Search results for "decapod"

Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852).

1994

Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g…

Changes in biochemical composition of gills, hepatopancreas and muscle of the red crayfish Procambarus clarkii (Girard) after sublethal exposure to m…

1992

Abstract 1. 1. The changes in the biochemical composition of gills, hepatopancreas and muscle after exposure to 0.25 mg Hg/l were studied in Procambarus clarkii . 2. 2. Sublethal exposure to mercury in P. clarkii resulted in significant decreases in protein concentration and caloric concentration in gills over the 96 hr period. Glycogen/lipid and glycogen/protein ratios increased after 48 and 96 hr of mercury exposure. 3. 3. Lipid and caloric concentration in the hepatopancreas were significantly lower in 96 hr mercury exposed group. 4. 4. Glycogen concentration in muscle was depleted as consequence of 96 hr mercury exposure.

Acute toxicity and oxygen consumption in the gills of Procambarus clarkii in relation to chlorpyrifos exposure.

1992

Histological and electron microscopical observations on the effects of lead on gills and midgut gland ofProcambarus clarkii

1991

Adult intermolt specimen of Procambarus clarkii (Crustacea, Decapoda) have been treated for 96 hours in aquaria with 100mg/l of lead. The gills and midgut gland were processed and studied in the electron microscope. The gill filament shows important changes in the ultrastructure of the epithelial cells and the cuticle. The hepatopancreatic cells studied (i.e. the vacuolated and dark cells) do not show noticeable structural changes but accumulate lead (electrondense precipitates) mainly in lysosomes.

Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues.

1988

The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Al…

Effects of cadmium on the biochemical composition of the freshwater crayfishProcambarus clarkii (Girard, 1852)

1991

Lake Albufera of Valencia (Spain) and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic residues. Among these residues include heavy metals which have been deposited from the many urban and waste waters in this area. The American red crayfish, Procambarus clarkii from Albufera Lake has high resistance to heavy metals. The authors have also found that P. clarkii shows a high capacity for cadmium accumulation in experimental conditions and natural conditions since crayfish collected in this area contained considerable amounts of cadmium in several tissues even after 15 days of depuration in clean water. Since the physiological changes that take place when…

In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Ce…

2021

AbstractIn total, 90 gelatinous spheres, averaging one meter in diameter, have been recorded from ~ 1985 to 2019 from the NE Atlantic Ocean, including the Mediterranean Sea, using citizen science. More than 50% had a dark streak through center. They were recorded from the surface to ~ 60–70 m depth, mainly neutrally buoyant, in temperatures between 8 and 24°C. Lack of tissue samples has until now, prohibited confirmation of species. However, in 2019 scuba divers secured four tissue samples from the Norwegian coast. In the present study, DNA analysis using COI confirms species identity as the ommastrephid broadtail shortfin squid Illex coindetii (Vérany, 1839); these are the first confirmed …

Determination of mercury by cold‐vapour technique in several tissues of treated American red crayfish (Procambarus clarkii)

1988

Abstract Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg‐concentrations used were 50, 100, and 250 μg Hg/1 as Cl2Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold‐vapour technique and AAS. The mercury levels in all examinated tissues increased significantly (ANOVA test, p < 0.01) with increasing Hg‐concentration in the water.

Reversible stress softening of collagen based networks from the jumbo squid mantle (Dosidicus gigas).

2014

Dosidicus gigas is the largest and one of the most abundant jumbo squids in the eastern Pacific Ocean. In this paper we have studied the muscle of the mantle of D. gigas (DGM). Morphological, thermal and rheological properties were assessed by means of atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry and oscillatory rheometry. This study allowed us to assess the morphological and rheological properties of a collagen based network occurring in nature. The results showed that the DGM network displays a nonlinear effect called reversible stress softening (RSS) that has been previously described for …

Further investigations on populations of the deep-water blue and red shrimp Aristeus antennatus (Risso, 1816) (Decapoda, Dendrobranchiata), as inferr…

2012

The aim of this study was to integrate existing mitochondrial DNA data relating to the deep-sea blue and red shrimp Aristeus antennatus (Risso, 1816) with data obtained by Amplified Fragment Length Polymorphism (AFLP). A total of 145 AFLP polymorphic loci were scored in 236 specimens collected from one Atlantic and seven Mediterranean sample sites. AMOVA results revealed that the overall genetic variation among-populations was lower (11.81%) than within-populations (88.19%). The genetic variation between the Atlantic and Mediterranean samples was found to be not significant ( Φ CT = − 0 . 007 ; N.S.), indicating that the transition area between the Atlantic Ocean and the Mediterranean Sea d…