The occurrence of melatonin is known in nearly all organisms, hut nothing is known exactly about its function outside of vertebrates. Long-term perifusions as well as short-term batch incubations of brains and moulting glands of the cockroach Peri­ planeta americana were used to identify the effect of melatonin on the release of prothoracicotropic hormone, a glandotropic neuro­ peptide in the b...

Precopulatory mate guarding is a common strategy, which has evolved in species where the female receptivity (and thus egg fertilization) is predictable, but also limited to a short period. Although males are larger than females in many amphipods, the largest males pair with the largest females, leading to a positive sizeassortative pairing. Size-assortative pairing has received much attention b...

A 365 million year-old trilobite moult-carcass assemblage was described by Błażejowski et al. (2015) as the oldest direct evidence of moulting in the arthropod fossil record. Unfortunately, their suppositions are insufficiently supported by the data provided. Instead, the morphology, configuration and preservational context of the highly fossiliferous locality (Kowala Quarry, Poland) suggest th...

We investigated the effect of moult speed on the expression of a sexually selected, carotenoid-based feather ornament in the rock sparrow (Petronia petronia). We experimentally accelerated the moult speed of a group of birds by exposing them to a rapidly decreasing photoperiod and compared the area and the spectral characteristics of their ornaments with those of control birds. Birds with accel...

Studies of brilliant carotenoid-based coloration in birds have traditionally centred on the role that these colours play in attracting mates. More recently, biologists have begun to take a biochemical approach to understanding the types of pigments found in feathers and how these relate to the expression of ornamental coloration. Nevertheless, surprisingly few studies have assessed the types an...

Moulting is a cornerstone of arthropods development. It can be determined by numerous factors such as body mass, temperature, and immunity. However, the effects these dependent on each other, so that it often difficult to predict whether how they shape moulting, their are additive or interactive. In this study, we addressed questions testing ambient fungal infection interaction intermoult durat...

Reconsideration of the position of trilobite-like arthropods leads to an idea of the last shared ancestor of known (eu)arthropods. The ancestry and morphological evolution is traced back from this form to a hypothetical ciliated and pseudosegmented slug-like ancestor. Evolution logically passed through a lobopodian stage. Extant onychophorans, Cambrian xenusians, and perhaps anomalocaridids wit...

Three major bilaterian clades first appear in the Early Cambrian fossil record: Deuterostomia, Lophotrochozoa, and Ecdysozoa. The taxa placed in Ecdysozoa are characterized by a moulting habit, unknown in the other major clades. The origin and consequences of moulting are of fundamental importance to the history of the ecdysozoan clade, chiefly because moulting precludes motile ectodermal cilia...