Bacterial Flora of Milkfish, Chanos chanos, Eggs and Larvae.

Abstract

Aerobic bacterial flora of eggs and larvae of milkfish, Chanos chanos, was investigated. Microflora in the incubating water of egg, rearing water of larvae, water source, and larval food was also analyzed.Aerobic bacterial flora of milkfish eggs was largely influenced by the bacterial flora in the incubating water. Both in eggs and in the incubating water Pseudomonas species were the dominant bacteria. During milkfish larval rearing, intestinal aerobic bacterial flora was examined at days 1, 3, 7, 10, 15, 18, and 21. Bacterial number in the larvae and rearing water significantly increased during the culture period up to day 18 but dropped significant at day 21. Pseudomonas species were detected from yolk-sac larvae (day 1) as the dominant bacteria, similarly to the normal flora in the rearing water. However, intestinal bacteria were predominated with Vibrio species when the yolk-sac was absorbed on day 3. Larval rearing water, water source, and larval food contained predominantly Pseudomonas species.

Progress in fish gastrointestinal microbiota research

“…Moreover, the studies of Fernandez et al . () have demonstrated that the dominant Pseudomonas species of the bacterial flora of yolk‐sack larvae of milkfish, Chanoschanos (Forsskal), were similar to those of the rearing water. Additionally, several studies have revealed that, once feeding begins, the intestinal microflora was derived from the live feed ingested rather than the bacteria present in water (Muroga et al .…”

“…As the larval gut is sterile at the time of hatching, it is rapidly colonized by microbiota present in the environment, as well as those originally present on the chorion (Hansen & Olafsen 1989). Moreover, the studies of Fernandez et al (1996) have demonstrated that the dominant Pseudomonas species of the bacterial flora of yolk-sack larvae of milkfish, Chanoschanos (Forsskal), were similar to those of the rearing water. Additionally, several studies have revealed that, once feeding begins, the intestinal microflora was derived from the live feed ingested rather than the bacteria present in water (Muroga et al 1987;Tanasomwang & Muroga 1988;Munro et al 1993Munro et al , 1994Bergh et al 1994;Bergh 1995;Griez et al 1997).…”

Isolation and identification of Pseudoalteromonas piscicida strain Cura‐d associated with diseased damselfish (Pomacentridae) eggs

“…The mucosal surfaces of marine fish eggs are a good substrate for the adhesion and colonization of bacteria (Hansen & Olafsen 1989). In aquaculture, the microflora of marine fish eggs has been found to be dominated by the genera Pseudomonas, Pseudoalteromonas, Alteromonas, Aeromonas, Vibrio, Leucothrix and Flavobacterium (Hansen & Olafsen 1989;Fernandez, Tendencia, Lean Äo & Duray 1996). Oppenheimer (1955) and Shelbourne (1963) originally suggested that micro-organisms could cause mortality of marine fish eggs.…”

EFFECT OF COPPER IONS ON GROWTH AND BACTERIAL ABUNDANCE IN THE INTESTINAL TRACT OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) LARVAE

“…The colonization of the larval intestine seems to follow a two-step pattern (Ringø et al 1996;Ringø & Vadstein 1998). Populations of aerobic heterotrophic bacteria present in the gastrointestinal tract of turbot larvae, estimated using the dilution plate tech- (Fernandez et al 1996;Ringø & Birkbeck 1999). The gastrointestinal tract should provide a ready source of nutrients for bacteria in the form of partially digested dietary components or secretion and mucus, which is continuously secreted in the digestive tract of fish.…”

“…Some studies have established that bacteria, which colonize the gastrointestinal tract of non-fed fish larvae, originate from the resident egg epiflora at the time of hatching (Hansen & Olafsen 1989. Other studies on the bacterial flora of yolk-sac larvae of the milkfish (Chanos chanos) demonstrated that the dominant Pseudomonas species were similar to those of the rearing water (Fernandez et al 1996). However, Strøm & Ringø (1993) showed that the primary gut flora of 4-day-old larvae of the Atlantic cod was affected by exposing the fish to a moderate concentration of Lactobacillus plantarum.…”