Endocrine disruptors have devastating impacts on the reproductive physiology of aquatic organisms. The Gulf pipefish, Syngnathus scovelli , is a sexually dimorphic species, which demonstrates predictable morphological, physiological, behavioral, and genetic responses to synthetic estrogen exposure. It has broad geographic range, spanning freshwater marine environments, making it potential senti...

Mate choice is often based on multivariate suites of traits perceived in more than one sensory modality (Partan & Marler 2005). A variety of scenarios have recently been proposed to address how these complex sets of traits evolve (Candolin 2003; Hebets & Papaj 2005) and interact to elicit receiver responses (Rowe 1999; Partan & Marler 2005; Chenoweth & Blows 2006). Sex-role-reversed systems pro...

Discovery and development of new antitumor agents from abundant marine fish are attracting an increasing interest. In the present study, we extracted and purified a novel antitumor protein Syngnathusin from the whole body of Syngnathus acus L., a precious marine fish traditionally used for tumors. Syngnathusin was comprised of 16 kinds of amino acids, mainly acidic amino acids. Its molecular we...

The dorsal and pectoral fins are the primary locomotor organs in seahorses (Hippocampus) and pipefish (Syngnathus). The small dorsal fins beat at high oscillatory frequencies against the viscous medium of water. Both species are able to oscillate their fins at frequencies likely exceeding the point of flicker fusion for their predators, thus enhancing their ability to remain cryptic. High-speed...

In the pipefish Syngnathus typhle, pregnant males provide all parental care. Females are able to produce more eggs than males can brood, and consequently females compete more intensely for mates than do males, a phenomenon defined as sex-role reversal. As the genetic mating system influences the operation of sexual selection, we investigate variation in one phenotypic component of mate quality,...

Differences among populations in the intensity of sexual selection resulting from distinct genetic mating systems can lead to divergent morphological evolution and speciation. However, little is known about how genetic mating systems vary between populations and what factors may contribute to this variation. In this study, we compare the genetic mating systems of two geographically distinct pop...

Genetic mating systems are expected to vary among and within populations in response to environmental and demographic factors. Despite the fact that mating system variation theoretically can have profound effects on important evolutionary processes such as sexual selection, extensive intraspecific surveys of geographical variation in mating systems are rare. We used microsatellite markers to ch...

The differential allocation hypothesis assumes that animals should weigh costs and benefits of investing into reproduction with a current mate against the expected quality of future mates, and predicts that they should invest more into reproduction when pairing with a high-quality mate. In the broad-nosed pipefish (Syngnathus typhle), males care for the embryos in a brood pouch and females comp...