Search results for " mussel"

Electrofishing as a new method to search for unknown populations of the endangered freshwater pearl mussel Margaritifera margaritifera

2017

1. The freshwater pearl mussel Margaritifera margaritifera is threatened throughout its Holarctic range, but the occurrence of this species is insufficiently mapped. For the conservation of M. margaritifera, it is important to identify populations more comprehensively. 2. Traditionally mussels have been searched for visually using techniques such as diving and aquascope, both of which are potentially time-consuming and demanding survey methods. 3. In this study, a new search method is presented. As glochidia of M. margaritifera are larval parasites on gills of salmonid fish, electrofishing and non-destructive examination of salmonids with the naked eye may reveal the presence of glochidia a…

Immunization of trout (Salmo trutta) against freshwater pearl mussel (Margaritifera margaritifera) by duck mussel (Anodonta anatina) glochidia

2013

Freshwater pearl mussel Margaritifera margaritifera is endangered throughout its range of distribution in Europe. In some rivers M. margaritifera may co-occur with the duck mussel Anodonta anatina. Brown trout Salmo trutta serves as suitable fish host for both mussel species. Thus it is possible that exposure of brown trout to A. anatina glochidia might increase resistance of fish against M. margaritifera glochidia. The aim was to test this ‘cross immunity hypothesis’. Brown trout were immunized by duck mussel (Anodonta anatina) glochidia in late May. Then brown trout were challenged by pearl mussel (Margaritifera margaritifera) glochidia in late August after the A. anatina glochidia were d…

Hemocytes and humoral defense factors variability from different Mediterranean populations of Mytilus galloprovincialis

2010

Interactions between two parasites of brown trout (Salmo trutta): Consequences of preinfection

2018

Preinfection by one parasitic species may facilitate or by contrast hamper the subsequent penetration and/or establishment of other parasites in a host. The biology of interacting species, timing of preinfection, and dosage of subsequent parasite exposure are likely important variables in this multiparasite dynamic infection process. The increased vulnerability to subsequent infection can be an important and often overlooked factor influencing parasite virulence. We investigated how the preinfection by freshwater pearl mussel Margaritifera margaritifera glochidia could influence the success of subsequent infection by the common trematode Diplostomum pseudospathaceum in brown trout Salmo tru…

Glochidia Infection of Endemic Fishes from Lake Prespa, N. Macedonia

2022

Large freshwater mussels (Unionida) are long-lived, have large bodies, and produce thousands to millions of larvae (glochidia) that usually must attach to host fish tissue to complete their life cycle. This is an obligate parasitic stage of mussel larvae. However, less than one in onemillion find a suitable host and survive. The degree of host specificity varies among unionid species, from specialists that can successfully parasitize only one or a few closely related fish species to generalists that can complete development on a taxonomically broad range of fish species. In addition, freshwater mussels are among the most threatened groups of animals. This is due to habitat destruction, the …

Effect of low dissolved oxygen on the viability of juvenile Margaritifera margaritifera : Hypoxia tolerance ex situ

2022

The decline of endangered freshwater pearl mussel (FPM, Margaritifera margaritifera) has been attributed to juvenile mortality caused by low concentrations of dissolved oxygen in the stream substrate resulting from fine sediments (siltation) that impede water exchange in the interstitial microhabitat of juveniles. If low oxygen concentration causes recruitment failure of FPMs, knowledge on the oxygen tolerance of juvenile FPMs is essential for the conservation of the species, as it will justify conservation efforts improving water exchange in the bottom gravel. However, the tolerance of low oxygen of FPM juveniles has not been directly studied. Juvenile FPMs (9–11 months old) were exposed i…

L’effetto della mitilicoltura posta a valle di allevamenti di specie ittiche riduce il carico organico

2007

L’utilizzo del mussel cleaning che sfrutta le caratteristiche fisiologiche dei molluschi filtratori per la mitigazione degli impatti derivanti da reflui particellati di origine antropica, ed in particolare delle attività di piscicoltura, è stato introdotto di recente in diversi paesi europei. Tale procedura si basa sull’ipotesi che la filtrazione operata da elevate biomasse di molluschi eduli posti nei pressi degli impianti di pescicoltura possa ridurre il carico organico in eccesso proveniente dal surplus di mangime fornito ai pesci allevati e che in certa parte inutilizzato tende a sedimentare al di sotto delle gabbie di allevamento. In questo studio abbiamo analizzato in due periodi diff…

Pulsed flow-through cultivation of Margaritifera margaritifera : effects of water source and food quantity on the survival and growth of juveniles

2020

AbstractConservation of the endangered freshwater pearl mussel (FPM) includes artificially rearing juveniles, but the pulsed flow-through (PFT) method, enabling the continuous renewal of water and food in culture containers, has not been applied to FPM. This study tested the PFT method in culture of FPM juveniles, and the effect of water source (tap vs well water) and food concentration (mixture of commercial phytoplankton products) on the survival and growth of juveniles. Beaker-specific survival rates varied from 0 to 100% (mean: 34%) and from 0 to 58% (mean: 16%) in the 1st (2-week) and 2nd (10-week) experiment, respectively. In the 1st experiment, juveniles attained statistically signif…