Leonor Mendoza-Vargas

We analyzed the abundance, diversity, and distribution of euphausiids and their relationship with hydrodynamic processes from February 2011 to October 2012 in the Campeche Canyon in the southern Gulf of Mexico. Sampling was conducted at 55 oceanographic stations and zooplankton were captured using horizontal trawls. Environmentalvariables (temperat...

The role of melatonin in the synchronization of circadian rhytms, as a regulator of the synchronization process in vertebrates and invetebrates

Melatonin is a metabolite derived from the essential amino acid tryptophan. This biologically active indoleamine is broadly synthesized from bacteria to vertebrates. In animal phyla, melatonin signaling pathways to induce cellular responses seem to be highly conserved. Moreover, this metabolite has been considered as an autocoid, a paracoid or a ho...

Determine whether progeny from these contrasting ecosystems exhibits similitude o divergence in the growth rate as well as in ontogeny of burrowing behavior.

Melatonin (MEL) is an ancient molecule, broadly distributed in nature from unicellular to multicellular species. MEL is an indoleamine that acts on a wide variety of cellular targets regulating different physiological functions. This review is focused on the role played by this molecule in the regulation of the circadian rhythms in crayfish. In the...

Main physiological functions such as cell proliferation, metabolism, growth, immune response, reproduction, and behaviors follow a circadian rhythm. These regular oscillations require their orchestration in order to gain in homeostasis and health, and the temporal coordination of these depends on reciprocal signaling among the hierarchically organi...

Melatonin (MEL) is a conserved molecule with respect to its synthesis pathway and functions. In crayfish, MEL content in eyestalks (Ey) increases at night under the photoperiod, and this indoleamine synchronizes the circadian rhythm of electroretinogram amplitude, which is expressed by retinas and controlled by the cerebroid ganglion (CG). The aim...

Aspects of Procambarus acanthophorus burrowing behavior were studied by an interdisciplinary investigation group, which approached different aspects of the biology of this crayfish. Three topics are emphasize including, the description of its habitat; the impact of the flooding dynamic on the population and the physiology of P acanthophorus, and th...

Catch size, sex ratio, structure and dynamics, as well as mortality, of a population of the secondary burrower crayfish Procambarus acanthophorus Villalobos, 1948, from tropical wetland La Mixtequilla, Veracruz, Mexico, were examined. Monthly samples were taken from artisanal commercial captures. A total of 2141 individuals were caught. Although th...

The native crayfish Procambarus acanthophorus (Villalobos, 1948) is geographically distributed in Southeast Mexico, in the states Veracruz, Oaxaca, and Chiapas. This crayfish inhabits freshwater ecosystems such as creeks, lagoons, and wetlands. Procambarus acanthophorus builds and inhabits complex burrows during dry periods and lives in open water...

Crayfish Procambarus acanthophorus is a burrower that spends long periods building deep tunnels to reach the water table during the dry season; thus, its survival entertains a close ecological relationship with the sediment. The aim of this work was to determine whether the properties of the circadian rhythm of locomotor activity could be modified...

In crayfish, the supraoesophageal ganglion and the retina are neuronal structures whose electrical activities follow a circadian rhythm. The hormone melatonin (MEL) is an indoleamine, conserved from unicellular organisms to mammals, that is released rhythmically with a peak occurring in the darkness period. In vertebrates, MEL acts on numerous cent...

In crayfish, one very well-studied circadian rhythm is that of electroretinogram (ERG) amplitude. The cerebroid ganglion has been considered a plausible site for the circadian pacemaker of this rhythm and for the retinular photoreceptors, as the corresponding effectors. The pigment dispersing hormone (PDH) appears to synchronize ERG rhythm, but its...

Retinular photoreceptors are structures involved in the expression and synchronization of the circadian rhythm of sensitivity to light in crayfish. To determine whether melatonin possesses a differential effect upon the receptor potential (RP) amplitude of retinular photoreceptors circadian time (CT)-dependent, we conducted experiments by means of...

One of the most important functions modulated by melatonin is the synchronization of circadian rhythms. In crayfish (Procambarus clarkii), we have obtained evidence that the amplitude of the electrical response to light of the retinal photoreceptors the receptor potential, is modified by the action of melatonin and that the magnitude of this action...