Kinetic comparisons of jaw opening, jaw closing and locomotor muscles.

Understanding contraction dynamics of skeletal muscle is critically important to appreciate performance capabilities of skeletal structures, especially for structures responsible for feeding and/or locomotion. Furthermore, it is important to understand how temperature can impact contraction dynamics in vertebrates that are regularly exposed to fluctuations in temperature. We aimed to address differences between jaw opening (sternhyoideus), jaw closing (adductor mandibulae) and locomotor (abductor superficialis) muscle contraction dynamics in a labrid fish.

Impacts of thermal acclimatization on fish skeletal muscle.

Thermal acclimation allows ectotherms to maintain physiological homeostasis while occupying habitats with constantly changing temperatures. This process is especially important in skeletal muscle which powers most movements necessary for life. We aimed to understand how fish skeletal muscle is impacted by acclimatization in the laboratory.

Thermal acclimation leads to variable muscle responses in two temperate labrid fishes.

Temperature can be a key abiotic factor in fish distribution, as it affects most physiological processes. Specifically, temperature can affect locomotor capabilities, especially as species are exposed to temperatures nearing their thermal limits. In this study, we aimed to understand the effects of temperature on muscle in two labrids that occupy the Northwest Atlantic Ocean.

Effects of overwintering temperatures on the escape response in cunner (Tautogolabrus adspersus).

Cunner (Tautogolabrus adspersus) are a temperate labrid species that inhabit the Western Atlantic and experience temperatures ranging from 0°C to 25°C. During autumn, once temperatures drop below 10°C in Long Island Sound, cunner find shelter and enter a state of quiescence. Previous work has shown that acclimation to low temperatures limits the performance of locomotor musculature, which significantly lowers steady swimming capabilities.

Temperature constrains locomotion and muscle function in two temperate labrids.

Winter quiescence in fishes is not uncommon, however understanding the mechanisms that cause dormancy are poorly understood. This study highlights the physiological stress temperature places on locomotor musculature and its consequences on whole organism locomotion. Cunner and tautog experience temperatures ranging from 0 to 25 °C and enter dormancy at ~10 °C.

Behavioral and physiological adaptations to high-flow velocities in chubs ( spp.) native to Southwestern USA.

Morphological streamlining is often associated with physiological advantages for steady swimming in fishes. Though most commonly studied in pelagic fishes, streamlining also occurs in fishes that occupy high-flow environments. Before the installation of dams and water diversions, bonytail (Cyprinidae, ), a fish endemic to the Colorado River (USA), regularly experienced massive, seasonal flooding events.

Scaling of the fast-start escape response of juvenile bluegills.

Morphology, size and physiological properties change markedly across fish ontogeny. This impacts locomotor performance and organismal fitness, although the effects are unpredictable due to the complexity of phenotype-function relationships. Morphological and behavioral changes with growth are often paralleled by changes in habitat use, diet and vulnerability to predators.

Resolving shifting patterns of muscle energy use in swimming fish.

Muscle metabolism dominates the energy costs of locomotion. Although in vivo measures of muscle strain, activity and force can indicate mechanical function, similar muscle-level measures of energy use are challenging to obtain. Without this information locomotor systems are essentially a black box in terms of the distribution of metabolic energy.

Variation in fast-start performance within a population of polyphenic bluegill (Lepomis macrochirus).

Bluegill sunfish Lepomis macrochirus exhibit intraspecific variation in their morphology and swimming performance based on habitat. The pelagic form has a relatively streamlined, fusiform body shape associated with greater steady-state swimming speed and energy economy. In contrast, littoral bluegill have deeper bodies with fins located farther from their center of mass to enhance maneuverability among littoral vegetation.

Serotonin as an integrator of leech behavior and muscle mechanical performance.

The obliquely striated muscle in the leech body wall has a broad functional repertoire; it provides power for both locomotion and suction feeding. It also operates over an unusually high strain range, undergoing up to threefold changes in length. Serotonin (5-HT) may support this functional flexibility, integrating behavior and biomechanics.

The seed dispersal catapult of Cardamine parviflora (Brassicaceae) is efficient but unreliable.

Premise Of The Study: Seed dispersal performance is an essential component of plant fitness. Despite their significance in shaping performance, the mechanical processes that drive dispersal are poorly understood. We have quantified seed dispersal mechanics in Cardamine parviflora (Brassicaceae), a ballistic disperser that launches seeds with specialized catapult-like structures.

Serotonin modulates muscle function in the medicinal leech Hirudo verbana.

The body wall muscles of sanguivorous leeches power mechanically diverse behaviours: suction feeding, crawling and swimming. These require longitudinal muscle to exert force over an extremely large length range, from 145 to 46 per cent of the mean segmental swimming length. Previous data, however, suggest that leech body wall muscle has limited capacity for force production when elongated.

Evolution of asynchronous motor activity in paired muscles: effects of ecology, morphology, and phylogeny.

Many studies of feeding behavior have implanted electrodes unilaterally (in muscles on only one side of the head) to determine the basic motor patterns of muscles controlling the jaws. However, bilateral implantation has the potential to achieve a more comprehensive understanding of modification of the motor activity that may be occurring between the left and right sides of the head. In particular, complex processing of prey is often characterized by bilaterally asynchronous and even unilateral activation of the jaw musculature.