Morphological and histological description of the midgut caeca in true crabs (Malacostraca: Decapoda: Brachyura): origin, development and potential role.

Background: The decapods are a major group of crustaceans that includes shrimps, prawns, crayfishes, lobsters, and crabs. Several studies focused on the study of the digestive system of the decapods, constituted by the oesophagus, stomach, midgut tract, midgut gland, and hindgut. Nevertheless, in the midgut tract there are associated a set of organs called "midgut caeca", which are among the most controversial and less studied digestive organs of this group.

Seagrass Posidonia is impaired by human-generated noise.

The last hundred years have seen the introduction of many sources of artificial noise in the sea environment which have shown to negatively affect marine organisms. Little attention has been devoted to how much this noise could affect sessile organisms. Here, we report morphological and ultrastructural changes in seagrass, after exposure to sounds in a controlled environment.

Description of the larval and adult hindgut tract of the common spider crab Maja brachydactyla Balss, 1922 (Brachyura, Decapoda, Malacostraca).

Arthropods are the most diversified animals on Earth. The morphology of the digestive system has been widely studied in insects; however, crustaceans have received comparatively little attention. This study describes the hindgut tract of the common spider crab Maja brachydactyla Balss, 1922, in larvae and adults using dissection, light and electron microscopical analyses.

Polarimetric imaging microscopy for advanced inspection of vegetal tissues.

Optical microscopy techniques for plant inspection benefit from the fact that at least one of the multiple properties of light (intensity, phase, wavelength, polarization) may be modified by vegetal tissues. Paradoxically, polarimetric microscopy although being a mature technique in biophotonics, is not so commonly used in botany. Importantly, only specific polarimetric observables, as birefringence or dichroism, have some presence in botany studies, and other relevant metrics, as those based on depolarization, are underused.

Effects of industrial pollution on the reproductive biology of Squalius laietanus (Actinopterygii, Cyprinidae) in a Mediterranean stream (NE Iberian Peninsula).

Mediterranean rivers are severely affected by pollutants from industry, agriculture and urban activities. In this study, we examined how industrial pollutants, many of them known to act as endocrine disruptors (EDCs), could disturb the reproduction of the Catalan chub (Squalius laietanus). The survey was conducted throughout the reproductive period of S.

Depolarizing metrics for plant samples imaging.

Optical methods, as fluorescence microscopy or hyperspectral imaging, are commonly used for plants visualization and characterization. Another powerful collection of optical techniques is the so-called polarimetry, widely used to enhance image contrast in multiple applications. In the botanical applications framework, in spite of some works have already highlighted the depolarizing print that plant structures left on input polarized beams, the potential of polarimetric methods has not been properly exploited.

Structure of the stomach cuticle in adult and larvae of the spider crab Maja brachydactyla (Brachyura, Decapoda).

The stomach of decapods is a complex organ with specialized structures that are delimited by a cuticle. The morphology and ontogeny of the stomach are largely described, but few studies have focused on the morphology of its cuticle. This study examined the morphology of the stomach cuticle of cardiac sacs, gastric mill ossicles, cardio-pyloric valve and pyloric filters, and during various stages (zoea I and II, megalopa, first juvenile, and adult) of the common spider crab Maja brachydactyla using dissection, histology and transmission electron microscopy.

Morphology and ultrastructure of the midgut gland ("hepatopancreas") during ontogeny in the common spider crab Maja brachydactyla Balss, 1922 (Brachyura, Majidae).

We studied the anatomy and cytology of the midgut gland (MGl) of the common spider crab Maja brachydactyla Balss, 1922 at several life stages (zoea, megalopa, first juvenile, and adult) using dissection, histology, electron microscopy, computed tomography, and micro-computed tomography (micro-CT). In newly hatched larvae, 14 blind-end tubules form the MGl. The length of the tubules increases during the larval development.

Micro-computed tomography and histology to explore internal morphology in decapod larvae.

Traditionally, the internal morphology of crustacean larvae has been studied using destructive techniques such as dissection and microscopy. The present study combines advances in micro-computed tomography (micro-CT) and histology to study the internal morphology of decapod larvae, using the common spider crab (Maja brachydactyla Balss, 1922) as a model and resolving the individual limitations of these techniques. The synergy of micro-CT and histology allows the organs to be easily identified, revealing simultaneously the gross morphology (shape, size, and location) and histological organization (tissue arrangement and cell identification).

Morphology and ultrastructure of the esophagus during the ontogeny of the spider crab Maja brachydactyla (Decapoda, Brachyura, Majidae).

The esophagus of the eucrustaceans is known as a short tube that connects the mouth with the stomach but has generally received little attention by the carcinologists, especially during the larval stages. By this reason, the present study is focused on the morphology and ultrastructure of the esophagus in the brachyuran Maja brachydactyla during the larval development and adult stage. The esophagus shows internally four longitudinal folds.

Foregut morphology and ontogeny of the spider crab Maja brachydactyla (Brachyura, Majoidea, Majidae).

