Daily activity rhythms and the stress-related response in the wedge sole (Dicologoglossa cuneata Moreau, 1881).

To gain further insights on the wedge sole (Dicologoglossa cuneata Moreau, 1881) physiology and behavior, we evaluated its daily feeding and locomotor activity rhythms and compared three different feeding strategies: self-feeding (SF), diurnal feeding schedule (DS) and nocturnal feeding schedule (NS). 450 fish divided into three groups (three replicates each), were kept during 65days. SF had free access to self-feeders whereas DS and NS were fed four times a day. Physiological stress parameters as plasma cortisol, glucose, lactate, proteins and triglycerides were determined. Under the SF setting, the 91% of feeding demands occurred during the dark phase. Furthermore, locomotor activity was also higher during the scotophase (64% of the total activity). Significantly higher values for specific growth rate (SGR) and feed efficiency rate (FER) were observed in NS (0.49 and 0.48%day-1, respectively); whereas SF consumed much less food than the rest and presented a high mortality rate (46%). Plasma cortisol levels were dramatically increased in SF and DS compared to NS (21.8±6.1, 65.8±30.3 and 0.3±0.1ngmL-1, respectively). In summary, the wedge sole appears as a species with nocturnal locomotor and feeding behaviors and NS as the most appropriate feeding strategy. These new findings appear as key information for both the preservation of natural stocks of this species and its rearing.

Characterization of Vibrio tapetis strains isolated from diseased cultured Wedge sole (Dicologoglossa cuneata Moreau).

The first isolation of Vibrio tapetis from Wedge sole (Dicologoglossa cuneata) is reported. The bacterium was recovered from ulcers of ailing cultured fish, from two different outbreaks occurred in spring 2005. The four isolates found (a200, a201, a204 and a255) were biochemically, genetically and serologically characterized and diagnosis was confirmed by PCR V. tapetis specific primers and multilocus sequencing analysis (MLSA). The isolates constituted a homogeneous phenotypic and genotypic group, being distinct to the already serological and genetic groups defined within the species. A virulence evaluation of the isolate a255 was also carried out; however this strain was unable to induce disease in fry and juvenile Wedge sole.

Comparison of Application Methods of Systemic Fungicides to Suppress Branch Cankers in Clementine Trees Caused by Phytophthora citrophthora.

Since 2002, considerable losses of Clementine trees (Citrus clementina) have been observed in Spain due to Phytophthora branch canker of citrus caused by Phytophthora citrophthora. Due to the low efficiency of the available cultural and genetic control measures, application of fungicides is required for economic management of the disease. Fosetyl-Al, metalaxyl, and its enantiomer mefenoxam are the only systemic fungicides registered for control of Phytophthora diseases in Spain. However, their efficacy has not been tested against Phytophthora branch canker. Greenhouse and field experiments were conducted for 3 years in Spain to evaluate the ability of these fungicides and application methods to reduce lesion expansion. Nevertheless, with the inoculation technique used, it was not possible to evaluate the protective activity of fungicides, which can play an important role in their performance under field conditions. None of the fungicide treatments inhibited lesion expansion when applications were made on a curative basis. The residual effect was better on young than on mature trees. Paint treatments were generally more effective in reducing lesion expansion that drip chemigation or foliar sprays. However, this application method is laborious and becomes uneconomical in Spain. Trunk and branch sprays as well as long-term programs of foliar sprays or drip chemigation for control of spring and autumn infections are proposed as targets for future research.