Common Carp Implanted with Prostaglandin F2α Release a Sex Pheromone Complex that Attracts Conspecific Males in Both the Laboratory and Field

Abstract

When ovulated, female fish of many species are known to release a F-prostaglandin-derived sex pheromone that attracts conspecific males. Recently, this pheromone was identified in the common carp as a mixture of prostaglandin F(2α) (PGF(2α)) and unidentified body metabolites, which we termed a 'pheromone complex.' The present study sought to test the activity of this pheromone complex in the field by developing a system using carps implanted with PGF(2α) as pheromone donors. An initial experiment determined that osmotic pumps that delivered up to 0.4 mg of PGF(2α) per hour could be implanted into carp without any apparent effects on their health. A second experiment found that PGF(2α)-implanted male and female carp released biologically relevant (and equivalent) quantities of PGF(2α), along with two of its seemingly inactive metabolites, for up to 2 weeks. Laboratory experiments demonstrated that the odor of PGF(2α)-implanted carp was highly attractive to male conspecifics, and included necessary body metabolites; it attracted males as strongly as ovulated carp odor, and much better than PGF(2α) alone. Finally, a field test demonstrated that PGF(2α)-implanted female carp attracted mature male, but not female carp, from a distance of 20 m. This is the first demonstration of the activity of a PGF(2α)-based pheromone in a natural environment and confirms the use of a PGF-pheromone complex in the carp. We suggest that the implant technique may be useful in future studies of how PGF pheromones function and could be further developed to attract invasive fish for use in control.

Olfactory sensitivity to steroid glucuronates in Mozambique tilapia suggests two distinct and specific receptors for pheromone detection

“…Common to both of these cichlids is that they neither detect prostaglandins nor unconjugated steroids (of those that have been tested). In this they differ substantially from Cypriniformes, such as goldfish (Sorensen et al, 1988;Sorensen et al, 1995) and carp (Lim and Sorensen, 2011;Lim and Sorensen, 2012); Salmoniformes, e.g. Atlantic salmon (Moore and Waring, 1996), brown trout and brook trout (Essington and Sorensen, 1996) and Arctic char (Sveinsson and Hara, 2000); and even the Perciformes, such as the round goby (Murphy et al, 2001).…”

Attracting Common Carp to a bait site with food reveals strong positive relationships between fish density, feeding activity, environmental DNA, and sex pheromone release that could be used in invasive fish management

“…Further, given that laboratory females released at least 30 times more PGF 2 a than males, it seems highly likely that mature females were the primary source. Because spawning mature females even higher quantities of PGF 2α and a few of its metabolites, this technique could be expanded to determine precise reproductive state (Lim & Sorensen, 2012; Sorensen & Johnson, 2016). The PGF 2α release rates that we measured in mature female Carp were similar to those measured by Lim and Sorensen (2012) in mature Carp prior to spawning.…”

“…Because spawning mature females even higher quantities of PGF 2α and a few of its metabolites, this technique could be expanded to determine precise reproductive state (Lim & Sorensen, 2012; Sorensen & Johnson, 2016). The PGF 2α release rates that we measured in mature female Carp were similar to those measured by Lim and Sorensen (2012) in mature Carp prior to spawning. Unlike previous studies on nesting Sea Lamprey, Petromyzon marinus , our study described a relationship between pheromone concentration and abundance in streams.…”

“…Deuterated PGF 2α (500 ng; Cayman Chemical, Ann Arbor, MI, USA) was added to each 1‐L water sample to serve as an internal standard, after which water samples were extracted by passing them through activated reverse‐phase C18 columns (Sep‐Pak, Waters Inc., Milford, MA, USA) following established techniques (Lim & Sorensen, 2012). Columns were eluted with 5 ml of methanol (Sigma‐Aldrich, St. Louis, MO, USA), and dried under a stream of nitrogen (see Fine & Sorensen, 2005).…”

“…Further, they are especially well understood in the family cyprinidae and the Carps in particular (Sorensen & Stacey, 2004; Stacey & Sorensen, 2009). Prostaglandin F 2α (PGF 2α ), a pheromone released by mature female Common Carp and their relatives (Stacey & Sorensen, 2009), as well many other species (as parts of mixtures), is especially interesting because it has proven to be measurable using mass spectrometry (MS) (Lim & Sorensen, 2011, 2012). However, PGF 2α has not yet been systematically measured in natural waters and its likely relationship to the distribution and abundance of wild fish as well as the distribution of their eDNA is also presently unknown.…”