Effects of Wolf Spiders' Captive Environment on Their Locomotor and Exploratory Behaviours.

Here I detail the effects of the abiotic/captive environment of an adult wandering spider, () on its behaviour. These studies focused on spiders collected as adults in their natural environment and spiders developed in the laboratory under controlled conditions. Wild-caught spiders were tested either immediately after capture or after being housed for 15 days post-collection.

Transport pathways of hydrocarbon and free fatty acids to the cuticle in arthropods and hypothetical models in spiders.

Cuticular lipids in terrestrial arthropods are not only essential for desiccation resistance; they also play an important role as chemical signals for intra- and interspecific communication (pheromones and kairomones, respectively). Most of the studies on cuticular lipid research was dedicated to one class of arthropods, the insects. This type of research on the class arachnids is poorly developed, and the majority of studies has listed the compounds present in cuticular extracts, and, in some cases, compared the lipid profiles of different life stages (juveniles, adults).

Variations of cocoon external lipids during wolf spiderlings' development.

This study presents the first characterisation of the silk lipids of the cocoons of a wolf spider (Pardosa saltans). Wolf spiders' maternal behaviour is complex and involves guarding a cocoon for several weeks, and so cocoons must emit cues to ensure their care and the development of juveniles. We investigated cues associated with the cocoon silk.

Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae).

Wolf spiders' (Lycosidae) maternal behaviour includes a specific phase called "egg brooding" which consists of guarding and carrying an egg-sac throughout the incubation period. The transport of an egg-sac can restrict mothers' exploratory and locomotor activity, in particular when foraging. The present study details the ontogeny of maternal behaviour and assesses the influence of age of egg-sac (or embryos' developmental stage) on vagrant wolf spider Pardosa saltans females' exploration and locomotion.

Physiological costs during the first maternal care in the wolf spider Pardosa saltans (Araneae, Lycosidae).

Many arachnids like other terrestrial arthropods, provide extensive maternal care. Few studies have quantified the underlying physiological costs of maternal care. We investigated how maternal care affects the free-moving wolf spider's (Pardosa saltans) energy requirements.

Mares prefer the voices of highly fertile stallions.

We investigated the possibility that stallion whinnies, known to encode caller size, also encoded information about caller arousal and fertility, and the reactions of mares in relation to type of voice. Voice acoustic features are correlated with arousal and reproduction success, the lower-pitched the stallion's voice, the slower his heart beat and the higher his fertility. Females from three study groups preferred playbacks of low-pitched voices.

Long-life partners or sex friends? Impact of parental pair bond on offspring personality.

Previous investigations reported that some traits of parental relationships, including pair-bond duration or mate behavioural compatibility, influence subsequent offspring fitness by acting on their behaviour and growth and thus their early survival. We hypothesized that the development of a pair bond between sexual partners would have a prenatal influence. This study investigated the impact of two pairing managements on the egg characteristics and development of offspring of Japanese quail (Coturnix c.

It takes a mouth to eat and a nose to breathe: abnormal oral respiration affects neonates' oral competence and systemic adaptation.

Mammalian, including human, neonates are considered to be obligate nose breathers. When constrained to breathe through their mouth in response to obstructed or closed nasal passages, the effects are pervasive and profound, and sometimes last into adulthood. The present paper briefly surveys neonates' and infants' responses to this atypical mobilisation of the mouth for breathing and focuses on comparisons between human newborns and infants and the neonatal rat model.

Juvenile development, ecdysteroids and hemolymph level of metabolites in the spider Brachypelma albopilosum (Theraphosidae).

In the present work, juvenile development and physiological state of mygalomorph Brachypelma albopilosum were investigated by means of individual rearing under controlled conditions. Males required 4-5 years for development from first juvenile instar to adulthood, passing through 8 to 12 juvenile molts. Females developed to adults in 5-6 years with a variable juvenile molt number from 9 to 13.

Craniofacial development and physiological state after early oral breathing in rats.

In this study we determined whether craniofacial development in rats could be influenced by an early temporary (3 d) nasal obstruction associated with forced oral breathing. The rats were killed at specific time points after surgery. Plasma samples were taken for biochemical analyses, and cephalometric measurements were performed.

Effects of short term forced oral breathing: physiological changes and structural adaptation of diaphragm and orofacial muscles in rats.

Objective: We studied adaptation of diaphragm and orofacial muscles as well as hormonal responses to forced oral breathing (lasting for only 4 days) following reversible bilateral nasal obstruction performed on day 8 post-natal male rats.

Design: Muscle myosin heavy chain (MHC) composition and hormone levels were analysed during two periods: 1 and 3 days after obstruction (days 9 and 11 post-natal), and following 3 months recovery with nasal breathing (90 days, adult).

Results: Diaphragm muscle showed significant increases in adult isoforms (MHC 1, 2a) in oral breathing group versus control.

In vitro digestibility of α-casozepine, a benzodiazepine-like peptide from bovine casein, and biological activity of its main proteolytic fragment.

