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...

argas reflexus is considered obligate blood feeder that may cause skin redness and local swelling. for histopathological evaluation of biting site, pigeons were used as natural host species in this study. adult ticks were collected from urmia, north-west of iran and kept in a desiccator before their use in the experiment. sixteen pigeons were infested experimentally and were divided into 4 grou...

Fish skin is essential for survival, maintenance of body shape, and protection against the shock and infection. During week 1 of sturgeon larval development, the epidermis is thin and not differentiated in various layers yet, but by week 4-6 the thickness increases and various layers appear, depending upon the region of the body. Mucous cells differentiate early in development on the surface of...

This study reports the experimental transmission of Borrelia anserina to domestic chickens by infected Argas (Persicargas) miniatus. Clinical alterations as well as prepatent and patent periods were evaluated. Twenty-seven 67-day-old birds were divided into three groups in a randomized experimental design. The first group was exposed to ticks infected with B. anserina, the second group was expo...

During winter populations of Argas arboreus from heronries of the cattle egret, Bubulcus ibis, in South Africa are composed of adults, with some predominance of males, and II-IV instar nymphs, in a state of diapause. The period of tick activity, including reproduction and development of eggs, larvae and N1 nymphs, is synchronized with the nesting and breeding season of their avian hosts. It beg...