Diel activity patterns are often fixed within species such that most animals can be classified as diurnal, crepuscular, or nocturnal, and have sensory abilities that reflect when they are active. However, many snake species appear capable of switching between diurnal and nocturnal activity. Here, we evaluate the hypothesis that some species are constrained in their activity by the sensory cues ...

The sperm of the gastropod Strombus luhuanus show dimorphism. The eusperm have a nucleus and fertilize the egg, whereas the other type of sperm, parasperm, are anucleate and are thought to assist fertilization. Here we report the autonomous changes in the swimming pattern of S. luhuanus eusperm. In artificial seawater, the eusperm collected from S. luhuanus sperm ducts formed sperm bundles and ...

so far, four species of hemidactylus have been reported in iran as follows: h. persicus, h. robustus, h. flaviviridis, h. romeshkanicus. in this study, 108 specimens belonging to these four species of hemidactylus were examined morphologically, using 19 metric and 6 meristic characters. multivariate analyses showed morphological differences among these three species with exception h. romeshkani...

A new species of Trichodoridae, Trichodorus elefjohnsoni, is described from undisturbed regions of Great Smoky Mountains National Park, United States. It resembles T. orientalis De Waele &Hashim, 1984, T. persicus De Waele &Sturhan, 1987, and T. taylori De Waele, Mancini, Roca, ' Lamberti, 1982 in arrangement of ventromedian cervical papillae and posterior preanal supplements, but differs by co...

Although contemporary trends indicative of evolutionary change have been detected in the life-history traits of exploited populations, it is not known to what extent fishing influences the evolution of alternative life-history tactics in migratory species such as salmonids. Here, we build a model to predict the evolution of anadromy and residency in an exploited population of brook charr, Salve...

A short diagnosis and a more detailed diagnosis of the genus Laelaspis are presented. Until now, a total of 40 described species belong to the genus, including a new species described here, and excluding the four following species previously described as Laelaspis or Hypoaspis (Laelaspis): L. badrii Nasr & Nawar [considered as Cosmolaelaps badrii comb. nov.], L. zuluensis Trägårdh, Hypoaspis (L...