The reproductive biology of the drab seahorse, Hippocampus fuscus was investigated at two sites (Great Bitter Lakes and Lake Timsah) in the Suez Canal, Egypt, to determine sex ratio, reproductive maturity stages, gonad index, spawning
season, and male/female fecundity. A total of 393 seahorses were collected from Great Bitter Lakes and 319 from Lake Timsah from August 2006 to July 2007. Male to female ratios did not depart significantly from a 1:1 ratio, either through the whole study period or between the seasons. Female seahorses progressed through three ovarian maturity
stages during the reproductive cycle: Previtellogenic ovaries, Vitellogenic ovaries, and Mature ovaries. Hippocampus fuscus appears to undergo year-round reproduction in the Suez Canal, as reproductively mature females and brooding males with eggs/embryos in the brood pouch were captured every month of the year, although most mature
specimens were collected in mid winter–early summer. The peak of female gonadosomatic index (GSI) coincided with the peak occurrence of mature ovaries in female seahorses. Vitellogenesis in female seahorses appears to be asynchronous. Female H.fuscus were relatively more fecund in Lake Timsah than in Great Bitter Lake; where fecundity ranged from 160 to 686 ova in Lake Timsah and from 86 to 372 ova in Great Bitter Lake. At both sites, female fecundity was positively correlated with seahorse height, total weight, and gonad weight. Male H. fuscus was also relatively more fecund
(number of eggs and/or embryos in the brood pouch). Male fecundity was positively correlated to seahorse height. Female H. fuscus appeared to have higher fecundity than males in the sampled populations (i.e., mean number of ripe ova or clutch size exceeds the mean brood number). This study is so far the first to document aspects of the
reproductive biology of H. fuscus in the Suez Canal and adds to our knowledge of this relatively poorly studied seahorse species.