We describe the morphology of the foregut of the spider crab Maja brachydactyla Balss, 1922, from first larval stage to adult, with detailed stage-specific documentation using light and scanning electron microscopy. A total of 40 ossicles have been identified in the foregut of adults of M. brachydactyla using Alizarin-Red staining.

Foregut morphology and ontogeny of the mud crab Dyspanopeus sayi (Smith, 1869) (Decapoda, Brachyura, Panopeidae).

The morphology of the foregut of the Say's mud crab Dyspanopeus sayi was described in adults and larvae. The ossicle system was illustrated based on a staining method with Alizarin-Red. The gastric teeth and cardio-pyloric valve were dissected and examined using optical and scanning electron microscopy.

Histopathology related to cadmium and lead bioaccumulation in chronically exposed wood mice, Apodemus sylvaticus, around a former smelter.

The ceasing of industrial activities often reduces the emission of pollutants but also often leaves disturbed areas without remediation and with persistent pollutants that can still be transferred along the food chain. This study examines the potential relationships between non-essential trace metals and histopathology in target tissues of wood mice (Apodemus sylvaticus) collected along a gradient of contamination around the former smelter, Metaleurop Nord (northern France). Cadmium and lead concentrations were measured, and histological alterations attributable to chronic trace metal exposure were assessed in the liver and the kidneys of 78 individuals.

Ultrastructural damage of Loligo vulgaris and Illex coindetii statocysts after low frequency sound exposure.

There is a considerable lack of information concerning marine invertebrate sensitivity to sound exposure. However, recent findings on cuttlefish and octopi showed that exposure to artificial noise had a direct consequence on the functionality and physiology of the statocysts, sensory organs, which are responsible for their equilibrium and movements in the water column. Owing to a lack of available data on deep diving cephalopod species, we conducted a noise exposure comparative experiment on one Mediterranean squid, Illex coindetii, and on the European squid Loligo vulgaris.

Internal anatomy and ultrastructure of the male reproductive system of the Norway lobster Nephrops norvegicus (Decapoda: Astacidea).

The Norway lobster (Nephrops norvegicus) is economically important in Europe. However, apart from the female reproductive system, very little is known about its internal anatomy. This article focuses on studying the internal anatomy and ultrastructure of the male reproductive system.

Occurrence of somatic cells within the spermatic cysts of demosponges: a discussion of their role.

During ultrastructural studies on the spermatogenesis of two demosponges, Raspaciona aculeata and Petrosia ficiformis, somatic cells were detected within their spermatic cysts. In R. aculeata large, amoeboid somatic cells, presumably derived from follicle cells, were found inside cysts filled with secondary spermatocytes.

Delta de l'Ebre is a natural bay model for Marteilia spp. (Paramyxea) dynamics and life-cycle studies.

Marteilia spp. are paramyxean parasites that affect several bivalve species of economic interest, such as Ostrea edulis and Mytilus galloprovincialis. Certain aspects of Marteilia spp.

Cytological response of hemocytes in the European flat oyster, Ostrea edulis, experimentally exposed to mercury.

Molluscs bivalves have been widely used as bioindicators to monitor contamination levels in coastal waters. In addition, many studies have attempted to analyze bivalve organs, considered pollutant-targets, to understand the bio-accumulation process and to characterize the effects of pollutants on the organisms. Here we analyzed the effects of mercury exposure on flat oyster hemocytes.

Ultrastructural localization of antigenic determinants conserved during Perkinsus atlanticus trophozoite to prezoosporangium differentiation.

Trophozoite, prezoosporangium and zoospore are the 3 main developmental stages that form the life cycle of protozoa of the genus Perkinsus. Several studies have shown that the differentiation of Perkinsus species from the trophozoite to the prezoosporangium stage involves a substantial modification of the antigenic characteristics of these molluscan parasites. With the aim of determining the presence and distribution of antigenic determinants conserved during trophozoite to prezoosporangium differentiation, a polyclonal serum was raised against trophozoites of P.

Vascular involvement and cell damage in experimental AA and clinical beta(2)-microglobulin amyloidosis.

Background: Amyloidosis is a highly prevalent disease characterized by the deposition of amyloid fibrils. Although several types of amyloidosis can be identified according to their protein constituents and suggest putative aetiological factors, the causes of amyloidosis remain unknown. Furthermore, the cellular participation and the ultrastructural particularities of amyloidosis have received little attention.

Characterization and immunolocalization of a main proteinaceous component of the cell wall of the protozoan parasite Perkinsus atlanticus.

Described in the present study is a major component of the cell wall of 2 of the most pathogenic parasites of molluscs, Perkinsus atlanticus and P. marinus. The component is a high molecular weight protein (233 kDa), which we have named PWP-1 (for Perkinsus wall protein-1).

Parasitism by the protozoan Perkinsus atlanticus favours the development of opportunistic infections.

It has been suggested that opportunistic pathogens could contribute to the mortality of Perkinsus atlanticus-infected clams. Examination of Tapes semidecussatus clams from the northern Mediterranean coast of Spain revealed that while 86% of the clams heavily infected with P. atlanticus were co-infected by bacteria and/or viruses, neither non-infected nor lightly P.