A releaser pheromone that attracts males in the urine of mature female masu salmon

Abstract

A releaser pheromone of masu salmon Oncorhynchus masou was investigated using Y-maze behavioural experiments. During the reproductive season, urine of mature females contains a releaser pheromone which acts as a sex attractant for spermiating mature male parr. The releaser pheromone in mature female urine is one or more low molecular weight substances (less than 10 000) soluble in ether under basic conditions. The attractant was not present in either the coelomic fluid of ovulated females nor in neutral or acidic extracts of female urine which contain free steroids and F-type prostaglandins, respectively.1999 The Fisheries Society of the British Isles

Species-specific releaser effect of urine from ovulated female masu salmon and rainbow trout

“…Adult-sized immature and ovulated females of masu salmon and rainbow trout were catheterized to collect the urine as described previously (Yambe et al, 1999). The fishes were held without feeding in outdoor tanks (1000 l) supplied with well water for 2 days before the catheterization.…”

“…In salmonid fishes, the urine of mature females or hormones [steroid-conjugates or F type-prostaglandins (PGFs)] in the urine have been reported to act as primer pheromones, which enhance plasma levels of sex steroids and gonadotrophin II and the amount of milt in males Moore & Waring, 1996;Vermeirssen et al, 1997;Moore & Olsén, 2000). Urine has also been shown to be the main source of releaser pheromones in a number of fish species (Colombo et al,1982;Adams et al, 1987;Yamazaki, 1990;Katsel et al, 1992;Yambe et al, 1999;Yambe & Yamazaki, 2001).…”

“…Some examples are 3 , 17-dihydroxy-5 -pregnen-20-one-glucuronide in African catfish Clarias gariepinus (Burchell) (Resink et al, 1987), PGF 2 or 15-keto-PGF 2 in goldfish, Carassius auratus (L.) (Sorensen et al, 1988), 13,14-dihydro-15-keto-PGF 2 in cobitide loach, Misgurnus anguillicaudatus (Cantor) (Kitamura et al, 1994b), 17,20 -dihydroxy-4-pregnen-3-one (17,20 -P) inducing avoidance behaviour in crucian carp Carassius carassius (L.) (Bjerselius et al, 1995), tetrodotoxin in puffer fish Takifugu niphobles (Jordan & Snyder) (Matsumura, 1995), testosterone in Atlantic salmon Salmo salar L. parr (Moore, 1991), and PGF 2 in Arctic charr, Salvelinus alpinus (L.) (Sveinsson & Hara, 1995). In addition, Yambe et al (1999) reported that, in masu salmon Oncorhynchus masou (Brevoort) the sex attractants for mature males are basic substances extracted from ovulated female urine, but not neutral and acidic extracts which contain sex steroids or PGFs, respectively. However, there have not been sufficient behavioural experiments that simultaneously test different species under the same conditions to clearly determine whether releaser pheromones are species-specific in fishes.…”

Transitions of urine flow rate and kidney-somatic index in mature masu salmon

“…In salmonid fish, sex pheromones, which attract conspecific mature males or induce priming effects of final maturation, were present in the urine of ovulated females. [11][12][13][14][15] It was also suggested in masu salmon that avoidance pheromone was contained in the urine of mature males. 16 Therefore, when compared with immature fish, it has been speculated that the kidney in mature fish modifies functionally, suggesting either urine production or accumulation.…”

Effects of feeding time on approaching behavior to food odor in goldfish

“…The Y-maze flow-through system has been used to examine the behavioral reactions in avoidancepreference in fish. 5,6…”