scholarly journals Fate of glair glands and spawning behaviour in unmated crayfish: a comparison between gonochoristic slough crayfish and parthenogenetic marbled crayfish

2016 ◽  
Author(s):  
Günter Vogt
Keyword(s):  
Late Summer ◽  
Late Winter ◽  
Freshwater Crayfish ◽  
Procambarus Fallax ◽  
In Captivity ◽  
Genetic Mechanisms ◽  
Spawning Behaviour ◽  
Long Term Observation ◽  
Marbled Crayfish

AbstractIn the period before spawning, freshwater crayfish females develop glair glands on the underside of the pleon. These glands produce the mucus for a transient tent-like structure in which the eggs are fertilized and attached to the pleopods. Long-term observation of females of the bisexually reproducing slough crayfish, Procambarus fallax, kept in captivity revealed that glair glands developed in late winter and late summer of each year independent of the presence of males. However, in contrast to mated females unmated females did neither form a fertilization tent nor spawn. Their glair glands persisted for an unusually long period of time and disappeared only during the next moult. Apparently, females use information on sperm availability to either reproduce or save the resources. Marbled crayfish, Procambarus virginalis, a parthenogenetic descendant of slough crayfish, developed glair glands in approximately the same periods of the year but spawned despite of the absence of mating. These findings indicate that on their way from gonochorism to parthenogenesis regulation of glair gland activity and spawning has been decoupled from mating. Therefore, the species pair Procambarus fallax/Procambarus virginalis seems to be particularly suitable to investigate the physiological, molecular and genetic mechanisms underlying spawning in freshwater crayfish.

Impact of Low-Molecule Acidic Peptides on Growth and Histological Structure of Inner Organs of Marbled Crayfish Procambarus fallax (Hagen, 1870) F. virginalis

2016 ◽  
Vol 56 ◽  
pp. 1-6
Author(s):  
Oleh Marenkov ◽  
Elena Fedonenko ◽  
Alexandra Naboka
Keyword(s):  
Acidic Solution ◽  
Histological Structure ◽  
Low Molecular Weight ◽  
Freshwater Crayfish ◽  
Fat Cells ◽  
Procambarus Fallax ◽  
Inner Organs ◽  
Marbled Crayfish ◽  
The Impact ◽  
Acidic Peptides

The results of studies on the effects of low molecular weight acidic solution peptides on the growth and development of the marbled crayfish artificial cultivation.An increasing weights of juvenile freshwater crayfish under the influence of dietary supplement "Albuvir" drug. With the use of histological methods of research, found the impact of 0.01% solution of the drug on the state of the marbled crayfish lobules of hepatopancreas and fat cells. Developed a method for growing juvenile freshwater crayfish with "Albuvir", which allows to increase the weight gain of crustaceans on 24.3–27.2% and reduce the level of cannibalism at 20%.

scholarly journals Half a century of monitoring macrobenthic animals on tidal flats in the Dutch Wadden Sea

2020 ◽  
Vol 656 ◽  
pp. 1-18
Author(s):  
JJ Beukema ◽  
R Dekker
Keyword(s):  
Tidal Flat ◽  
Wadden Sea ◽  
Late Summer ◽  
Late Winter ◽  
Minor Role ◽  
Data Series ◽  
Shore Crabs ◽  
A Minor ◽  
Rates Of Growth

Macrobenthic animals living in a tidal-flat area in the westernmost part of the Wadden Sea were monitored for 50 yr (1970-2019) using consistent methods. About 100 papers were published on this project. We review a number of results and conclusions on observed changes and their possible underlying causal processes. The most significant changes in population sizes and growth rates of several species could be attributed to climate warming (by about 2°C), along with increasing trends in species richness and total late-winter zoobenthic biomass. In the initial years, eutrophication (doubling of nutrients and chlorophyll concentrations) resulted in a doubling of zoobenthic biomass. The subsequent de-eutrophication after the mid-1980s was reflected only in the biomass values observed in late summer. A long-term trend in food supply for birds was not observed. Disturbances from fisheries were intermittent and modest. In several bivalve species, magnitudes of production and biomass were determined primarily by recruitment variation, which was mainly caused by spring abundance of epibenthic predators (shore crabs and shrimps). Their abundance increased with temperatures in the preceding winter. In contrast to this top-down regulation, bottom-up processes apparently played only a minor role in the determination of bivalve biomass. Rarely occurring extremely high bivalve numbers resulted in reduced rates of growth and production. We conclude that the uniquely long monitoring of the tidal-flat macrozoobenthos yielded data series which not only indicated several long-term trends, but also contributed to our insight in processes underlying the observed trends. Most of the observed trends were related to climate change and eutrophication followed by de-eutrophication.

