Reproductive morphology and gonad development of the male seahorse, Hippocampus barbouri Jordan and Richardson 1908

The gross anatomy of the reproductive system and histology of the gonad in the juvenile and mature male seahorse, Hippocampus barbouri Jordan and Richarson 1908 are described and compared for the first time in this paper. The seahorse reproductive system does not differ from other teleost species except for the possession of a brooding pouch in males. The brood pouch is evident at 8-10 cm body length at 4-6 cm body length, a dark pigmentation is present at the site where the pouch is presumed to emerge. Paired gonads, a duct system and a shallow cloaca are observed. No anatomical connection is observed between the brood pouch and the reproductive system hence, the brood pouch is a secondary sex character. Sex differentiation is noted as early as 4-6 cm body length while sexual maturity is attained at 11-15 cm. The seahorse testis does not contain spermatocysts, and is of the unrestricted type since the spermatogonia are distributed along the entire length of the testicular tubule