Ripley Jennifer L
Department of Biology, West Virginia University, 53 Campus Drive, PO Box 6057, Morgantown, WV 26506, USA.
Comp Biochem Physiol A Mol Integr Physiol. 2009 Sep;154(1):98-104. doi: 10.1016/j.cbpa.2009.05.003. Epub 2009 May 15.
Even though sea horses, sea dragons, and pipefishes of the teleost family Syngnathidae have been studied for over a century, the physiological significance of the paternal brood pouch is not well defined. Here we document the regulation of brood pouch osmolality during embryonic development for Syngnathus floridae and Syngnathus fuscus, particularly during the middle brood stages or around hatching. S. fuscus brood pouch osmolality was significantly lower than non-brooding conspecifics for all brood stages, but early and late stage S. floridae displayed pouch osmolality comparable to non-brooding males, suggesting brood pouch osmoregulation at these stages may be important for S. fuscus embryonic development. Quantification of Na(+), K(+), Ca(2+), and Mg(2+) in paternal blood plasma, pouch fluid, and embryos indicated that regulation of these ions contributes to pouch osmoregulation and furthermore, that ions in the brood pouch are most likely derived from the environment and not paternal blood. While both species displayed significant increases in dry mass and changes in embryonic ion concentrations during development, net uptake of paternally-derived ions was not documented. Overall, this examination furthers our understanding of syngnathid brood pouch physiology and offers insight into the evolution of paternal care in these fishes.
尽管硬骨鱼科海龙科的海马、海龙和管口鱼已经被研究了一个多世纪，但雄性育儿袋的生理意义仍未明确界定。在这里，我们记录了佛罗里达海蠋鱼和棕海蠋鱼胚胎发育过程中育儿袋渗透压的调节情况，特别是在育儿中期或孵化前后。在所有育儿阶段，棕海蠋鱼育儿袋的渗透压均显著低于未育儿的同种个体，但佛罗里达海蠋鱼的早期和晚期育儿袋渗透压与未育儿的雄鱼相当，这表明在这些阶段育儿袋的渗透调节可能对棕海蠋鱼的胚胎发育很重要。对雄鱼血浆、育儿袋液和胚胎中的钠、钾、钙和镁进行定量分析表明，这些离子的调节有助于育儿袋的渗透调节，此外，育儿袋中的离子很可能来自环境而非雄鱼的血液。虽然两个物种在发育过程中干重都显著增加，胚胎离子浓度也发生了变化，但未记录到来自父本的离子的净摄取。总体而言，这项研究进一步加深了我们对海龙科育儿袋生理学的理解，并为这些鱼类父性抚育的进化提供了见解。