scholarly journals Phylogeographic reconstruction of the marbled crayfish origin

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Julian Gutekunst ◽  
Olena Maiakovska ◽  
Katharina Hanna ◽  
Panagiotis Provataris ◽  
Hannes Horn ◽  
...  
Keyword(s):  
Geographic Origin ◽  
Freshwater Crayfish ◽  
Parent Species ◽  
Parent Population ◽  
Diploid Parent ◽  
Phylogeographic Analysis ◽  
Procambarus Fallax ◽  
Important Intermediate ◽  
Crayfish Population ◽  
Marbled Crayfish

AbstractThe marbled crayfish (Procambarus virginalis) is a triploid and parthenogenetic freshwater crayfish species that has colonized diverse habitats around the world. Previous studies suggested that the clonal marbled crayfish population descended as recently as 25 years ago from a single specimen of P. fallax, the sexually reproducing parent species. However, the genetic, phylogeographic, and mechanistic origins of the species have remained enigmatic. We have now constructed a new genome assembly for P. virginalis to support a detailed phylogeographic analysis of the diploid parent species, Procambarus fallax. Our results strongly suggest that both parental haplotypes of P. virginalis were inherited from the Everglades subpopulation of P. fallax. Comprehensive whole-genome sequencing also detected triploid specimens in the same subpopulation, which either represent evolutionarily important intermediate genotypes or independent parthenogenetic lineages arising among the sexual parent population. Our findings thus clarify the geographic origin of the marbled crayfish and identify potential mechanisms of parthenogenetic speciation.

scholarly journals Diel, seasonal, and interannual patterns in mesozooplankton abundance in the Sargasso Sea

2018 ◽  
Vol 76 (1) ◽  
pp. 217-231 ◽  
Author(s):  
Jami A Ivory ◽  
Deborah K Steinberg ◽  
Robert J Latour
Keyword(s):  
Time Series ◽  
Linear Models ◽  
Imaging System ◽  
Environmental Parameters ◽  
Late Summer ◽  
Late Winter ◽  
Sargasso Sea ◽  
Calanoid Copepods ◽  
Decadal Scale

Abstract Temporal changes in mesozooplankton abundance affect planktonic food web interactions and biogeochemistry. We enumerated mesozooplankton from monthly day and night tows in the epipelagic zone at the Bermuda Atlantic Time-series Study (BATS) site in the Sargasso Sea (1999–2010). Abundances of each taxon were determined using a ZooScan imaging system and microscopy. Generalized linear models were used to determine environmental parameters that best explained abundance patterns. Taxa with pronounced diel vertical migration included euphausiids, amphipods, Limacina spp. pteropods, and other shelled pteropods. Taxa with a pronounced spring abundance peak included euphausiids, appendicularians, and Limacina spp., while harpacticoid copepods peaked in late summer, and calanoid copepods in late winter/early spring and summer. Many taxa increased in 2003, coincident with a diatom bloom and the largest primary production peak in the time series. Long-term, increasing trends occurred in calanoid and oncaeid copepods, and ostracods, with barnacle nauplii significantly increasing. Sub-decadal-scale climate oscillations and long-term warming may be driving decreases in shelled pteropods and appendicularians. Chaetognath abundance increased in response to increased density of a major prey taxon, calanoid copepods. Calanoid copepods and ostracods increased with increasing water column stratification index and the Atlantic Multidecadal Oscillation index, indicating warmer sea surface temperatures favour these taxa.

Features of histological adaptation of Marbled crayfish Procambarus fallax f. virginalis (Decapoda) to the different concentration of cadmium ions in model experiment

2017 ◽  
Vol 28 (3-4) ◽  
pp. 37-44
Author(s):  
O. N. Marenkov ◽  
K. K. Holoborodko ◽  
Yu. S. Voronkova ◽  
V. A. Gorban
Keyword(s):  
Excretory System ◽  
Histological Structure ◽  
Freshwater Crayfish ◽  
Cadmium Ions ◽  
Gland Cells ◽  
Procambarus Fallax ◽  
Antennal Gland ◽  
Glandular Cells ◽  
Mechanisms Of Adaptation ◽  
Marbled Crayfish

