Seasonal digestive gland dynamics of the scallop Pecten maximus in the Bay of Brest (France)

2001 ◽  
Vol 81 (4) ◽  
pp. 663-671 ◽  
Author(s):  
Gaël Le Pennec ◽  
Marcel Le Pennec ◽  
G. Beninger
Keyword(s):  
Digestive Gland ◽  
Cell Structure ◽  
Shell Growth ◽  
Adductor Muscle ◽  
Early Spring ◽  
Lipid Storage ◽  
Pecten Maximus ◽  
Bay Of Brest ◽  
One Year ◽  
Acinar Lumen

Cytological and biochemical changes in the digestive gland of Pecten maximus throughout a one-year period were investigated in the Bay of Brest (France) relative to lipid storage and glycogen and α-amylase concentrations in tubuloacinar terminations. Seasonal variations in both cell structure and biochemical composition were observed. These changes were independent of the tidal cycle, but correspond to phytoplankton abundance. From November to January, cells of digestive acini were hypertrophied due to the high lipid storage. From February to May, these reserves were markedly reduced, cell size decreased, and the acinar lumen was clearly apparent. From May to September, the RNAs transcribing for α-amylase increased, and a correlation was found between digestion events and lipid storage in acinar cells. The relationships between metabolite transfers from digestive gland to gonad and other tissues are described. Distinct lipid storage sites appear to be associated with maintenance energy and acute demand energy, such as gametogenesis when adductor muscle reserves have been depleted. The digestive gland may thus function as a relay organ during periods of energetic stress, notably during the first gametogenesis in February and March and for shell growth in early spring.

scholarly journals Growth anomalies in Pecten maximus from coastal waters (Bay of Brest, France): relationship with diatom blooms

2000 ◽  
Vol 80 (4) ◽  
pp. 667-673 ◽  
Author(s):  
Anne Lorrain ◽  
Yves-Marie Paulet ◽  
Laurent Chauvaud ◽  
Nicolas Savoye ◽  
Elisabeth Nézan ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Quantitative Description ◽  
Bottom Layer ◽  
Oxygen Depletion ◽  
Limiting Factors ◽  
Pecten Maximus ◽  
High Concentration ◽  
Bay Of Brest ◽  
Diatom Blooms

The aim of this study was to characterize the daily shell growth of Pecten maximus from early 1998 to late spring 1999 in the Bay of Brest with a careful qualitative and quantitative description of the pelagic primary production. Our results, in accordance with previous studies, demonstrate that there are episodic declines in the growth rate. Concurrent events of low growth rate and large bottom-concentrations of algae following diatom blooms (Cerataulina pelagica or Rhizosolenia delicatula), suggests that this high concentration of phytoplankton on the bottom layer may affect food intake or respiratory activity of the scallops by gill clogging or oxygen depletion. In this study, silicic acid or phosphorus are inferred to be limiting factors responsible for the collapse of the spring bloom. Further, we suggest that, in an N-enriched ecosystem, Si or P-limitation and the changing sinking velocities of phytoplankton, could affect the biology of benthic suspension-feeders.

scholarly journals Transcriptional Response in the Digestive Gland of the King Scallop (Pecten maximus) after the Injection of Domoic Acid

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 339
Author(s):  
Pablo Ventoso ◽  
Antonio J. Pazos ◽  
Juan Blanco ◽  
M. Luz Pérez-Parallé ◽  
Juan C. Triviño ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Gene Ontology ◽  
Immune System ◽  
Digestive Gland ◽  
Domoic Acid ◽  
Differentially Expressed ◽  
Pecten Maximus ◽  
System Process ◽  
Immune System Process ◽  
Response To Stress

Some diatom species of the genus Pseudo-nitzschia produce the toxin domoic acid. The depuration rate of domoic acid in Pecten maximus is very low; for this reason, king scallops generally contain high levels of domoic acid in their tissues. A transcriptomic approach was used to identify the genes differentially expressed in the P. maximus digestive gland after the injection of domoic acid. The differential expression analysis found 535 differentially expressed genes (226 up-regulated and 309 down-regulated). Protein–protein interaction networks obtained with the up-regulated genes were enriched in gene ontology terms, such as vesicle-mediated transport, response to stress, signal transduction, immune system process, RNA metabolic process, and autophagy, while networks obtained with the down-regulated genes were enriched in gene ontology terms, such as response to stress, immune system process, ribosome biogenesis, signal transduction, and mRNA processing. Genes that code for cytochrome P450 enzymes, glutathione S-transferase theta-1, glutamine synthase, pyrroline-5-carboxylate reductase 2, and sodium- and chloride-dependent glycine transporter 1 were among the up-regulated genes. Therefore, a stress response at the level of gene expression, that could be caused by the domoic acid injection, was evidenced by the alteration of several biological, cellular, and molecular processes.

