranks above them. We thus have a parallel system of aggression between the two halves of the hierarchy: ♂ 7 with ♂ 2, ♂ 8 with ♂ 3, etc... The sharp division of this herd into two halves according to partners for combat corresponds precisely with that seen in relation to play behavior. In the park of Clères, Antilope cervicapra shows a behavior and social organization identical to that of several African Bovidae of open spaces which have been studied in the wild.

The responses of growing pigs exposed to cold with varying amounts of straw bedding

2000 ◽  
Vol 80 (4) ◽  
pp. 539-546 ◽  
Author(s):  
S. M. Hayne ◽  
T. Tennessen ◽  
D. M. Anderson
Keyword(s):  
Key Words ◽  
Environmental Conditions ◽  
Effective Means ◽  
Thermal Conditions ◽  
Growing Pigs ◽  
The Other ◽  
Behavioural Responses ◽  
Cold Environments ◽  
Kg Medium ◽  
Lateral Posture

Confinement housing of pigs allows optimal thermal conditions to be maintained thus reducing the thermal demand placed on the pig. Alternatives tend to cost less to construct, use less energy to operate and possibly have higher welfare standards than conventional housing; however, the thermal demand on the pig could be greater. An experiment consisting of two trials was conducted to examine the effect of varying amounts of straw bedding on the performance and behaviour of growing pigs while exposed to cold conditions. Four straw bedding treatments were studied and referred to as Least (20 kg), Medium-low (80 kg), Medium-high (137 kg) and Most (196 kg) straw usage. Results from the analysis of the two trials indicated that pigs with the three greatest amounts of straw gained more weight than pigs with the Least straw (P < 0.05). Pigs with the Least straw huddled with a sternal posture and piled more than pigs in the other three treatments (P < 0.05). Pigs with the two highest amounts of straw adopted a lateral posture while huddling more than pigs with the two lowest amounts of straw (P < 0.05). Pigs with the Most straw were also lying alone with a lateral posture more than pigs with the two lowest amounts of straw, and burrowed more than pigs in the other three treatments (P < 0.05). This study provides information on the adaptability of growing pigs exposed to different environmental conditions. Straw bedding was shown to be an important resource used by pigs to aid in thermoregulation in cold environments. Behavioural responses were also shown to be an effective means of adaptation. Key words: Straw bedding, cold conditions, thermoregulation, pigs, behaviour, performance

The unintended consequence of English votes for English laws

2015 ◽  
Vol 233 ◽  
pp. R37-R44 ◽  
Author(s):  
Angus Armstrong ◽  
Monique Ebell
Keyword(s):  
Monetary Policy ◽  
Fiscal Policy ◽  
Member State ◽  
Unintended Consequence ◽  
The Other ◽  
Behavioural Responses ◽  
Policy Choices ◽  
Dominant Member ◽  
Scottish Government ◽  
The Uk

The Scotland Bill 2015–16 would make the Scottish government one of the most powerful sub-central governments in the OECD in terms of its control over spending and taxation. The UK government has also announced plans to introduce ‘English Votes for English Laws’ (EVEL), where the support of a majority of English MPs would be necessary to pass legislation deemed to impact on England only. The objective of this paper is to examine the potential for spillovers to arise in monetary unions of asymmetric nations where fiscal policy choices are taken locally. We extend a model of Chari and Kehoe (2008) to show the sub-optimal consequences of devolved fiscal policy in a moneteary union with a dominant member state. Because England is so much larger than the other constituent nations of the UK, its fiscal policy choices will have a commensurately stronger impact on UK monetary policy. As a result, UK monetary policy might be inappropriate for the smaller nations, calling into question the economic efficiency of EVEL. This is a general result which arises from the asymmetry of nations rather than specific UK funding arrangements or behavioural responses.

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