α-Casozepine is a peptide, corresponding to the sequence 91-100 of the bovine α(s1)-casein, displaying anxiolytic activity in the rat. The α(s1)-casein tryptic hydrolysate containing this peptide decreases stress effects after oral administration in various species including man. Therefore, the stability of this peptide toward gastric and pancreatic proteases has been assessed by using pepsin, chymotrypsin/trypsin, Corolase PP, pepsin followed by chymotrypsin/trypsin or pepsin followed by Corolase PP.

Agonistic interactions, cuticular and hemolymphatic lipid variations during the foraging period in spider females Brachypelma albopilosa (Theraphosidae).

Agonistic behaviour and lipid state were examined in tarantula Brachypelma albopilosa females during the foraging period. Modulation of the agonistic behaviour of females was not connected to their body size. Results show that the agonistic pattern of females differed significantly from the predation pattern at the behavioural and lipid levels.

Mother-pup interactions during a short olfactory deprivation period in young rats.

The effects of short-term bilateral naris occlusion (inducing olfactory deprivation) on mother-pup interactions, suckling behavior and hormonal status during post-natal development in Wistar rats were studied. Bilateral naris occlusion was performed on 8-day-old rat pups and its effects were evaluated at Day 9 and at Day 15. The narins opened spontaneously between Day 12 and 14.

Effects of short term forced oral breathing in rat pups on weight gain, hydration and stress.

Nasal obstruction is a risk factor in sleep-disordered breathing with a negative impact on the quality of life in humans. We investigated hydration changes produced by short term reversible, bilateral, nasal obstruction in young developing rat pups. Physiological parameters of growth (weight gain and gastric content weight) and dehydration were analyzed during two periods; during nasal obstruction at post-natal day 8 (days 9, 11 and 13), plus 7 and 90 days after recovery of nasal breathing (day 15 and adulthood).

Increased ROS production: a component of the longevity equation in the male mygalomorph, Brachypelma albopilosa.

Background: The diversity of longevities encountered in wildlife is one of the most intriguing problems in biology. Evolutionary biologists have proposed different theories to explain how longevity variability may be driven by bad genes expression in late life or by gene pleiotropic effects. This reflexion has stimulated, in the last ten years, an active research on the proximal mechanisms that can shape lifespan.

Differences in Brachypelma albopilosa (Theraphosidae) hemolymph proteome between subadult and adult females.

The changes in the hemolymph proteome of mygalomorph Brachypelma albopilosa females were examined for the first time in relation to their developmental stage (subadult and adult period). Seven distinct subunits of hemocyanin (a, b, c, d, e, f, and g chains), as well as actin were clearly identified and their sequence partly characterized using a combination of one- and two-dimensional gel electrophoresis and mass spectrometry. The different structures determined along with possible post-translational modifications may reflect a role of hemocyanin in molting, immunity, and reproduction.

Role of huddling on the energetic of growth in a newborn altricial mammal.

Huddling is considered as a social strategy to reduce thermal stress and promote growth in newborn altricial mammals. So far, the role of huddling on the allocation of saved energy has not been quantified nor have the related impacts on body temperature rhythms. To determine the energy partitioning of rabbit pups either raised alone or in groups of eight, four, or two individuals, when thermoregulatory inefficient (TI) and efficient (TE), we first investigated their total energy expenditure and body composition.

Effects of early olfactory deprivation on novelty-seeking behavior and primary and secondary lymphoid organs in young rats.

The aim of this study was to investigate the effects of an early olfactory deprivation on novelty-seeking behavior and lymphoid organs during post-natal development in rats. Therefore, we performed a bilateral nasal obstruction on 8-day-old rats and we studied its effects at 21 days of age. Animals exposed to nasal obstruction presented an increased plasma corticosterone level, an adrenal hypertrophy more marked in females (+68% in females and +29% in males compared to sham group), a reduced growth of olfactory bulbs only in females (-43% compared to sham group) and an impaired novelty-seeking behavior, which seemed also more marked in females.

Effect of 20-hydroxyecdysone on cannibalism, sexual behavior, and contact sex pheromone in the solitary female spider, Tegenaria atrica.

We investigated the effect of exogenously administered 20-hydroxyecdysone (20E) on sexual behavior and on contact sex signals of adult females of the spider Tegenaria atrica. In untreated or control females cannibalism occurred in 36-47% of encounters, whereas no cannibalism at all was observed with 20E-treated females. The frequency of sexual receptivity was low (42%) in untreated or control females and high (100%) in 20E-treated females.

The role of 20-hydroxyecdysone on the control of spider vitellogenesis.

We investigated the role of 20-hydroxyecdysone (20E) on the ovarian maturation and protein levels and pattern in adult females of the spider Tegenaria atrica. In unmated females, the ovaries did not initiate vitellogenesis and levels of proteins in the hemolymph and ovaries were low. Unmated females treated with 20E showed an increase in the total amount of proteins in their hemolymph and ovaries, comparable with that in untreated mated females.