Sterol composition of gonad, muscle and digestive gland of Pecten maximus from Málaga (South Spain)

2003 ◽  
Vol 134 (3) ◽  
pp. 435-446 ◽  
Author(s):  
A.J Pazos ◽  
A Silva ◽  
V Vázquez ◽  
M.L Pérez-Parallé ◽  
G Román ◽  
...  
Keyword(s):  
Digestive Gland ◽  
Sterol Composition ◽  
Pecten Maximus

scholarly journals The effect of the queen's age on the Varroa mite (Varroa destructor) burden of honey bee (Apis mellifera L.) colonies

2018 ◽  
pp. 83-87
Author(s):  
Marianna Takács ◽  
János Oláh
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Early Spring ◽  
Brood Chamber ◽  
One Year ◽  
The One ◽  
Post Hoc ◽  
Bee Colonies ◽  
Mite Mortality

An apiary trial was conducted in 2016 August to October in Szabolcs-Szatmár-Bereg County, Nyírmada to evaluate the influence of queen’s age on the Varroa destructor-burden in the treatment colonies. Sixty colonies of bees belonging to the subspecies Apis mellifera carnica pannonica in Hunor loading hives (with 10 frames in the brood chamber/deep super) were used. The colonies were treated with amitraz and the organophosphate pesticide coumaphos active ingredients. The amitraz treatment includes 6 weeks. The coumaphos treatment with Destructor 3.2% can be used for both diagnosis and treatment of Varroasis. For diagnosis, one treatment is sufficient. For control, two treatments at an interval of seven days are required. The colonies were grouped by the age of the queen: 20 colonies with one-year-old, 20 colonies with two-year-old and 20 colonies with three-year-old queen. The mite mortality of different groups was compared. The number of fallen mites was counted at the white bottom boards. The examination of spring growth of honey bee colonies has become necessary due to the judgement of efficiency of closing treatment. The data was recorded seven times between 16th March 2017 and 19th May 2017. Data on fallen mites were subjected to one-way analysis of variance (ANOVA) and Post-Hoc Tukey-test. Statistical analysis was performed using the software of IBM SPSS (version 21.). During the first two weeks after treatments, the number of fallen mites was significantly higher in the older queen’s colonies (Year 2014). The total mite mortality after amitraz treatment in the younger queen’s colonies was lower (P<0.05) compared to the three-year-old queen’s colonies. According to Takács and Oláh (2016) although the mitemortality tendency, after the coumaphos (closing) treatment in colonies which have Year 2014 queen showed the highest rate, considering the mite-burden the colonies belongs to the average infected category. The colonial maintenance ability of three-year-old queen cannot be judged based on the influencing effect on the mite-burden. The importance of the replacement of the queen was judged by the combined effect of several factors. During the spring-growth study (16th March–19th May) was experienced in the three-year-old queen’s colonies the number of brood frames significantly lower compared to the one- and two-year-old queen’s colonies. In the study of 17th April and 19th May each of the three queen-year-groups were varied. Therefore in the beekeeping season at different times were determined the colonial maintenance ability of queens by more factors: efficiency of closing treatment in early spring, the spring-growth of bee colonies, the time of population shift (in current study, this time was identical in each queen-year), honey production (from black locust).

scholarly journals Sexual maturation in Atlantic salmon male parr may be triggered both in early spring and late summer under standard farming conditions

2021 ◽  
Author(s):  
Elia Ciani ◽  
Kristine von Krogh ◽  
Rasoul Nourizadeh-Lillabadi ◽  
Ian Mayer ◽  
Romain Fontaine ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Sexual Maturation ◽  
Late Summer ◽  
Early Spring ◽  
Plasma Testosterone ◽  
Farmed Salmon ◽  
Early Maturing ◽  
Advanced Stages ◽  
One Year ◽  
Immature Fish

AbstractMale Atlantic salmon (Salmo salar) display different sexual strategies, maturing either as parr during the freshwater phase (as sneaky spawners), or as post smolts following one or several years at sea. First sexual maturation (puberty) occurs at different times depending on environmental and genetic factors. To improve our knowledge on the timing (age and season) of first sexual maturation in Atlantic salmon male parr, we investigated pubertal activation in second generation farmed salmon from the Norwegian river Figgjo, reared under natural conditions of photoperiod and water temperature. Histological analysis, in combination with morphometric measurements, plasma androgen levels and pituitary gonadotropin gene expression analysis revealed that, as previously reported, some male parr initiated early sexual maturation in spring at one year of age. Interestingly, some male parr were observed to initiate sexual maturation already in autumn, six months after hatching (under-yearlings), much earlier than reported in previous studies. One-year old maturing males showed a low induction in gonadotropin levels, while under-yearling maturing males displayed a significant increase in fshb transcripts as compared to immature fish. Plasma testosterone, detectable also in immature males, increased constantly during testes development, while 11-ketotestosterone, undetectable in immature and early maturing males, increased during more advanced stages of maturation. A mild feminization of the testes (ovotestes) was detected in a subset of samples. This study brings new knowledge on the little investigated field of sexually maturing under-yearlings in Atlantic salmon. This is also the first study comparing the physiology of under-yearling vs one-year old maturing male parr, thus bringing new insights to the remarkable plasticity of Atlantic salmon puberty.

