Search results for "Decapoda"
showing 4 items of 54 documents
Comparative ultrastructure and carbohydrate composition of gastroliths from Astacidae, Cambaridae and Parastacidae freshwater crayfish (Crustacea, De…
2012
21 pages; International audience; Crustaceans have to cyclically replace their rigid exoskeleton in order to grow. Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish) elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohy…
Unusual oxygen binding behavior of a 24-meric crustacean hemocyanin.
2009
Abstract Hemocyanins from Crustacea usually are found as 1 × 6 or 2 × 6-meric assemblies. An exception is the hemocyanin isolated from thalassinidean shrimps where the main component is a 24-meric structure. Our analysis of oxygen binding data of the thalassinidean shrimp Upogebia pusilla based on a three-state MWC-model revealed that despite the 24-meric structure the functional properties can be described very well based on the hexamer as allosteric unit. In contrast to the hemocyanins from other thalassinidean shrimps the oxygen affinity of hemocyanin from U. pusilla is increased upon addition of l -lactate. A particular feature of this hemocyanin seems to be that l -lactate already enha…
Nikkelin kertyminen täplärapuun (Pacifastacus leniusculus) kahdessa eri lämpötilassa
2017
Kaivostoiminnan aiheuttamat metallipäästöt ovat maailmanlaajuinen ympäristöongelma. Kaivospäästöjen takia metalleja pääsee luontoon ja eliöstöön biosaatavassa vesiliukoisessa muodossa kuten sulfaatteina tai klorideina. Nikkeli on bioakkumuloituva eliöille haitallinen metalli, jota käytetään teollisuuden raaka-aineena ympäri maailmaa. Tässä tutkielmassa tarkasteltiin nikkelin kertymistä täplärapuun (Pacifastacus leniusculus) laboratorio-olosuhteissa kahdella 14 vrk:n altistuskokeella eri nikkelialtistuspitoisuuksilla kahdessa eri lämpötilassa (7 ja 17 °C). Eri testilämpötiloilla pyrittiin selvittämään, onko nikkelin kertyminen riippuvaista vaihtolämpöisen täpläravun aineenvaihduntatasosta. K…
Environmental features of deep-sea habitats linked to the genetic population structure of a crustacean species in the Mediterranean Sea
2009
The deep-sea habitat, from 200 to 2000 m depth, has long been thought as an ecosystem where biotic and abiotic factors vary very little and consequently species are not disturbed by processes and phenomena which could promote fast evolutionary mechanisms. Unfortunately, biological information relating to deep water is limited, especially regarding the population genetics of species inhabiting the Mediterranean Sea, and general patterns cannot be inferred. In this study we report data on the population genetic structure of Aristeus antennatus, a deep-sea decapod crustacean species which has been widely studied due to its important economic value. We surveyed and examined the variation in a 3…