About Syngnathus floridae (Jordan & Gilbert, 1882)
The dusky pipefish (Syngnathus floridae) is a species of pipefish. It is widespread in the western Atlantic Ocean, with a range extending from Bermuda, Chesapeake Bay (United States), the northern Gulf of Mexico, and the Bahamas, south through the western Caribbean Sea to Panama. This is a marine, subtropical, demersal fish. It lives at depths of up to 22 metres (72 ft), and is most commonly found at depths no greater than 4 metres (13 ft). The maximum recorded body length of this species is 25 centimetres (9.8 in). Like other species in the genus Syngnathus, S. floridae shows sex-role reversal between males and females during mating and offspring care. During copulation, females deposit their eggs into a brood pouch located on the male. Males then fertilize the eggs and provide all post-zygotic care: they physically carry the eggs, and transfer nutrients to developing embryos through a placenta-like connection. Eggs hatch approximately 10 days after fertilization, and newly hatched individuals are immediately independent of parental care. Dusky pipefish are polygynandrous, meaning both males and females mate with multiple partners. Males act as the limiting sex in this species, because their brood pouch can only hold a fixed maximum number of eggs at one time. By contrast, females produce more eggs than they are able to deposit, so females have unlimited reproductive success. Sexual selection acts on body size in this species, favoring larger males. Larger males can carry more eggs and attract more female mates, so larger males have higher reproductive success than smaller males. Environmental variation between dusky pipefish populations affects their reproductive success. Water temperature plays a major role in shaping reproductive success through its impact on sexual selection. As water temperature increases, the potential rate of reproduction rises for both males and females, but it increases faster for males. This means that temperature alters sexual selection by selecting against females with slower reproductive rates. Higher water temperatures also improve reproductive success by increasing the number of eggs a female produces, which in turn reduces the number of mates a male needs to fill his brood pouch. In lower temperature environments, males have lower reproductive success, because they do not accept as many eggs in these conditions.