scholarly journals High frequency Barium profiles in shells of the Great Scallop <i>Pecten maximus</i>: a methodical long-term and multi-site survey in Western Europe

2008 ◽  
Vol 5 (5) ◽  
pp. 3665-3698 ◽  
Author(s):  
A. Barats ◽  
D. Amouroux ◽  
L. Chauvaud ◽  
C. Pécheyran ◽  
A. Lorrain ◽  
...  
Keyword(s):  
High Frequency ◽  
Western Europe ◽  
Pecten Maximus ◽  
Coastal Environments ◽  
Great Scallop ◽  
Site Survey ◽  
Scallop Shells ◽  
Bay Of Brest ◽  
Long Term Survey

Abstract. Skeletal barium/calcium ([Ba]/[Ca])shell ratios were measured every third daily striae in 39 flat valves of the Great Scallop Pecten maximus (2-year old; 3 shells/year) collected in temperate coastal environments of Western Europe. Variations of ([Ba]/[Ca])shell ratio were first demonstrated reproducible for several scallop individuals from the same population, over a 7-year period (1998–2004), and from different coastal environments in France (42–49° N). As in previous studies, ([Ba]/[Ca])shell profiles exhibited a background ratio punctuated by transient maxima occurring in summer. Background partition coefficient (DBa=0.11±0.03, in 2000) was similar to that previously reported in P. maximus shells (DBa=0.18), suggesting a direct shell uptake of dissolved seawater Ba (Gillikin et al., 2008). Special attention was then dedicated to the complete monitoring of high resolution ([Ba]/[Ca])shell profiles in bivalve shells (7 years, Bay of Brest) to better constrain environmental processes influencing both the occurrence and the amplitude of summer peaks. In 2000, seawater Ba analyses underlined significant particulate Ba inputs at the seawater interface (SWI) during ([Ba]/[Ca])shell peak events. These Ba inputs are suggested to be subsequent to and rather induced by a pelagic biogenic process. The long term survey revealed first that archived Ba within the shell cannot be used as a direct paleo productivity tracer, and second that complex pelagic/benthic processes in the Ba cycle are responsible of particulate Ba inputs to the SWI, subsequently taken up by the bivalve and recorded as higher ([Ba]/[Ca])shell ratios. When these processes will be better constrained, high frequency observations of Ba in scallop shells would provide new insights into filter feeding dynamics and into Ba biogeochemistry in coastal environments.

scholarly journals Variation in brachiopod microstructure and isotope geochemistry under low pH–ocean acidification–conditions

2018 ◽  
Author(s):  
Facheng Ye ◽  
Hana Jurikova ◽  
Lucia Angiolini ◽  
Uwe Brand ◽  
Gaia Crippa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Ocean Acidification ◽  
Isotope Geochemistry ◽  
Shell Growth ◽  
Low Ph ◽  
Secondary Layer ◽  
Ph Conditions ◽  
One Year ◽  
The Impact ◽  
Δ13c And Δ18o

Abstract. Throughout the last few decades and in the near future CO2–induced ocean acidification is potentially a big threat to marine calcite-shelled animals (e.g., brachiopods, bivalves, corals and gastropods). Despite the great number of studies focusing on the effects of acidification on shell growth, metabolism, shell dissolution and shell repair, the consequences on biomineral formation remain poorly understood, and only few studies addressed contemporarily the impact of acidification on shell microstructure and geochemistry. In this study, a detailed microstructure and stable isotope geochemistry investigation was performed on nine adult brachiopod specimens of Magellania venosa (Dixon, 1789), grown in the natural environment as well as in controlled culturing experiments at different pH conditions (ranging 7.35 to 8.15 ± 0.05) over different time intervals (214 to 335 days). Details of shell microstructural features, such as thickness of the primary layer, density and size of endopunctae and morphology of the basic structural unit of the secondary layer were analysed using scanning electron microscopy (SEM). Stable isotope compositions (δ13C and δ18O) were tested from the secondary shell layer along shell ontogenetic increments in both dorsal and ventral valves. Based on our comprehensive dataset, we observed that, under low pH conditions, M. venosa produced a more organic-rich shell with higher density of and larger endopunctae, and smaller secondary layer fibres, when subjected to about one year of culturing. Also, increasingly negative δ13C and δ18O values are recorded by the shell produced during culturing and are related to the CO2–source in the culture setup. Both the microstructural changes and the stable isotope results are similar to observations on brachiopods from the fossil record and strongly support the value of brachiopods as robust archives of proxies for studying ocean acidification events in the geologic past.

