Behavioral assay and chemical characters of female sex pheromones in the hermit crab Pagurus filholi

Abstract

Males of the hermit crab Pagurus filholi perform assessment behavior toward females, as a preliminary step of precopulatory guarding, during the reproductive season. It is known that such behavior is elicited by female sex pheromones, but the compounds involved have never been characterized in this species. Several experiments were conducted to develop a reliable bioassay along with purification procedures to identify potential compounds with pheromonal activity in Pagurus filholi. We developed a bioassay protocol to assess pheromonal activity by using an empty shell with cotton containing either artificial seawater (control) or test water. We measured and compared the time duration of male assessment behavior toward each shell if the test water contained female sex pheromones. Ultra-filtering of seawater samples potentially containing pheromones showed that the compound was <1 kDa in molecular weight. Males showed precopulatory assessment behavior toward “female conditioned” water samples treated with open column purification and eluted with MeOH, suggesting that compounds triggering male behavior were low polar molecules. Molecules with pheromonal activity were not volatile after freeze drying, effective even after heating to 90 °C, and remained active in seawater at 12 °C even after 6 days from sample collection, which suggests a rather stable characteristic of the female sex pheromones of this species.

Interspecific hybridization of decapod crustacean species with commercial interest—A review

“…38 Pheromones, animal maturation and the moult stage are some factors that influence natural copulation in crustaceans. 39 Sexual pheromones, which are responsible for mating behaviour in several decapod species, are released in general by females [40][41][42] and detected by the males' first antenna or whip antennular (olfactory organs). 39,43,44 Particularly in shrimps, distance pheromones can be released both by females to stimulate searching and/or courtship behaviours in males, 40 or by males to attract females.…”

Research frontiers in penaeid shrimp reproduction: Future trends to improve commercial production

“…Aquatic organisms like terrestrial animals use olfaction and gustation as chemoreception mechanisms for activating biological processes such as reproduction, social interactions, food acquisition, shelter, and defense (Derby and Sorensen, 2008). Chemical signals in crustaceans have been demonstrated in many groups; however, identification of sex pheromones in decapod crustaceans has been inconclusive or incomplete (Derby and Sorensen, 2008;Okamura et al, 2017)).…”

“…A reliable species-specific bioassay is essential to identify sex pheromones (Okamura et al, 2017). These authors developed a precopulatory guarding bioassay for the hermit crab, Pagurus filholi, for the basic chemical characterization of the pheromone involved.…”

Cross-sensory interference assessment after exposure to noise shows different effects in the blue crab olfactory and sound sensing capabilities

“…Crustacean species, which are reported to be adversely impacted by high amplitude anthropogenic noise exposure (Edmonds et al, 2016), use chemical cues to regulate critical aspects of their behaviour (Hay, 2009). Crustaceans use species-specific olfactory cues to find food (Roberts and Laidre, 2019a), localize potential prey (Keller et al, 2003;Tran, 2013;Weissburg and Zimmer-Faust, 1994), avoid predators (Berger and Butler, 2001), select dens (Berger and Butler, 2001;Nevitt et al, 2000), and in odour-associative learning and odour discrimination (Steullet et al, 2002), conspecific interactions, including couple localization and mating (Giri and Dunham, 2000;Karavanich and Atema, 1998;Okamura et al, 2017;Valdes and Laidre, 2019), shell finding (hermit crabs) (Valdes and Laidre, 2018), and grooming (Daniel et al, 2001).…”