Developing Methods for Harvesting Rosy Red Fathead Minnow Eggs

Abstract

We evaluated the effectiveness of different types of spawning substrates in retaining the eggs of rosy red fathead minnow Pimephales promelas, the potential substrate preference of the fish, and the effectiveness of different concentrations of sodium sulfite for detaching eggs from substrates without affecting egg survival. Egg adherence was determined by placing replicate sections of four types of conveyor belt material of varying roughness into a pool stocked with fathead minnow. A screened tray was suspended below each substrate to catch the eggs that did not adhere. Substrate preference was evaluated by following a similar protocol, but only three males were stocked (equal to the number of replicates of each substrate). To test the efficacy of sodium sulfite in removing eggs, substrates with eggs were placed in 0.0, 1.5, and 3.0% solutions and uniformly agitated. The effect of exposure time and egg age was tested by exposing eggs to a 1.5% solution of sodium sulfite for 0 (control), 5, 10, 15, 20, 25, and 30 min. The two rougher substrates retained a significantly greater percentage of eggs than the two smoother ones (72–77% versus 34–39%). Nest locations near the water inlet and air stones were preferred regardless of substrate type. The 1.5% sodium sulfite solution was as effective as the 3.0% solution in removing eggs from substrates. There were no significant differences in hatching rate or percentage of atypical fry resulting from exposure of eggs to 1.5% sodium sulfite for up to 30 min. An egg harvesting system consisting of placing a rough or textured substrate in well‐aerated locations and subsequent egg removal with sodium sulfite appears to be feasible, although economic questions remain.

Vertical Transmission of Ovipleistophora ovariae (Microspora) within the Eggs of the Golden Shiner

“…After treatments, egg samples from each of the four mat sections The remaining eggs from all four treatments were placed in a hatching system similar to that used by Masson et al (2006), which consisted of 50-mL hatching tubes with a flow of aerated water drawn from a deep well and delivered through sealed pipes. One half was disinfected in a 150-mg/L formalin bath for 30 min (a common industry practice).…”

Effect of Spawning Substrate Area to Male Ratio on Fathead Minnow Egg Production

“…In addition, parasites may be transferred from adults to the young, and any wild fish accidentally stocked with the broodfish may spawn and be mixed together with the fathead minnow crop. A new hatchery method for fathead minnow (Clemment and Stone 2004;Masson et al 2006;Horne et al 2010) involves supplying spawning substrate on which males will establish nests to collect eggs for indoor hatching. Stocking fry from a hatchery provides control over density, separates adults from young, and excludes unwanted fish species.…”

Effects of Diets with or without Menhaden Fish Meal and Oil on Egg Size, Hatchability, and Fry Size for Rosy Red Fathead Minnow

“…However, the hatching data were more variable than in other studies. Kahl et al (2001) reported a hatching percentage of 84 6 6.7% for fathead minnow eggs, and Masson et al (2006) obtained a hatching percentage of 49-54%. Diet was not an experimental variable either in Kahl et al (2001) or Masson et al (2006).…”

“…Kahl et al (2001) reported a hatching percentage of 84 6 6.7% for fathead minnow eggs, and Masson et al (2006) obtained a hatching percentage of 49-54%. Diet was not an experimental variable either in Kahl et al (2001) or Masson et al (2006). No difference in hatching percentage of the eggs or larval weights were observed in Nile tilapia Oreochromis niloticus fed diets containing either soybean oil or fish oil (El-Sayed et al 2005).…”

“…Mean egg diameters (mm) and fry lengths (mm) were determined using an image capture analysis system (Image Pro Plus, Media Cybernetics, Bethesda, Maryland). The eggs were placed in a hatching system (Masson et al 2006), and hatching success (percent hatched) was computed as 100 (number of eggs hatched/total number of eggs).…”