The article shows the results of studies on the influence of cadmium ions on the histological structure of antennal gland cells of marbled crayfish Procambarus fallax f. virginalis Martin et al., 2010 (Decapoda). Due to the fact that marbled crayfish got into the reservoirs of the Dnipropetrovsk region in 2015, it was necessary to study the possibilities of its adaptation to environmental factors of reservoirs for further prediction of its distribution or even acclimatization under conditions of toxicological contamination of the ponds of the steppe Prydniprovya. We conducted a laboratory model experiments to study the mechanisms of adaptation of marbled crayfish Procambarus fallax f. virginalis. The effect of different concentrations of cadmium ions (0.01 mg/l, 2 MРC) on physiological state and histostructure of the excretory system of marbled crayfish was determined. The cells of the antennal gland of marbled crayfish in the control had a size of 166.08 ± 10.13 μm2. Glandulocytes had clear cells edges, pronounced structure of ducts, and a clear basal membrane. The cells had large nuclei with a cross-sectional area of 51.31±3.92 μm2. The nucleic membrane had clear edges, there were nucleoli in nuclei that were characterized by basophilia. That is, the structure of the antennal gland of marbled crayfish in control was normal for Decapods. The worst histological picture of antennal gland cells was observed in individuals exposed to cadmium ions. The structure of the excretory ducts of the green gland was broken, they had fuzzy boundaries, contained a large number of fragments of glandulocytes cytoplasm. In some cells there was a picnose of nuclei, as well as the output of a nucleolus beyond the nucleus which is the appearance of the micronucleus. This phenomenon is caused by the toxicological effects of cadmium. Compared with control, the glandulocytes of the antennal gland were 14.8 % smaller, their area of cross-section reached 141.44±7.60 μm2. The nuclei of the glandular cells were also significantly lower by 17.5 % than such in control, and their area reached 42.32±1.74 μm2. To study the influence of cadmium on the glandular cells of the green gland of marbled crayfish, the index of nuclear-cytoplasmic ratio (NCR) was used. The indicator of nuclear-cytoplasmic ratio allows estimating the level of metabolism and detecting the manifestation of compensatory reactions of the organism of experimental crayfish. The value of NCR in the trial and control did not differ statistically and amounted to 0.31 units. This indicates an interproportional reduction in both the cytoplasm of the cells of the green gland and their nuclei, caused by cadmium exposure. It was determined that under the influence of heavy metals the size of the glandular cells and their nuclei decreases, while the nuclear-cytoplasmic ratio remains the same, which is probably an adaptive reaction of the excretory system against the influence of heavy metal ions. Investigation of the histological structure of tissues and organs of marbled crayfish will allow the development of measures for the determination of biomarkers for the bioindication of the aquatic environment using freshwater crayfish. The results of such studies have an important fundamental and applied significance for understanding the mechanisms of adaptation of crustaceans to the conditions of toxicological burden on aquatic ecosystems.

scholarly journals Annual variation and global distribution of strato-mesospheric carbon monoxide measured by ground-based Fourier Transform Infrared spectrometry

2006 ◽  
Vol 6 (4) ◽  
pp. 7119-7135 ◽  
Author(s):  
V. Velazco ◽  
S. W. Wood ◽  
M. Sinnhuber ◽  
I. Kramer ◽  
N. B. Jones ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Transport Model ◽  
Late Summer ◽  
The Arctic ◽  
Infrared Spectrometry ◽  
Late Winter ◽  
Chemistry Transport Model ◽  
Annual Variability ◽  
Summer Maximum

Abstract. We present long-term time-series of strato-mesospheric CO vertical columns measured from stations located in Antarctica, mid-latitudes and the Arctic, covering the period from 1997–2005. The instrument and the measurement technique allows the separation of tropospheric and strato-mesospheric contributions to the CO column, therefore providing information on the chemistry and dynamics both at low and high altitudes. Data from polar stations show a similar annual variability of strato-mesospheric CO with a strong maximum in late winter and spring and a small enhancement in late summer for some stations, which we call the "summer bulge''. Generally, the mid-latitude stations show no significant annual variability of strato-mesospheric CO columns. Measurements were compared with a two-dimensional chemistry-transport model of the middle atmosphere. The annual and latitudinal variations of CO are reproduced very well by a model run including thermospheric CO. Comparison with different model scenarios show that the polar winter maximum is due solely to downward transport of thermospheric CO, while the summer maximum is due to CHOx chemistry in the stratosphere.

scholarly journals Annual variation of strato-mesospheric carbon monoxide measured by ground-based Fourier transform infrared spectrometry

2007 ◽  
Vol 7 (5) ◽  
pp. 1305-1312 ◽  
Author(s):  
V. Velazco ◽  
S. W. Wood ◽  
M. Sinnhuber ◽  
I. Kramer ◽  
N. B. Jones ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Transport Model ◽  
Late Summer ◽  
The Arctic ◽  
Infrared Spectrometry ◽  
Late Winter ◽  
Chemistry Transport Model ◽  
Annual Variability ◽  
Summer Maximum

Abstract. We present long-term time-series of strato-mesospheric CO vertical columns measured from stations located in Antarctica, mid-latitudes and the Arctic, covering the period from 1997–2005. The instrument and the measurement technique allows the separation of tropospheric and strato-mesospheric contributions to the CO column, therefore providing information on the chemistry and dynamics both at low and high altitudes. Data from polar stations show a similar annual variability of strato-mesospheric CO with a strong maximum in late winter and spring. A small enhancement in late summer for some stations, which we call the "summer bulge", can be seen occasionally. Generally, the mid-latitude stations show no significant annual variability of strato-mesospheric CO columns. Measurements were compared with a two-dimensional chemistry-transport model of the middle atmosphere. The annual and latitudinal variations of CO are reproduced well by a model run including thermospheric CO. Comparison with two model scenarios show that the polar winter maximum is due solely to downward transport of thermospheric CO, while CHOx chemistry in the stratosphere could probably contribute to the summer maximum.

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