Bacteria associated with sardine (Sardina pilchardus) eggs in a natural environment (Ría de Vigo, Galicia, northwestern Spain)

Abstract

The present study was undertaken to describe the epiflora of the eggs of an important fishing species collected in a coastal zone. Microflora associated with sardine (Sardina pilchardus) eggs collected in the Ría de Vigo was examined from January to June 2000. The count was carried out in three different ways: a total direct count by epifluorescence, a heterotrophic bacteria count on marine agar (MA) and a total vibrio count on thiosulfate citrate bile sucrose (TCBS). It was observed that the counts of total bacteria by epifluorescence were always higher by 2-3 logarithms than the bacterial counts on MA, and by 3-4 logarithms than the count of vibrios on TCBS. In both cases the differences were statistically significant. Throughout the sampling period only a slight variation was observed in the counts undertaken, and in the measured physicochemical parameters. For the qualitative study, 250 strains isolated from MA and 81 strains recovered on TCBS were identified. Members of the genera Vibrio, Pseudoalteromonas, Pseudomonas and Moraxella were found to dominate on the culturable adherent microflora of sardine eggs and Aeromonas, Tenacibaculum (Flexibacter), Flavobacterium and Cytophaga spp. were present in minor amounts. Vibrio anguillarum and Vibrio fischeri, pathogens of fish larvae, as well as Tenacibaculum ovolyticum, a pathogen of fish eggs, were detected.

Assessment of the effects of confinement in the spider crabMaja brachydactylaBlass, 1922 broodstock

“…In this sense, bacteria have been isolated from the haemolymph of apparently healthy spider crab 1975; Tubiash, Sizemore & Colwell 1975;Welsh & Sizemore 1985;Davis & Sizemore 1982), the red swamp crawfish (Procambarus clarkii (Girard, 1852); Scott & Thune 1986) and the freshwater prawn (Macrobrachium rosenbergii (De Man, 1879); Brady & Lasso de la Vega 1992). As water was not sterilized at the entrance of the system, microbiological composition might be more affected during summer months compared with the rest of the year (Miguez & Combarro 2003), due to higher water temperature. All the above mentioned studies clearly support the need to know the bacterial populations in the haemolymph of healthy crustaceans to correctly interpret diagnostic results.…”

Characterization of the bacterial community associated with the surface and mucus layer of whiting (Merlangius merlangus)

“…To survive in this highly competitive environment, microorganisms will exploit every possible niche available, including the colonization of nutrient‐rich surfaces of other marine organisms such as fish. Bacteria associated with the surface of marine fish eggs (Miguez & Combarro, 2003), larvae (Verner‐Jeffreys et al , 2003) and the surface and gut (for a review see Hansen & Olafsen, 1999) of a small number of adult fish species have previously been described using culture‐based methods. More recently, culture‐independent approaches have been applied to characterize the bacterial assemblage in the hind gut of marine herbivorous fish (Moran et al , 2005; Fidopiastis et al , 2006; Clements et al , 2007).…”

Diversity of vibrios in the haemolymph of the spider crab Maja brachydactyla

“…Other phenotypic studies from Galicia also rendered a low vibrio species diversity dominated by the Splendidus clade (Toranzo et al. 1993; Miguez and Combarro 2003).…”

“…2003). It has been found that the Vibrio species’ composition changes as the seawater temperature changes (Miguez and Combarro 2003); members of the Harveyi clade ( Vibrio core group) predominate when the temperatures are above 20°C, and those from the Splendidus clade when it is below that (Maeda et al. 2003).…”