This study focuses on female life-history parameters and reproductive cycles for four mobulid rays (Mobula thurstoni, Mo. japanica, Mo. tarapacana, and Manta birostris) caught in a targeted fishery in the Philippines. We collected size and reproductive data from 1,510 specimens (30% of catch) landed in two seasons in 2015 and 2016. Sexual maturity was assessed by visual examination of 1,034 specimens, to determine size-at-maturity and size-at-pregnancy. Females of all species matured at a larger size than males. Pregnancy ogives were estimated for all species except Mo. tarapacana, and shifted to the right of female maturity ogives, suggesting that only a small percentage of the female reproduce upon reaching sexual maturity. We report an aseasonal reproductive cycle at the population level for both Mo. thurstoni and Ma. birostris due to the absence of specific ovulation cycle and the wide size ranges of embryos examined throughout the months. The development of the follicles is not always synchronous with gestation, supporting the theory of a resting period between pregnancies. Our results show the low reproductive potential of these species and their conservative life history, and suggest that population growth rates previously reported are an overestimate.

1Source for dog population size estimation: Municipal Agriculture Office; Bureau of Agricultural Statisctics; House to house survey by barangay livestock aid (BALA).2Method of dog vaccination campaign: House to house only; *Mixture of central point and house to house.3After 2007, incidence was calculated using the more conservative dog population estimate e.g. for 2008, 100,752 dogs was used.*N.B. Omitted data means data is missing because it was not collected, and therefore is not necessarily zero.

Meta-analyses of prevalence of S. japonicum by preventive chemotherapy status and population group in Bohol and Leyte provinces (1954–2015).