A Comparative Study on Two Territorial Fishes: The Influence of Physical Enrichment on Aggressive Behavior
Intraspecific aggression is detrimental to body/fin damage, physiological stress, and other problems in aquaculture. Environmental enrichment has been proposed to have positive effects on fish aggressive behavior, physiological stress, and fish welfare, but there are mixed results. Here, we examine the impact of physical enrichment levels (i.e., the intensity of physical enrichment) on aggression in […]
Preference and Motivation Tests for Body Tactile Stimulation in Fish
We tested whether territorial fish (Nile tilapia) perceive body tactile stimulation as a positive or negative resource. Individual male fish were placed for eight days in an aquarium containing a rectangular PVC frame, which was filled with vertical plastic sticks sided with silicone bristles in the middle of the tank. Fish passing this device received […]
Environmental enrichment techniques and tryptophan supplementation used to improve the quality of life and animal welfare of Nile tilapia
The adoption of high standards of animal welfare improves the quality of life for animals being reared and produces improved end products for consumers. In this study, we investigate the role of environmental enrichment and tryptophan supplementation in increasing animal welfare indices in tilapia. To do this, the environment where fish are reared is enriched […]
Injections to pregnant mice produce prenatal stress that affects aggressive behavior in their adult male offspring
Maternal stress could reprogram the developing fetal nervous system. A common target of maternal glucocorticoids is fetal neuro-endocrine axis. In the present study, pregnant mice were exposed to stress by injection and their male offspring were tested for sexual and aggressive behaviors in adult life. Three groups of pregnant mice were exposed to stress by […]
Aggressive behaviour traits predict physiological stress responses in Nile tilapia (Oreochromis niloticus)
This study tested whether aggressive behaviour can predict individual variation in stress responses of Nile tilapia Oreochromis niloticus.We used a mirror test to measure tendency to aggressive behaviour, and calculated the attack frequency and time until the first attack (latency) for each fish. One day later, we measured plasma cortisol and glucose, and two days […]
Social experience in early ontogeny has lasting effects on social skills in cooperatively breeding cichlids
The early social environment can affect the social behaviour of animals throughout life. We tested whether the presence of adults during early development influences the social behaviour of juveniles later on in the cooperatively breeding cichlid Neolamprologus pulcher. In a split-brood design we raised half of the broods together with parents and with or without […]
Differential resource use, growth, and the ontogeny of social relationships in the green iguana
Growth rates, resource use, and ontogeny of behavior patterns were examined in captive groups of juvenile green iguanas (Iguana iguana). Four groups were housed in large arenas where supplemental heat and perch sites were limited, whereas two control groups were housed in similar arenas without limited resources. Growth, frequency and types of displays, behavioral interactions, […]
Is corticosterone involved in the reproductive processes of the male lizard, Podarcis sicula sicula?
Corticosterone (B) and testosterone (T) plasma levels and the effects of short (1-48 min) and long (6-192 hr) confinement stress during the various phases of the reproductive period of the male lizard, Podarcis sicula sicula, were studied; in addition, the in vitro effects of B on the T secretion by testis and adrenals were evaluated. […]
Companion Dog Temperament Traits
Owners rated their companion dogs (Canis faamiliarus) on the frequency of occurrence of 127 descriptions of behavior. We conducted an exploratory principal components analysis of these behaviors for 2,018 participants that produced 22 interpretable factors (or traits). Four related to aggression indicate that aggression is not a unitary concept. Three factors relate to play and […]
Dominance hierarchies and social status ascent opportunity: Anticipatory behavioral and physiological adjustments in a Neotropical cichlid fish
In this work we characterized the social hierarchy of non-reproductive individuals of Cichlasoma dimerus (Heckel, 1840), independently for both sexes, and its relationship to the opportunity for social status ascent. Female and male individuals who were located on the top rank of the social hierarchy, ascended in social status when the opportunity arose, therefore indicating […]