Search results for "Crustacea"

Variations in haemolymph ionized calcium concentrations in the crustacean Orchestia cavimana during a moult cycle

1993

Abstract Measurements of ionized calcium concentration in the haemolymph of the semi-terrestrial crustacean Orchestia cavimana were taken during the 14 successive moulting stages by ion-selective electrode direct potentiometry on pooled samples. Ionized calcium showed major variations associated with the moult cycle. Titres were low and relatively stable in intermoult and early premoult, then progressively increased during mid and late premoult to reach maximal values just at exuviation, and rapidly fell down during the postmoult. The variations of the ionized fraction showed a close correlation with those of the calcaemia (= total fraction), suggesting the presence of efficient haemolympha…

Helminth infestation of three fishes (Serranus scriba, Mullus surmuletus, Scorpaena porcus)from a coastal seaground in the Gulf of Palermo (Tyrrhenia…

1997

Abstract The results of a year's survey on the parasitic infestation of the gastrointestinal tract of three species of benthic fish, namely Serranus scriba, Mullus surmuletus, and Scorpaena porcus, living in a restricted coastal seaground in the N/W sector of the Gulf of Palermo, are reported and critically discussed. Fish populations were sampled monthly by means of a trammel net, according to the local fishing usage. As many as nine helminth species, five of them trematodes and four nematodes, were collected from the gastrointestinal tract of 625 individuals. Infestation was most intense in M. surmuletus, with a peak in the spring. S. scriba was especially parasitized during the spring an…

The nucleic acid binding protein PcCNBP is transcriptionally regulated during the immune response in red swamp crayfish Procambarus clarkii

2015

Cellular nucleic acid binding proteins (CNBPs) represent a highly conserved protein family among vertebrates; they harbour seven tandem zinc finger repeats CCHC type and have been described as transcriptional and translational regulators. To date, there is little characterization of CNBP in invertebrates since its structure and function have been analysed solely in Drosophila melanogaster. However, no CNBP has been investigated in other arthropod systems. In an effort to isolate immune-related genes in Procambarus clarkii, a partial mRNA coding a zinc finger containing protein was found to be up-regulated during the response to white spot syndrome virus (WSSV) infection. The red swamp crayf…

The structure of parasite component communities in brackish water fishes of the northeastern Baltic Sea

2001

We used nestedness analysis to seek non-random patterns in the structure of component communities of metazoan parasites collected from 31 sympatric fish species from the northeastern Bothnian Bay, the most oligohaline area of the Baltic Sea. Only 8 marine parasite species were found among the 63 species recorded, although some marine fish species reproduce in the bay and others occasionally visit the area. Marine parasite species can utilize both freshwater and marine fish species as intermediate or final hosts, and marine fish can harbour freshwater parasite species. This exchange of parasite species between marine and freshwater fish has probably resulted from ecological factors acting ov…

Ostracods of Mediterranean temporary inland waters (Greece, Southern Italy, and Malta)

2015

A survey of ovarian maturation in a population of Aristeus antennatus [Crustacea: Decapoda)

1995

Host searching in Argulus foliaceus L. (Crustacea: Branchiura): the role of vision and selectivity.

1998

In laboratory experiments, the swimming behaviour of the ectoparasite Argulus foliaceus and its infection rates on juvenile perch (Perca fluviatilis) and roach (Rutilus rutilus) were examined. The highest infection rate and a preference for perch juveniles were obtained in darkness, the lowest infection rate and a lack of preference in the light, when aquaria with glass walls (high reflectivity) were used. In the light, when aquaria were lined with black plastic (low reflectivity) an intermediate level of infection for perch and the highest for roach was recorded. Under such conditions roach were significantly more heavily infected than perch; an attack rate 4 times greater was recorded for…

Cadmium induced metallothionein in hepatopancreas of Procambarus clarkii: Quantification by a silver-saturation method

1993

Abstract 1. Cadmium induced metallothionein (MT) in crayfish hepatopancreas was measured by silver-saturation method. 2. An increase in MT content was recorded in crayfish hepatopancreas after 12 hr of exposure to 10 mg Cd/l. 3. There was found to be a linear relationship between MT concentrations in hepatopancreas and cadmium concentration in the water. 4. MT levels in hepatopancreas of 20 mg Cd/l exposed crayfish were 7-fold higher than those in control animals.

The effect of time, concentration and temperature on bioaccumulation in the gill of crayfish procambarus clarkii induced by organochlorine pesticides…

1993

Abstract 1. Crayfish were exposed to 1 25 th 96-hr lc 50 and 96-hr lc 50 of lindane and endosulfan for 1, 24, 48, 72 and 96 hr. 2. Concentrations of lindane and endosulfan were determined in gill tissue at 22°C and 29°C. 3. Clear differences were found in all concentrations, times and temperatures tested in gill tissues. 4. The highest accumulation of pesticide was found in the lc 50 endosulfan value.

Fine structure of sensilla during moulting inNeomysis integer (Leach) (Crustacea, Mysidacea)

1980

During the moulting cycle the sensory cells and the newly formed hair shaft remain connected to the old cuticular receptive apparatus of the sensillum by the elongated outer segments of the dendrites, which run through the exuvial space. A surface coat covering the outer dendritic segments protects them against the chemical influences of the exuvial fluid. The findings suggest that the receptors remain functional until ecdysis. This moulting type is considered to be a transitional form between the moulting types so far known.