Water monitor lizards (Varanus salvator) swim using sinusoidal oscillations generated at the base of their long (50% of total body length) tail. In an effort to determine which level of the structural/organizational hierarchy of muscle is associated with functional segregation between the muscles of the tail base, an array of muscle features—myosin heavy chain profiles, enzymatic fiber types, twitch and tetanic force production, rates of fatigue, muscle compliance, and electrical activity patterns—were quantitated. The two examined axial muscles, longissimus, and iliocaudalis, were generally similar at the molecular, biochemical, and physiological levels, but differed at the biomechanics level and in their activation pattern. The appendicular muscle examined, caudofemoralis, differed from the axial muscles particularly at the molecular and physiological levels, and it exhibited a unique compliance profile and pattern of electrical activation. There were some apparent contradictions between the different structural/organizational levels examined. These contradictions, coupled with a unique myosin heavy chain profile, lead to the hypothesis that there are previously un-described molecular/biochemical specializations within varanid skeletal muscles.

Courtship in male Pardosa xerampelina is stimulated by a contact sex pheromone laid down by the female, though visual cues also play a part. There is a short period of immobility, followed by the extension and raising of the pedipalps, one after the other. The male then makes a short run toward the female, his tarsi making an audible sound on the substratum. This sequence is repeated one or more times until the male is very close to the female, when he drums on the substratum (also producing a sound), taps the legs and cephalothorax of the female with his anterior legs, and mounts at once.