Issues

Summary: Here, we consider insights into muscle mechanics based on new ideas about the giant protein titin as a tunable viscoelastic element in active muscles, and discuss implications for design and control of robotic prostheses.

Summary: This Review examines why developmental stress studies in the avian taxa show conflicting results, identifies benefits and costs of developmental stressors and recommends future studies in the field.

Highlighted Article: Unlike hypoxia-tolerant rodents inhabiting similar niches, star-nosed moles are intolerant to hypoxia, which may reflect an evolutionary trade-off favouring the extreme sensory biology of this unusual insectivore.

Summary: Molecular markers of memory formation, CREB, CamKII and fen-1, are expressed similarly in the mushroom bodies and optic lobes of honey bees following visual aversive conditioning.

Highlighted Article: Mussels repair shell damage caused by fatigue within one week and further strengthen shells within one month. Bivalve shells are a dynamic armor, responsive to accumulating weakening damage.

Highlighted Article: High aerobic activity is linked to an accrual of oxidative damage and greater costs associated with protein turnover.

Summary: Stability of the social environment influences oxidative balance in dominant and subordinate males in a tissue- and marker-specific manner in experimental groups of cichlid fish.

Highlighted Article: Near-infrared reflectivity and body size have important thermal effects on radiative heat gain in jewel beetles.

Summary: Multiple Anolis lineages independently evolved a similar skin surface microarchitecture with water-repellent properties as an adaptation to a semi-aquatic lifestyle.

Highlighted Article: In the field, male water voles show dramatic seasonal changes in morphological and neuroendocrine markers along the hypothalamo–pituitary–gonadal axis, which are strongly influenced by photoperiod as shown under controlled laboratory conditions.

Summary: A novel example of influences of gut-microbial communities on host phenotype indicates how gut symbionts modulate phenotypic plasticity in a eusocial super-organism.

Summary: Theoretical analysis and experimental evidence, in addition to previous EMG studies, indicate that finger flexors are likely not involved in buffering ground impact in chimpanzee knuckle walking.

Summary: Acute low temperature exposure and anoxia alter electrical properties in turtle pyramidal neurons similarly. However, acute low temperature exposure lengthens repolarization time, but acclimation to low temperature reverses it.

Summary: Electric fish adjust their competition behavior according to mutual assessment, where electrocommunication with so-called ‘rises’ could signal a loser's motivation to continue assessment through ritualized fighting.

Summary: Flamingos change limb kinematics such as step height and limb joint angle as speed and water depth change, with higher steps in intermediate depths that may reduce drag imposed by water.

Summary: Investigation of the heat-hardening responses in intertidal bivalves after acclimatization to warm seasons highlights the mediating role of membrane lipid metabolism, heat shock responses and energy costs in the interaction between the heat-hardening responses and seasonal acclimatization.

Editor's Choice: Integrating safety cues into the landscape of fear models of predator–prey interactions can provide a more thorough understanding of animal decision making. Crayfish use safety cues associated with shelters in high risk situations but not in low risk events.

Summary: Existing animal magnetoreception models are either light dependent or light independent. Cryptochrome protein (Cry) is at the center of the light-dependent mechanism. Interestingly, the firebug Pyrrhocoris apterus shows both Cry-dependent and darkness-resistant magnetoreception.

Summary: SALMFamide neuropeptide can regulate the locomotor behavior of sea cucumbers; muscle metabolic physiology after SALMFamide treatment indicates potential physiological mechanisms underlying this regulation.