Alteration of the brood pouch morphology during gestation of male seahorses, Hippocampus kudaParichart Laksanawimol A , Praneet Damrongphol A B C and Maleeya Kruatrachue A
A Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
B Center for Reproductive Biology of Economic Aquatic Animal, Institute of Science and Technology for Research and Development, Mahidol University, Nakornpathom 73170, Thailand.
C Corresponding author. Email: firstname.lastname@example.org
Marine and Freshwater Research 57(5) 497-502 https://doi.org/10.1071/MF05112
Submitted: 16 June 2005 Accepted: 8 March 2006 Published: 29 June 2006
The brood pouch of seahorses can be divided into four sequential stages based on the characteristics of the altered tissue layers during gestation: the normal stage, the embryo-carrying stage, the embryo-release stage and the repair stage. The brood pouch is composed of a folded inner pseudostratified columnar epithelium and a smooth outer stratified cuboidal epithelium. Three tissue layers between the inner and the outer epithelia are an inner loose connective tissue layer, a middle smooth muscle layer and an outer dense irregular connective tissue layer. In the normal stage, the inner loose connective tissue layer is thick and vascularised with small blood vessels; the muscle layer consists of scattered unorganised muscle fibres. In the embryo-carrying stage, the inner epithelial and inner loose connective tissue layers become distended and highly vascularised with enlarged blood vessels. In the embryo-release stage, the inner loose connective tissue layer is extensively vascularised with very large blood vessels and the smooth muscle fibres invade the outer dense irregular connective tissue layer. Structures altered during gestation gradually resume their normal condition in the repair stage. Extensive vascularisation of the brood pouch during gestation suggests an intricate paternal–embryo relationship implying other significant roles besides protective function of the pouch.
Extra keywords: embryo, reproductive season, Syngnathidae.
The authors would like to thank P. D. Round for critical reading of the manuscript. This work was supported by a grant from the Institute of Science and Technology for Research and Development, Mahidol University.
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