scholarly journals Distribution of Domoic Acid in the Digestive Gland of the King Scallop Pecten maximus

Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 371
Author(s):  
Juan Blanco ◽  
Aida Mauríz ◽  
Gonzalo Álvarez
Keyword(s):  
Digestive Gland ◽  
Domoic Acid ◽  
Time Course ◽  
Cell Types ◽  
Individual Variability ◽  
Small Cells ◽  
Intestinal Loop ◽  
Pecten Maximus ◽  
Shellfish Poisoning ◽  
Long Time

The king scallop Pecten maximus retains the amnesic shellfish poisoning toxin, domoic acid (DA), for a long time. Most of the toxin is accumulated in the digestive gland, but this organ contains several cell types whose contribution to the accumulation of the toxin is unknown. Determining the time-course of the depuration by analyzing whole organs is difficult because the inter-individual variability is high. A sampling method, using biopsies of the digestive gland, has been developed. This method allows for repetitive sampling of the same scallop, but the representativeness of the samples obtained in this way needs to be validated. In this work, we found that the distribution of DA in the digestive gland of the scallops is mostly homogeneous. Only the area closest to the gonad, and especially its outer portion, had a lower concentration than the other ones, probably due to a transfer of the toxin to the intestinal loop. Samples obtained by biopsies can therefore be considered to be representative. Most of the toxin was accumulated in large cells (mostly digestive cells), which could be due to differences during the toxin absorption or to the preferential depuration of the toxin from the small cells (mostly secretory).

scholarly journals Paralytic Shellfish Toxins in Surf Clams Mesodesma donacium during a Large Bloom of Alexandrium catenella Dinoflagellates Associated to an Intense Shellfish Mass Mortality

Toxins ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 188 ◽  
Author(s):  
Gonzalo Álvarez ◽  
Patricio Díaz ◽  
Marcos Godoy ◽  
Michael Araya ◽  
Iranzu Ganuza ◽  
...  
Keyword(s):  
Digestive Gland ◽  
Harmful Algal Bloom ◽  
Geographical Area ◽  
Monitoring Program ◽  
Adductor Muscle ◽  
Shellfish Poisoning ◽  
Alexandrium Catenella ◽  
Surf Clam ◽  
Paralytic Shellfish ◽  
Psp Toxins

In late February 2016, a harmful algal bloom (HAB) of Alexandrium catenella was detected in southern Chiloé, leading to the banning of shellfish harvesting in an extended geographical area (~500 km). On April 24, 2016, this bloom produced a massive beaching (an accumulation on the beach surface of dead or impaired organisms which were drifted ashore) of surf clams Mesodesma donacium in Cucao Bay, Chiloé. To determine the effect of paralytic shellfish poisoning (PSP) toxins in M. donacium, samples were taken from Cucao during the third massive beaching detected on May 3, 2016. Whole tissue toxicity evidence a high interindividual variability with values which ranged from 1008 to 8763 μg STX eq 100 g−1 and with a toxin profile dominated by GTX3, GTX1, GTX2, GTX4, and neoSTX. Individuals were dissected into digestive gland (DG), foot (FT), adductor muscle (MU), and other body fractions (OBF), and histopathological and toxin analyses were carried out on the obtained fractions. Some pathological conditions were observed in gill and digestive gland of 40–50% of the individuals that correspond to hemocyte aggregation and haemocytic infiltration, respectively. The most toxic tissue was DG (2221 μg STX eq 100 g−1), followed by OBF (710 μg STX eq 100 g−1), FT (297 μg STX eq 100 g−1), and MU (314 μg STX eq 100 g−1). The observed surf clam mortality seems to have been mainly due to the desiccation caused by the incapability of the clams to burrow. Considering the available information of the monitoring program and taking into account that this episode was the first detected along the open coast of the Pacific Ocean in southern Chiloé, it is very likely that the M. donacium population from Cucao Bay has not had a recurrent exposition to A. catenella and, consequently, that it has not been subjected to high selective pressure for PSP resistance. However, more research is needed to determine the effects of PSP toxins on behavioral and physiological responses, nerve sensitivity, and genetic/molecular basis for the resistance or sensitivity of M. donacium.

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