scholarly journals Tube-building in two epifaunal amphipod species,Corophium insidiosum andJassa falcata

1995 ◽  
Vol 49 (1-4) ◽  
pp. 393-398 ◽  
Author(s):  
I. Ulrich ◽  
K. Anger ◽  
U. Schöttler
Author(s):  
PA Peres ◽  
AP Ferreira ◽  
GBO Machado ◽  
M Azevedo-Silva ◽  
SGL Siqueira ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Jakob ◽  
Kseniya P. Vereshchagina ◽  
Anette Tillmann ◽  
Lorena Rivarola-Duarte ◽  
Denis V. Axenov-Gribanov ◽  
...  

AbstractLake Baikal is inhabited by more than 300 endemic amphipod species, which are narrowly adapted to certain thermal niches due to the high interspecific competition. In contrast, the surrounding freshwater fauna is commonly represented by species with large-scale distribution and high phenotypic thermal plasticity. Here, we investigated the thermal plasticity of the energy metabolism in two closely-related endemic amphipod species from Lake Baikal (Eulimnogammarus verrucosus; stenothermal and Eulimnogammarus cyaneus; eurythermal) and the ubiquitous Holarctic amphipod Gammarus lacustris (eurythermal) by exposure to a summer warming scenario (6–23.6 °C; 0.8 °C d−1). In concert with routine metabolic rates, activities of key metabolic enzymes increased strongly with temperature up to 15 °C in E. verrucosus, whereupon they leveled off (except for lactate dehydrogenase). In contrast, exponential increases were seen in E. cyaneus and G. lacustris throughout the thermal trial (Q10-values: 1.6–3.7). Cytochrome-c-oxidase, lactate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase activities were found to be higher in G. lacustris than in E. cyaneus, especially at the highest experimental temperature (23.6 °C). Decreasing gene expression levels revealed some thermal compensation in E. cyaneus but not in G. lacustris. In all species, shifts in enzyme activities favored glycolytic energy generation in the warmth. The congruent temperature-dependencies of enzyme activities and routine metabolism in E. verrucosus indicate a strong feedback-regulation of enzymatic activities by whole organism responses. The species-specific thermal reaction norms reflect the different ecological niches, including the spatial distribution, distinct thermal behavior such as temperature-dependent migration, movement activity, and mating season.


2021 ◽  
Author(s):  
Polina Lipaeva ◽  
Kseniya Vereshchagina ◽  
Polina Drozdova ◽  
Lena Jakob ◽  
Elizaveta Kondrateva ◽  
...  

Crustaceana ◽  
1997 ◽  
Vol 70 (6) ◽  
pp. 676-693
Author(s):  
Thomas Bolger ◽  
Rory P. O'Hanlon

AbstractAnthropogenic dispersal has led to the introduction of several terrestrial amphipod species to the northern hemisphere. One such species, Arcitalitrus dorrieni (Hunt, 1925), a native of Australasia, is now found in several woodland sites in Ireland and Britain. Aspects of the biology of A. dorrieni were investigated in County Galway over a period of two years and compared between a "typical" mixed deciduous woodland habitat and a more "atypical" coniferous woodland habitat. At both sites, statistically significant differences were found between summer (Aug.-Sep.) size at maturity and winter (Jan.-Apr.) size at maturity, i.e., females were mature at smaller sizes in summer than in winter. Between-site comparisons of August-September data for both years showed that females were mature at a significantly smaller size at the mixed deciduous woodland site. A sex ratio biased in favour of females was recorded on all but one sampling date at each site, though on some dates this bias was not significant. The change in cohort sex ratio at both sites was quite distinct and exhibited the same general pattern. During the recruitment of each cohort, the ratio was biased towards males. As the cohort increased in length, however, the ratio changed to a bias in favour of females, so that by the time a particular cohort entered its breeding period the following year, it was biased firmly in favour of females. Possible reasons for the observed patterns are discussed.


2019 ◽  
Vol 170 ◽  
pp. 168-177 ◽  
Author(s):  
Ana Rita Lopes ◽  
Francisco Oliveira Borges ◽  
Cátia Figueiredo ◽  
Eduardo Sampaio ◽  
Mário Diniz ◽  
...  

2011 ◽  
Vol 83 (3) ◽  
pp. 1031-1040 ◽  
Author(s):  
André R. Senna

A new amphipod species of the genus Elasmopus Costa, 1853 is described based on material collected from intertidal rocky shore, near the Suape Harbor, coast of the Brazilian state of Pernambuco. The new species may be recognized by the propodus of gnathopod 2 suboval, slightly tapering distally, palmar margin not defined by a stout seta, spine, or palmar corner, with a subdistal blunt tubercle, posterior margin covered by a dense fringe of plumose setae, and posterior margin of basis of pereopod 7 castelloserrate. This is the ninety-fifth species of the genus Elasmopus described worldwide, the most diverse genus in the family Maeridae Krapp-Schickel, 2008, and the eighth species recorded from Brazilian waters. An identification key to Brazilian species of Elasmopusis also provided.


Hydrobiologia ◽  
2015 ◽  
Vol 761 (1) ◽  
pp. 143-159 ◽  
Author(s):  
Stefano Schiaparelli ◽  
Maria Chiara Alvaro ◽  
Niamh Kilgallen ◽  
Alice Scinto ◽  
Anne-Nina Lörz
Keyword(s):  
Ross Sea ◽  

Author(s):  
P.G. Moore ◽  
P.S. Rainbow

Ferritin crystals and calcium granules are reported from the ventral ceaca of Steleuthera ecoprophycea (Amphipoda: Stegocephalidae) collected from the Snake Pit hydrothermal vent, Mid-Atlantic Ridge (3520 m).In a series of earlier papers (Moore & Rainbow, 1984, 1989, 1992; Moore et al., 1994), the authors described the widespread occurrence of intracellular, octahedral crystals of ferritin in the ventral caeca of a range of stegocephalid amphipod species from the continental shelf epibenthos and oceanic plankton. The discovery at 3500 m of a new Steleuthera species (S. ecoprophycea), from a hydrothermal vent on the Mid-Atlantic Ridge was announced recently by Bellan-Santini & Thurston (1996), and a complete description is provided therein.Oceanic ridge sites are notable for their tectonic activity and the presence of a diversity of trace metals at high concentrations is to be expected in hydrothermal plumes emanating from such regions (German & Angel, 1995). The detoxification of accumulated trace metals in the ventral ceaca of stegocephalid amphipods from uncontaminated environments is now relatively well known (see above), so it was of interest to investigate whether a vent stegocephalid showed an atypical presence of trace metals in detoxified form in cells of the ventral caeca. The results following from an opportunity to investigate this are reported herein.Material was derived from a dive made by the submersible ‘Alvin’ at Snake Pit hydrothermal field, Mid-Atlantic Ridge (23°23′N 44°56′W), 3520 m, on 16 June 1993 (see Bellan-Santini & Thurston, 1996). Steleuthera ecoprophycea was preserved in 70% alcohol. Subsequently to dissection, the single pair of ventral caeca from each of the four damaged amphipods investigated were post-fixed in 4% glutaraldehyde. For electron microscopy and x-ray microanalysis in STEM mode, ventral caecal tissues were then dehydrated through 95% and absolute ethanol, cleared in propylene oxide, embedded in TAAB resin, sectioned at 0·5 μm (semi-thin sections) on a Reichert OmU2 ultramicrotome and examined without staining in a JEOL 100C electron microscope equipped with LINK system EDX energy dispersive x-ray microanalyser.


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